VIEWPOINT(TM) CK SYSTEM
Device Facts
| Record ID | P010018 |
|---|---|
| Device Name | VIEWPOINT(TM) CK SYSTEM |
| Applicant | Refractec, Inc. |
| Product Code | MWD · Ophthalmic |
| Decision Date | Apr 11, 2002 |
| Decision | APPR |
| Device Class | Class 3 |
| Attributes | Therapeutic |
Indications for Use
The ViewPoint™ CK System / Conductive Keratoplasty™ (CK™) Procedure is indicated for the temporary reduction of spherical hyperopia in patients who have 0.75 D to 3.25 D of cycloplegic spherical hyperopia, less than or equal to 0.75 D of refractive astigmatism (minus cylinder format), a cycloplegic spherical equivalent of 0.75 D to 3.00 D, and are 40 years of age or greater with a documented stability of refraction for the prior 12 months, as demonstrated by a change of less than 0.50 D in spherical and cylindrical components of the manifest refraction. The magnitude of correction with this treatment diminishes over time, with some patients retaining some or all of their intended refractive correction.
Device Story
ViewPoint™ CK System uses radiofrequency (RF) energy to treat spherical hyperopia via Conductive Keratoplasty™ (CK™). System includes RF console, handpiece, disposable stainless steel Keratoplast™ Tip, lid speculum (return electrode), and footpedal. Physician inserts tip into corneal stroma; RF energy induces controlled collagen shrinkage, creating peripheral tightening and central corneal steepening. Procedure performed in clinic. Console monitors output; patient treatment card activates system. Default parameters (60% power, 0.6s) are fixed for US market. Output steepening corrects hyperopia; effect is temporary and may diminish over time. Benefits include non-laser refractive correction for presbyopic-age patients.
Clinical Evidence
Prospective, multi-center study (IDE #G980224) of 401 eyes (233 subjects). Primary endpoints: preservation of BSCVA (safety) and predictability of MRSE within ±1.00 D (effectiveness). At 12 months, 89% of eyes were within ±1.00 D of target MRSE; 56% achieved UCVA 20/20 or better. Safety: 0% of eyes lost >2 lines of BSCVA at 12 months. Adverse events included corneal scratch, perforation, and transient postoperative symptoms (glare, halos, dryness). Histopathology confirmed stromal thermal footprint without inflammatory response.
Technological Characteristics
RF electrosurgical device. Components: RF console, pen-shaped handpiece, disposable 420 series stainless steel Keratoplast™ Tip (90 µm diameter, 450 µm length), lid speculum return electrode. Standards: ISO/EN 60601-1 (Electrical Safety), ISO/EN 60601-1-2 (EMC), ISO 10993 (Biocompatibility), ISO 11135 (ETO Sterilization). Fixed parameters (0.6W, 0.6s). Software controls user interface, diagnostics, and error logging to patient treatment card.
Indications for Use
Indicated for temporary reduction of spherical hyperopia in patients ≥ 40 years old with 0.75-3.25 D cycloplegic spherical hyperopia, ≤ 0.75 D refractive astigmatism, and 0.75-3.00 D cycloplegic spherical equivalent, with stable refraction (change < 0.50 D) over prior 12 months.
Submission Summary (Full Text)
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P010018
SUMMARY OF SAFETY AND
EFFECTIVENESS DATA
ViewPoint™ CK System
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# TABLE OF CONTENTS
Page
I. GENERAL INFORMATION ... 3
II. INDICATIONS FOR USE ... 3
III. CONTRAINDICATIONS ... 3
IV. WARNINGS AND PRECAUTIONS ... 4
V. DEVICE DESCRIPTION ... 4
VI. ALTERNATIVE PRACTICES OR PROCEDURES ... 6
VII. MARKETING HISTORY ... 6
VIII. POTENTIAL ADVERSE EFFECTS OF THE DEVICE ON HEALTH ... 7
IX. SUMMARY OF PRECLINICAL STUDIES ... 7
A. Objectives ... 7
B. Design Verification ... 7
C. Electrical Safety Tests ... 7
D. EMC Compliance ... 7
E. Physical Tests ... 8
F. Physical Safety Tests ... 8
G. Biocompatibility ... 8
H. Performance Testing ... 8
I. Electrical and Thermal Simulation ... 9
J. Histopathology ... 9
K. Conclusions ... 10
X. SUMMARY OF CLINICAL STUDIES ... 10
A. Objectives ... 10
B. Study Design ... 11
C. Study Plan and Subject Assessments ... 14
D. Study Period and Investigational Sites ... 14
E. Demographic Data ... 15
F. Data Analysis and Results ... 16
XI. CONCLUSIONS DRAWN FROM THE STUDIES ... 29
XII. PANEL RECOMMENDATION ... 29
XIII. CDRH DECISION ... 30
XIV. APPROVAL SPECIFICATIONS ... 30
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# I. GENERAL INFORMATION
Device Generic Name: RF Electrosurgical Device
Device Trade Name: ViewPoint™ CK System
Applicant's Name and Address: Refractec, Inc.
5 Jenner, Suite 150
Irvine, California 92618 U.S.
(949) 784-2600
(949) 784-2601 (fax)
Date of Panel Recommendation: 11/30/2001
PMA Number: P010018
Date of GMP Inspection: July 25, 2001
Date of Notice of Approval to Applicant: April 11, 2002
# II. INDICATIONS FOR USE
The ViewPoint™ CK System / Conductive Keratoplasty™ (CK™) Procedure is indicated for the temporary reduction of spherical hyperopia in patients who have 0.75 D to 3.25 D of cycloplegic spherical hyperopia, less than or equal to 0.75 D of refractive astigmatism (minus cylinder format), a cycloplegic spherical equivalent of 0.75 D to 3.00 D, and are 40 years of age or greater with a documented stability of refraction for the prior 12 months, as demonstrated by a change of less than 0.50 D in spherical and cylindrical components of the manifest refraction. The magnitude of correction with this treatment diminishes over time, with some patients retaining some or all of their intended refractive correction.
# III. CONTRAINDICATIONS
Conductive Keratoplasty™ treatment with the ViewPoint™ CK System is contraindicated in:
- Patients with a peripheral pachymetry reading, measured at the 6 mm optical zone, of less than 560 microns.
- Patients who have had previous strabismus surgery or are likely to develop strabismus following the CK™ procedure.
- Patients with a history of Herpes zoster or Herpes simplex keratitis.
- Patients who have diabetes, diagnosed autoimmune disease, connective tissue disease, or clinically significant atopic syndrome.
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- Patients who are being treated with chronic systemic corticosteroid or other immunosuppressive therapy that may affect wound healing, and any immunocompromised patients.
- Patients who are pregnant or lactating.
- Patients with keratoconus.
- Patients with a history of keloid formation.
- Patients with intractable keratoconjunctivitis sicca.
- Patients with implantable electrical devices (pacemakers, defibrillators, cochlear implants, etc.).
- Patients with narrow angles.
## IV. WARNINGS AND PRECAUTIONS
The warnings and precautions can be found in the device labeling.
## V. DEVICE DESCRIPTION
The ViewPoint™ CK System is designed to treat spherical, previously untreated hyperopia of 0.75 to 3.25 D through a procedure known as Conductive Keratoplasty™ (CK™).
Conductive Keratoplasty™ utilizes low energy, delivered directly into the corneal stroma through a handpiece and Keratoplast™ Tip, to effect refractive change in the cornea. As a result of conducting a controlled amount of radiofrequency energy into the corneal stroma, the desired collagen shrinkage temperature is achieved. The peripheral application of this treatment in a predetermined pattern creates a band of tightening and results in a steepening of the central cornea. This steepening results in the desired refractive effect.
## Overview of the ViewPoint™ CK System
The ViewPoint™ CK System used to perform the CK™ procedure consists of the following components:
- Radiofrequency energy-generating console
- Reusable corneal marker
- Reusable lid speculum with cable and connector
- Reusable hand-held, pen-shaped handpiece with cable and connector
- Footpedal
- Disposable Keratoplast™ Tip
- Patient treatment card
Refractec submitted declarations that the ViewPoint™ CK System conforms to the following standards:
- ISO/EN 60601-1 Electrical Safety
- ISO/EN 60601-1-2 EMC
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- ISO/EN 60601-2-2 Electrical Safety For RF
- ISO/EN 60601-1-4 Programmable Electrical Medical Systems
- ISO 10993 Biocompatibility
- ISO 10993-7 ETO Residuals
- ISO 11135 ETO Sterilization
## ViewPoint™ CK System Console
A patient treatment card is inserted into the console to activate the system. The energy level is set at 60% power (0.6W) with a treatment time of 0.6 seconds. Selection of parameters outside the default settings is not allowed in the U.S. market version. An AC powered, portable, low power, energy source provides regulated radiofrequency energy through the handpiece to the Keratoplast™ Tip.
## Handpiece
The handpiece is a hand-held, reusable, pen-shaped instrument attached by a removable cable and connector to the console. The radiofrequency energy is delivered by means of the Keratoplast™ Tip, which attaches to the handpiece.
## Keratoplast™ Tip
A sterile, disposable, stainless steel, Keratoplast™ Tip, 90 µm in diameter and 450 µm long, that delivers radiofrequency energy directly to the corneal stroma, is attached to the handpiece. The Keratoplast™ Tip has a proximal bend of 45° and a distal bend of 90° to allow access to the cornea over the patient’s brow and nasal regions. A Teflon® stop at the very distal portion of the stainless steel tip assures correct depth of penetration. The Keratoplast™ Tip must not be used on fellow eyes or subsequent patients.
## Lid Speculum
The lid speculum serves as the return (dispersive) electrode for the radiofrequency energy being delivered through the Keratoplast™ Tip. Two types of specula are offered: Barraquer type and Lancaster type. The Barraquer type is a small, malleable wire-speculum and the Lancaster is a locking speculum. The Lancaster lid speculum was not used in the clinical investigation of the device, but is considered equivalent for the purpose of a return electrode.
## Footpedal
The footpedal attaches to the console and controls the release of radiofrequency energy.
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## Patient Treatment Card
A patient treatment card is inserted into the console to activate the system.
## Safety Features
The ViewPoint™ CK System has numerous features to assure proper operation. The ViewPoint™ CK System includes safety checks at start-up and monitors output during treatment.
## Software
The ViewPoint™ CK System software controls the user interface, and provides the user with system diagnostics and error messages in the event of a device anomaly. Additionally, the software saves all error messages to the patient treatment card to assist in the diagnosis of technical issues.
## VI. ALTERNATIVE PRACTICES OR PROCEDURES
Alternative methods of correcting farsightedness (hyperopia) include: spectacles, contact lenses, laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and laser thermal keratoplasty (LTK).
## VII. MARKETING HISTORY
The ViewPoint™ CK System has not been marketed in the United States. The ViewPoint™ CK System was first marketed outside the United States in March 2001. Refractec, Inc. has 27 ViewPoint™ CK Systems located in 15 countries (Australia, Brazil, Argentina, Mexico, Canada, United Kingdom, France, Finland, Spain, Italy, Germany, Greece, Saudi Arabia, South Africa, and Paraguay). The ViewPoint™ CK System has not been withdrawn from any country or market for reasons of safety and effectiveness.
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# VIII. POTENTIAL ADVERSE EFFECTS OF THE DEVICE ON HEALTH
Potential adverse events associated with the $\mathrm{CK}^{\mathrm{SM}}$ procedure include: decrease in BSCVA of > 10 letters not due to irregular astigmatism as shown by hard contact lens refraction at 6 months or later, IOP > 25 mm Hg, secondary surgical intervention other than CK treatment, late onset of haze beyond 6 months with loss of 2 lines (10 letters) or more BSCVA, a corneal epithelial defect involving the treatment site, corneal edema, corneal microbial infection, corneal decompensation, corneal scar in the visual axis, intraocular infection, hypopyon, hyphema, onset of cataract unrelated to age/systemic disease/ trauma, retinal detachment, retinal vascular accidents.
Please refer to the complete listings of adverse events and complications observed during the clinical study, which are presented on pages 22 and 23 in the Summary of Clinical Studies section.
# IX. SUMMARY OF PRECLINICAL STUDIES
## A. Objectives
Preclinical studies were conducted to establish the safety and performance of the ViewPoint™ CK System.
## B. Design Verification
Upon completion of the assembly and testing of prototype units, the output of the device was evaluated to assess the waveform and to verify that the output met the original design intent. This report concluded that the waveform generated by the prototype device meets the design intent.
## C. Electrical Safety Tests
The device has been designed to comply with electrical standards that are recognized domestically and internationally. EN 60601-1 and EN 60601-2-2 Test Reports completed by Intertek Testing Service concluded that the device meets all of the applicable elements of these standards.
## D. EMC Compliance
The device has been designed and tested to assure that the unit meets the applicable elements on EN 60601-1-2. The test report completed by Intertek Testing Service concluded that the device meets this standard for EMC compliance.
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E. Physical Tests
1. Treatment probe dimensional/physical properties testing:
Qualification of the manufacturing and assembly process was conducted to verify that dimensional specifications were met and that process variability was within acceptable limits. Testing included dimensional analysis, visual inspection of the tip after repeated insertions and activation of radiofrequency energy, and evaluation of the glue bond between the Teflon® stop and the tip. The test report shows that the tip dimensions fall within an acceptable tolerance range, the glue bond is sufficient to withstand forces encountered during the procedure, and that repeated insertion and conductance of radiofrequency energy does not adversely affect the tip.
2. Return Electrode Heat Transfer Study:
A study was conducted to confirm that there are no adverse heating effects at the return electrode (the lid speculum). This study confirmed that the radiofrequency energy applied to the treatment probe caused localized heating at the treatment site and that there was no evidence of heating at the return electrode.
F. Physical Safety Tests
Sterility Validation and Expiration Dating: The device is terminally sterilized in its package utilizing a 100% ETO cycle that has been validated. The sterilization cycle provides a 10⁻⁶ Sterility Assurance Level (SAL). Accelerated and Real Time aging studies confirm the labeled expiration date.
G. Biocompatibility
The contact material of the tip is a medical grade 420 series Stainless Steel. This material is of known biocompatibility.
H. Performance Testing
Each device is evaluated against a Final Test Procedure as part of the manufacturing/assembly process. This Test Procedure includes calibration and verification of the critical waveform parameters as well as other performance criteria. The Test Procedure has been completed as part of the manufacturing process validation on five prototype units. The results of these tests are on file with the contract manufacturer and as part of the Design History File at Refractec. The results of the validation were found to be acceptable.
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# I. Electrical and Thermal Simulation
Computer simulation of the ViewPoint™ CK System was performed in order to analyze the power deposition pattern and thermal profile surrounding the needle tip. This simulation consisted of two steps. First, the needle tip was assigned a voltage with respect to the return electrode; other boundary conditions were defined on the surface of a rectangular volume as required. This information was analyzed by using a computer program to solve the Laplace equation to calculate the potential distribution within the volume. The electric field, power density, and circuit impedance were then calculated. Once power density was identified, this value was used as the heating source input into a program that solved a bioheat equation, calculating the temperature distribution within the volume as a function of time. The applied power was then modified to simulate the effect of tissue coagulation or desiccation that occurs over time.
Temperature distributions were computed throughout the entire simulation volume. Based on the power deposition patterns computed from the electric field modeling program, the highest temperatures were predicted to be achieved along the axis of the needle and near the needle tip. At a distance from the needle, where power deposition was insignificant, increase in temperature was due to thermal conduction effects. While initially, maximum heating occurred near the needle tip, with increasing temperature, heating extended along the needle shaft, and ultimately spread at later points to tissue elements located further away from the tip. The extent of the thermal lesion produced was shown to be a function of both time and temperature.
# J. Histopathology
As part of the clinical evaluation of the ViewPoint™ CK System, six subjects scheduled for penetrating keratoplasty underwent the CK℠ procedure 24 to 48 hours prior to penetrating keratoplasty (PK). Histology was performed on the corneal tissue obtained from these subjects.
Initially, the corneal tissue was examined to determine the exact location of the radiofrequency applications, and to ensure that the section selected for histopathologic processing did not have any evidence of the underlying pathology that necessitated penetrating keratoplasty. The selected specimen was then processed and stained, and evaluated under high-powered light microscopy.
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Histopathologic examination revealed a V-shaped or U-shaped stromal thermal footprint at the site of the radiofrequency application that clearly demarcated the shrunken collagen from the surrounding preserved lamellae. A bullous-like separation of epithelium from the underlying Bowman's layer, or a total absence of epithelium at the site of the $\mathrm{CK}^{\mathrm{SM}}$ application was observed. Epithelial cells at the site of the $\mathrm{CK}^{\mathrm{SM}}$ application were abnormal, with necrotic, shrunken nuclei. Bowman's layer remained intact in all of the sections examined. The keratocyte population was decreased or shrunken, with edema between the stromal lamellae, and collagen disorganization. The surrounding stroma maintained its normal staining properties, with preservation of collagen structure and keratocyte nuclei. No inflammatory cells were observed within the area of the $\mathrm{CK}^{\mathrm{SM}}$ application. Descemet's membrane was continuous, with no folds.
Based on this histological study of human corneas, it can be concluded that Conductive Keratoplasty$^{\mathrm{SM}}$ was not associated with an inflammatory response, and no damage to either Bowman's layer or Descemet's membrane in the areas of application was observed.
## K. Conclusions
The preclinical testing provided evidence to support the conclusion that the device did not present an unreasonable risk to subjects and could proceed to clinical trials under an approved investigational device exemption (IDE).
## X. SUMMARY OF CLINICAL STUDIES
Refractec, Inc. conducted a clinical study of the ViewPoint™ CK System in the U.S. under IDE #G980224. The data from this study served as the basis for the approval decision. Safety and effectiveness outcomes through 12 months post-treatment were evaluated for confirmation.
### A. Objectives
The objective of the clinical study was to evaluate the safety and effectiveness of the ViewPoint™ CK System in the correction of low to moderate spherical hyperopia.
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B. Study Design
This study was a prospective, multi-center clinical study where the primary control was the preoperative status of the treated eye.
1. Inclusion and Exclusion Criteria
Enrollment in the Refractec clinical study was limited to patients who:
- Had 0.75 to 3.25 D of manifest spherical hyperopia, ≤ 0.75 D of refractive astigmatism, and 0.75 to 3.00 D of spherical equivalent by cycloplegic refraction in the eye to be treated.
- Had spherical equivalent manifest refraction and spherical equivalent cycloplegic refraction that did not differ by more than 0.50 D.
- Discontinued using hard or rigid gas permeable contact lenses for at least 3 weeks and discontinued using soft contact lenses for at least 2 weeks prior to the preoperative evaluation in the eye to be treated.
- For hard contact lens wearers – had 2 central keratometry readings and 2 manifest refractions taken at least one week apart, the last of which did not differ from the previous values by more than 0.50 D in either meridian; mires were regular in the eye to be treated.
- Had visual acuity correctable to at least 20/40 in both eyes.
- Were at least 21 years of age.
- Were willing and able to return for scheduled follow-up examinations for 24 months after surgery.
- Provided written informed consent.
- Were able to tolerate their full cycloplegic correction while not under cycloplegia.
Patients with the following conditions were excluded from the study:
- Previous strabismus surgery, or who would have been likely to develop strabismus following the CK^{SM} procedure.
- Anterior segment pathology, including cataracts (in the operative eye).
- Any corneal abnormality (in the operative eye).
- Progressive or unstable hyperopia (in the operative eye).
- Latent hyperopia.
- Distorted or unclear corneal mires.
- Blind in the fellow eye.
- Previous intraocular or corneal surgery.
- History of Herpes zoster or Herpes simplex keratitis.
- History of steroid-responsive rise in IOP, glaucoma, or preoperative IOP > 21 mm Hg.
- At risk for angle closure or with a potentially occludable angle.
- Diabetes, diagnosed autoimmune disease, connective tissue disease, or clinically significant atopic syndrome.
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- Chronic systemic corticosteroid or other immunosuppressive therapy, and any immunocompromised patients.
- Using ophthalmic medication(s) other than artificial tears for treatment of any ocular pathology.
- Using systemic medications with significant ocular side effects.
- History of keloid formation.
- Intractable keratoconjunctivitis sicca.
- Pregnant, planning to be pregnant, or lactating during the course of the study.
- Known sensitivity to planned study concomitant medications.
- Participating in any other ophthalmic drug or device clinical trial during the time of this clinical investigation.
- Peripheral pachymetry reading of less than 560 microns.
- Distance UCVA better than 20/32.
## 2. Study Endpoints
The following primary study parameters were evaluated in the determination of safety and effectiveness of the Refractec ViewPoint™ CK System.
### Primary Safety Parameter:
- Preservation of best corrected visual acuity: less than 5% of eyes should lose more than two lines of best corrected visual acuity at the postoperative interval at which stability has been established.
### Primary Effectiveness Parameter:
- Predictability: 75% of eyes should have a manifest refraction spherical equivalent within ±1.00 D of the attempted correction at the postoperative interval at which stability has been established.
The following secondary study parameters were evaluated in the determination of safety and effectiveness of the Refractec ViewPoint™ CK System.
### Secondary Safety Parameters:
- Preservation of best corrected visual acuity: less than 1% of eyes with preoperative BSCVA of 20/20 should have a visual acuity outcome worse than 20/40 BSCVA at the postoperative interval at which stability has been established.
- Mean extent of induced manifest refractive astigmatism: less than 5% of eyes should have a postoperative manifest refractive astigmatism
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that varies from target amount by greater than 2.00 D at the postoperative interval at which stability has been established.
- Results of slit lamp examination: less than 1% of eyes should have clinically significant haze, defined as a decrease in BSCVA of >2 lines not due to irregular astigmatism, at the postoperative interval at which stability has been established.
- Central endothelial cell loss: mean endothelial cell loss should be no more than 10% at the postoperative interval at which stability has been established.
- Cumulative incidence of adverse events. Adverse events should occur in less than 5% of eyes and any single adverse event should occur in less than 1% of eyes.
## Secondary Effectiveness Parameters:
- Predictability: 50% of eyes should have a manifest refraction spherical equivalent within ± 0.50 D of attempted correction at the postoperative interval at which stability has been established.
- Stability (absence of change in refractive outcome over time): 95% of eyes should have a change of ≤ 1.00 D in manifest refraction spherical equivalent between two refractions performed at least three months apart.
- Improvement in uncorrected visual acuity: 85% of eyes who had 20/20 or better spectacle-corrected visual acuity preoperatively, and for whom the intended target correction was emmetropia should have an uncorrected visual acuity of 20/40 or better at the postoperative interval at which stability has been established. For those eyes which had spectacle-corrected visual acuity of worse than 20/20 but at least 20/40 preoperatively, and for which the intended target correction was emmetropia, 75% should have an uncorrected visual acuity of 20/40 or better at the postoperative interval at which stability has been established.
- Decrease in manifest refraction spherical equivalent and astigmatism: 75% of eyes should be within ± 1.00 D of attempted spherical and astigmatism correction at the postoperative interval at which stability has been established.
- Subject satisfaction as measured by subjective questionnaire.
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C. Study Plan and Subject Assessments
1. Study Plan
All subjects were expected to return for follow-up examinations at one day, one week, and 1, 3, 6, 9, 12, and 24 months post-treatment. After the first 50 eyes were evaluated, the option to perform simultaneous bilateral surgery was left to the discretion of the investigator. Retreatments were not attempted in this study.
2. Subject Assessments and Efficacy Criteria
- Distance visual acuity, uncorrected and best spectacle-corrected, using ETDRS charts
- Manifest refraction (no auto-refraction)
- Cycloplegic refraction
- Pachymetry
- Intraocular pressure (applanation)
- Slit lamp examination
- Fundus examination (dilated)
- Specular microscopy of the central and peripheral corneal endothelium (in a subgroup of 100 subjects)
- Mesopic contrast sensitivity, with and without glare (subgroup)
- Computerized corneal topography (postoperatively in eyes with anomalous refractive outcomes)
- Central keratometry
- Subject self-evaluation/questionnaire
D. Study Period and Investigational Sites
Subjects were treated between 2/10/1999 and 12/01/2000 at 12 investigational sites. The database for this PMA cohort reflected data collected through 10/01/2001 and included 401 eyes: 233 primary eyes and 168 fellow eyes.
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# E. Demographic Data
Of the 233 subjects, 58% were female and 42% were male. The mean age for all enrolled subjects was 55.3 years, with a range from 40 to 73 years. The study population consisted primarily of Caucasians (81%). Mean hyperopia (CRSE) prior to surgery was 1.86 diopters.
Table 1
Demographics
All Eyes Enrolled
| 401 Eyes of 233 Enrolled Subjects | | |
| --- | --- | --- |
| Gender | Male | 42% |
| | Female | 58% |
| Race | Caucasian | 81% |
| | Black | 9% |
| | Asian | 2% |
| | Other | 9% |
| Eye | Left | 49% |
| | Right | 51% |
| Age (yrs) | N | 233 |
| | Mean | 55.3 |
| | 95% Confidence Interval | 54.5,56.1 |
| | Standard Deviation | 6.36 |
| | Median | 55.6 |
| | Range | 40.2,73.9 |
| Range of Treatment - CRSE | N | 401 |
| | Mean | 1.86 |
| | 95% Confidence Interval | 1.80,1.92 |
| | Standard Deviation | 0.628 |
| | Median | 1.75 |
| | Range | 0.75,4.00 |
| Range of Treatment - MRSE | N | 401 |
| | Mean | 1.80 |
| | 95% Confidence Interval | 1.74,1.86 |
| | Standard Deviation | 0.637 |
| | Median | 1.75 |
| | Range* | -0.38,3.75 |
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F. Data Analysis and Results
The protocol was amended after enrollment of the initial cohort of 54 eyes to reflect a decrease in the maximum spherical hyperopia to be corrected by $\mathrm{CK}^{\mathrm{SM}}$. A modified nomogram that shifted the treatment ranges and number of spots also reduced the maximum $\mathrm{CK}^{\mathrm{SM}}$ treatment from $4.00\,\mathrm{D}$ to $3.25\,\mathrm{D}$ spherical hyperopia (CRSE $3.00\,\mathrm{D}$). Thus the nomogram identified as "current nomogram" specifies a treatment range of $0.75\,\mathrm{D}$ to $3.25\,\mathrm{D}$ spherical hyperopia, a spherical equivalent of $0.75\,\mathrm{D}$ to $3.00\,\mathrm{D}$, and no more than $0.75\,\mathrm{D}$ absolute cylinder.
Of the 54 eyes that underwent $\mathrm{CK}^{\mathrm{SM}}$ during the first phase of study, only 25 eyes fit into the modified $\mathrm{CK}^{\mathrm{SM}}$ nomogram. The remaining 29 eyes fell outside of the treatment ranges defined in the modified nomogram, identified throughout this report as the "current nomogram," which was used for the remainder of the study. Since these 29 eyes were not treated with the current nomogram, their refractive outcomes do not reflect the effectiveness of the current nomogram, and on this basis, they have been excluded from the effectiveness outcomes, i.e., uncorrected visual acuity, accuracy of intended (target) to achieved refraction, expressed as spherical equivalent manifest refraction or MRSE, and mean postoperative refraction, also expressed as MRSE. An additional 9 eyes were treated outside the current nomogram as a result of protocol deviations or surgeon error, and have also been excluded from analyses of effectiveness. All eyes have been included in analyses of the stability and safety parameters.
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# 1. Pre-Treatment Characteristics
Table 2 presents a summary of the pre-treatment visual acuity and refraction. The treatment goal for all eyes was emmetropia.
Table 2 Preoperative Refractive Parameters Eyes Treated with Current Nomogram
| | | Primary Eyes | | Fellow Eyes | | All Eyes | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Spherical Equivalent (MRSE) * | 0.0-0.99 D | 11 | 6% | 11 | 7% | 22 | 6% |
| | 1.0-1.99 D | 121 | 61% | 84 | 52% | 205 | 57% |
| | 2.0-2.99 D | 62 | 31% | 63 | 39% | 125 | 35% |
| | 3.0-4.00 D | 5 | 3% | 4 | 2% | 9 | 2% |
| | Total | 199 | 100% | 162 | 100% | 361 | 100% |
| Cylinder (manifest) ** | 0.00 D | 69 | 35% | 57 | 35% | 126 | 35% |
| | 0.25 D | 41 | 21% | 38 | 23% | 79 | 22% |
| | 0.50 D | 59 | 30% | 49 | 30% | 108 | 30% |
| | 0.75 D | 28 | 14% | 18 | 11% | 46 | 13% |
| | 1.00 D | 3 | 2% | 1 | 1% | 4 | 1% |
| | 1.25 D | 0 | 0% | 0 | 0% | 0 | 0% |
| | Total | 200 | 100% | 163 | 100% | 363 | 100% |
| Spherical Equivalent (CRSE) ** | 0.0-0.99 D | 8 | 4% | 9 | 6% | 17 | 5% |
| | 1.0-1.99 D | 117 | 59% | 85 | 52% | 202 | 56% |
| | 2.0-2.99 D | 65 | 33% | 60 | 37% | 125 | 34% |
| | 3.0-4.00 D | 10 | 5% | 9 | 6% | 19 | 5% |
| | Total | 200 | 100% | 163 | 100% | 363 | 100% |
| Cylinder (cycloplegic) ** | 0.00 D | 69 | 35% | 67 | 41% | 136 | 37% |
| | 0.25 D | 29 | 15% | 36 | 22% | 65 | 18% |
| | 0.50 D | 75 | 38% | 39 | 24% | 114 | 31% |
| | 0.75 D | 26 | 13% | 21 | 13% | 47 | 13% |
| | 1.00 D | 1 | 1% | 0 | 0% | 1 | <1% |
| | 1.25 D | 0 | 0% | 0 | 0% | 0 | 0% |
| | Total | 200 | 100% | 163 | 100% | 363 | 100% |
* Excludes two ineligible eyes with minus MRSE; these eyes are included in the cylinder analysis.
** Includes one ineligible eye with $>0.75$ D cycloplegic cylinder.
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## 2. Subject Accountability
Of the 401 eyes enrolled in the study, follow-up data through 12 months postoperative are available for 344 eyes (95%). Of the remaining eyes, one (<1%) was discontinued from the study, 4 eyes (1%) were lost to follow-up, and 14 eyes (4%) were not yet eligible for the visit.
Table 3
Accountability
Eyes Treated with Current Nomogram
| | Month 1 | | Month 3 | | Month 6 | | Month 9 | | Month 12 | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Available for Analysis | 354/363 | 98% | 358/363 | 99% | 352/363 | 97% | 350/363 | 96% | 344/363 | 95% |
| Discontinued | 1/363 | <1% | 1/363 | <1% | 1/363 | <1% | 1/363 | <1% | 1/363 | <1% |
| Missed Visit | 8/363 | 2% | 4/363 | 1% | 10/363 | 3% | 10/363 | 3% | 0/363 | 0% |
| Not yet eligible for interval | 0/363 | 0% | 0/363 | 0% | 0/363 | 0% | 0/363 | 0% | 14/363 | 4% |
| Lost to Follow-up | 0/363 | 0% | 0/363 | 0% | 0/363 | 0% | 2/363 | 1% | 4/363 | 1% |
| Accountability | 354/363 | 98% | 358/363 | 99% | 352/363 | 97% | 350/363 | 96% | 344/349 | 99% |
## 3. Summary of Key Effectiveness Variables
Table 4 demonstrates that the key effectiveness outcomes at 6 months postoperative meet or exceed the outcomes recommended in the October 10, 1996 FDA Guidance for Refractive Surgery Lasers.
Table 4
Summary of Key Efficacy Variables
Eyes Treated with Current Nomogram
| | Month 1 | Month 3* | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- | --- | --- |
| Efficacy Variables | | | | | |
| UCVA 20/20 or better | 29% | 40% | 45% | 49% | 56% |
| UCVA 20/25 or better | 51% | 63% | 64% | 73% | 75% |
| UCVA 20/40 or better | 79% | 86% | 90% | 93% | 92% |
| MRSE ≤ 0.50 D | 47% | 56% | 61% | 63% | 62% |
| MRSE ≤ 1.00 D | 75% | 83% | 88% | 87% | 89% |
| MRSE ≤ 2.00 D | 94% | 97% | 99% | 99% | 99% |
* Two eyes were excluded from the 3 Month MRSE efficacy variables due to manifest refraction and BSCVA not performed.
{18}
Table 5
Summary of Key Efficacy Variables at 12 Months
Preoperative MRSE Stratified by Dioptric Group
Eyes Treated with Current Nomogram
| | 0.00 to 0.99 D | 1.00 to 1.99 D | 2.00 to 3.25 D |
| --- | --- | --- | --- |
| Efficacy Variables | | | |
| UCVA 20/20 or better | 64% | 59% | 48% |
| UCVA 20/25 or better | 73% | 77% | 72% |
| UCVA 20/40 or better | 91% | 94% | 90% |
| MRSE ≤ 0.50 D | 82% | 68% | 50% |
| MRSE ≤ 1.00 D | 100% | 94% | 78% |
| MRSE ≤ 2.00 D | 100% | 100% | 98% |
Table 6
Summary of Key Efficacy Variables at 12 Months
Stratified by Treatment Spots Applied
Eyes Treated with Current Nomogram
| | 8 Spots* | 16 Spots* | 24 Spots* | 32 Spots* |
| --- | --- | --- | --- | --- |
| Efficacy Variables | | | | |
| UCVA 20/20 or better | 67% | 63% | 49% | 49% |
| UCVA 20/25 or better | 80% | 77% | 73% | 71% |
| UCVA 20/40 or better | 93% | 96% | 92% | 87% |
| MRSE ≤ 0.50 D | 100% | 70% | 60% | 41% |
| MRSE ≤ 1.00 D | 100% | 96% | 92% | 67% |
| MRSE ≤ 2.00 D | 100% | 100% | 100% | 97% |
* 8 spots = CRSE 0.75 to 0.875 D
16 spots = CRSE 1.00 to 1.625 D
24 spots = CRSE 1.75 to 2.25 D
32 spots = CRSE 2.375 to 3.00 D
{19}
# 4. Change in Manifest Refraction Over Time
Table 7 Stability of Manifest Refraction through 12 Months Patients with Consecutive visits All Eyes Treated
| | Between 3 and 6 Months | Between 6 and 9 Months | Between 9 and 12 Months |
| --- | --- | --- | --- |
| Change in MRSE ≤ 0.50 D | 74% | 89% | 88% |
| Change in MRSE ≤ 0.75 D | 87% | 95% | 96% |
| Change in MRSE ≤ 1.00 D | 93% | 98% | 97% |
| Change in MRSE | | | |
| Mean | 0.26 | 0.10 | 0.14 |
| 95% Confidence Interval | 0.20,0.32 | 0.06,0.14 | 0.10,0.18 |
| Standard Deviation | 0.493 | 0.372 | 0.362 |
| Change in MRSE per Month | | | |
| Mean | 0.09 | 0.03 | 0.05 |
| 95% Confidence Interval | 0.07,0.11 | 0.01,0.05 | 0.03,0.07 |
| Standard Deviation | 0.164 | 0.124 | 0.121 |
Table 8 Mean MRSE by Visit 12 Month Cohort Eyes Treated with Current Nomogram
| | Baseline | 1 Month | 3 Months | 6 Months | 9 Months | 12 Months |
| --- | --- | --- | --- | --- | --- | --- |
| N | 325 | 325 | 323 | 325 | 325 | 325 |
| Mean | 1.77 | -0.56 | -0.29 | -0.04 | 0.05 | 0.19 |
| 95% Confidence Interval | 1.71,1.83 | -0.66,-0.46 | -0.37,-0.21 | -0.12,0.04 | -0.03,0.13 | 0.11,0.27 |
| Standard Deviation | 0.587 | 0.889 | 0.781 | 0.727 | 0.692 | 0.662 |
# a. Factors Associated with Outcomes
Statistical modeling performed on the data generated in the $\mathrm{CK^{SM}}$ clinical study found no effect of age, race, sex or clinical site on outcomes.
{20}
b. Subject Satisfaction
Subjects were asked to rate their quality of vision compared to before the Conductive Keratoplasty℠ (CK℠) procedure. Table 9 shows the percentage of subjects that rated each condition as improvement that was “extreme,” “marked,” “moderate,” “slight,” or “no improvement”.
Table 9
Quality of Vision
| | Month 1 | | Month 3 | | Month 6 | | Month 9 | | Month 12 | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Extreme Improvement | 83/353 | 24% | 87/361 | 24% | 109/370 | 29% | 115/366 | 31% | 112/369 | 30% |
| Marked Improvement | 149/353 | 42% | 159/361 | 44% | 164/370 | 44% | 144/366 | 39% | 160/369 | 43% |
| Moderate Improvement | 68/353 | 19% | 78/361 | 22% | 57/370 | 15% | 67/366 | 18% | 61/369 | 17% |
| Slight Improvement | 37/353 | 10% | 22/361 | 6% | 28/370 | 8% | 28/366 | 8% | 26/369 | 7% |
| No Improvement | 16/353 | 5% | 15/361 | 4% | 12/370 | 3% | 12/366 | 3% | 10/369 | 3% |
Overall subject satisfaction was assessed on a subject survey at 1, 3, 6, 9, and 12 months post-treatment using a 5-point grading scale from “very satisfied” to “very dissatisfied”.
Table 10
Subject Satisfaction
| | Month 1 | | Month 3 | | Month 6 | | Month 9 | | Month 12 | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Very Satisfied | 161/356 | 45% | 168/362 | 46% | 172/371 | 46% | 181/366 | 49% | 185/369 | 50% |
| Satisfied | 112/356 | 31% | 118/362 | 33% | 134/371 | 36% | 110/366 | 30% | 115/369 | 31% |
| Neutral | 57/356 | 16% | 55/362 | 15% | 34/371 | 9% | 42/366 | 11% | 34/369 | 9% |
| Dissatisfied | 16/356 | 4% | 12/362 | 3% | 20/371 | 5% | 21/366 | 6% | 27/369 | 7% |
| Very Dissatisfied | 10/356 | 3% | 9/362 | 2% | 11/371 | 3% | 12/366 | 3% | 8/369 | 2% |
Table 11
Need for Distance Correction
| | Month 1 | Month 3 | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- | --- | --- |
| No | 84% | 89% | 87% | 82% | 82% |
| Yes | 16% | 11% | 13% | 18% | 18% |
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{21}
Page 22 of 30
# 5. Summary of Key Safety Variables
The following table demonstrates that the key safety outcomes meet or exceed the outcomes recommended in the October 10, 1996 FDA Guidance for Refractive Surgery Lasers.
Table 12 Summary of Key Safety Variables All Eyes Treated
| | Month 1 | Month 3 | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- | --- | --- |
| Safety Variables* | | | | | |
| Loss of 2 lines BSCVA | 6% | 5% | 4% | 3% | 2% |
| Loss of > 2 lines BSCVA | 2% | 1% | 1% | 1% | 0% |
| BSCVA worse than 20/40 | 0% | 0% | 0% | 0% | 0% |
| Increase > 2.00 D cylinder | 3% | 2% | 1% | <1% | <1% |
| BSCVA worse than 20/25 | 4% | 2% | 1% | 1% | 0% |
| if 20/20 or better preoperatively | | | | | |
* Two eyes were excluded from all safety variables due to manifest refraction and BSCVA not performed.
Table 13 Summary of Key Safety Variables at 12 Months Preoperative MRSE Stratified by Dioptric Group All Eyes Treated
| | 0.00 to 0.99 D | 1.00 to 1.99 D | 2.00 to 3.25 D* |
| --- | --- | --- | --- |
| Safety Variables | | | |
| Loss of 2 lines BSCVA | 0% | 3% | 1% |
| Loss of > 2 lines BSCVA | 0% | 0% | 0% |
| BSCVA worse than 20/40 | 0% | 0% | 0% |
| Increase > 2.00 D cylinder | 0% | <1% | 0% |
| BSCVA worse than 20/25 | 0% | 0% | 0% |
| if 20/20 or better preoperatively | | | |
* Safety variables shown for all treated eyes; includes 2 eyes with preoperative MRSE > 3.25. Neither of these eyes lost ≥ 2 lines BSCVA, had BSCVA worse than 20/40, or increased > 2.00 D cylinder.
{22}
Table 14
Summary of Key Safety Variables at 12 Months
Stratified by Treatment Spots Applied
All Eyes Treated
| | 8 Spots* | 16 Spots* | 24 Spots* | 32 Spots* |
| --- | --- | --- | --- | --- |
| Safety Variables | | | | |
| Loss of 2 lines BSCVA | 0% | 3% | 3% | 0% |
| Loss of > 2 lines BSCVA | 0% | 0% | 0% | 0% |
| BSCVA worse than 20/40 | 0% | 0% | 0% | 0% |
| Increase > 2.00 D cylinder | 0% | 1% | 0% | 0% |
| BSCVA worse than 20/25 | 0% | 0% | 0% | 0% |
| if 20/20 or better preoperatively | | | | |
* 8 spots = CRSE 0.75 to 0.875 D
16 spots = CRSE 1.00 to 1.625 D
24 spots = CRSE 1.75 to 2.25 D
32 spots = CRSE 2.375 to 3.00 D
The following adverse events were reported in clinical study of the ViewPoint™ CK System.
Table 15
Adverse Event Summary
| | Month 1 | Month 3 | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- | --- | --- |
| Decrease in BSCVA of > 10 letters not due to irregular astigmatism as shown by hard contact lens refraction at 6 months or later | 0% | 0% | 0% | 0% | <1% |
| IOP >25 mm Hg | 0% | 0% | 1% | <1% | <1% |
| Secondary Surgical Intervention other than CK treatment | 0% | 0% | 0% | 0% | <1% |
| Other | 1% | 1% | <1% | 1% | 1% |
In clinical studies of the ViewPoint™ CK System, the following complication was reported on the day of surgery with a reported rate of <1%:
- Corneal scratch
The following adverse events were reported on the day of surgery at a rate of <1%:
- Corneal perforation
- Procedure could not be performed and had to be rescheduled due to technical difficulties with the CK$^{\text{SM}}$ device
Page 23 of 30
{23}
Each of the following complications was reported at the one week visit at a rate of less than 1%:
- Blurred vision
- Conjunctivitis
- Double vision
- Stye
The following adverse reaction was reported at one week at a rate of less than 1%:
- Mild iritis
During the first week following surgery patients may experience: pain, discomfort, a feeling of something in the eye lasting from one up to three days after surgery, mild light sensitivity, and swelling of the cornea.
Table 16 presents a summary of the complications reported in the clinical study.
Table 16
Complication Summary
All Eyes Treated
| | Month 1 | Month 3 | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- | --- | --- |
| Recurrent corneal erosion at one month or later | 0% | 1% | 0% | 0% | 0% |
| Double/ghost images in the operative eye | 1% | 1% | 2% | 1% | 1% |
| Foreign body sensation at one month or later | 0% | 0% | 0% | <1% | 0% |
| Pain at one month or later | 0% | 1% | 0% | 0% | 0% |
| Other | 2% | 3% | 2% | 1% | 1% |
The following complications were not reported in the clinical study, but could potentially occur following CK$^{\text{SM}}$ procedure: peripheral corneal epithelial defect; corneal edema.
Page 24 of 30
{24}
Table 17 below shows the absolute change in refractive cylinder for all eyes treated.
Table 17 Absolute Change in Refractive Cylinder All Eyes Treated
| Astigmatism | Month 1 | Month 3 | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- | --- | --- |
| Increase > 2.00 D | 3% | 2% | 1% | <1% | <1% |
| Increase > 1.00 D | 21% | 15% | 14% | 7% | 6% |
Table 18 presents a comparison of eyes with $>1.00$ D induced cylinder and eyes with $1.00$ D induced cylinder.
Table 18 Comparison of Eyes with $>1.00$ D Induced Cylinder and Eyes with $\leq 1.00$ D Induced Cylinder All Eyes Treated
| | ≤1.00 D Induced Cylinder | | >1.00 D Induced Cylinder | |
| --- | --- | --- | --- | --- |
| | Month 9 | Month 12 | Month 9 | Month 12 |
| Loss of ≥ 2 lines BSCVA | 4% | 3% | 4% | 0% |
| No Change (± 1 line) | 93% | 94% | 96% | 96% |
| Increase of ≥ 2 lines BSCVA | 3% | 4% | 0% | 5% |
| UCVA 20/20 or better | 52% | 57% | 9% | 35% |
| UCVA 20/25 or better | 75% | 76% | 43% | 47% |
| UCVA 20/40 or better | 93% | 94% | 83% | 71% |
| UCVA | | | | |
| N | 327 | 327 | 23 | 17 |
| Mean | 26.22 | 25.75 | 40.13 | 34.41 |
| 95% Confidence Interval | 24.81,27.63 | 24.30,27.20 | 25.23,55.03 | 25.83,42.99 |
| Standard Deviation | 13.034 | 13.460 | 36.462 | 18.056 |
| Median | 20.00 | 20.00 | 32.00 | 30.00 |
| Range | 12.50,100.00 | 12.50,100.00 | 20.00,200.00 | 16.00,80.00 |
{25}
Table 19 below shows the absolute shift in cylinder axis.
Table 19 Absolute Shift in Axis All Eyes Treated
| Induced Shift | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- |
| 0° to 15° | 34% | 37% | 39% |
| 16° to 30° | 19% | 16% | 16% |
| 31° to 45° | 11% | 10% | 9% |
| 46° to 60° | 11% | 12% | 10% |
| 61° to 75° | 12% | 12% | 15% |
| 76° to 90° | 15% | 14% | 10% |
Table 20 presents change in best spectacle visual acuity for all eyes treated.
Table 20 Change in Best Spectacle Corrected Visual Acuity All Eyes Treated
| | Month 1 | Month 3 | Month 6 | Month 9 | Month 12 |
| --- | --- | --- | --- | --- | --- |
| Decrease > 2 lines | 2% | 1% | 1% | 1% | 0% |
| Decrease 2 lines | 6% | 5% | 4% | 3% | 2% |
| Decrease 1 line | 29% | 27% | 27% | 22% | 22% |
| No Change | 48% | 51% | 51% | 54% | 54% |
| Increase 1 line | 12% | 13% | 16% | 18% | 18% |
| Increase 2 lines | 2% | 3% | 1% | 2% | 4% |
| Increase > 2 lines | 0% | 0% | 1% | 0% | 0% |
NOTE: At 6 months, $5\%$ (18/387) of eyes reported greater than or equal to 2 lines loss of BSCVA. Of these 18 eyes, $39\%$ (7/18) reported a BSCVA of 20/20 and $78\%$ (14/18) had a BSCVA of 20/25 or better. All but one eye (17/18) had 20/32 or better with no eye worse than 20/40. In regards to patient satisfaction specifically for these 18 eyes, half (9/18) reported being "Satisfied" or "Very Satisfied" while $28\%$ or 5 eyes reported being "Dissatisfied" or "Very Dissatisfied".
Subjects were asked to complete a questionnaire that allowed them to report any symptoms or complaints they had regarding their vision or ocular comfort following the procedure. Results for the subjective responses to these questionnaires at 6, 9, and 12 months post treatment are provided in Table 21.
{26}
Table 21
Subject Symptoms
All Eyes Treated
| | None | Mild | Moderate | Marked | Very Severe |
| --- | --- | --- | --- | --- | --- |
| Light Sensitivity | | | | | |
| Preop | 69% | 17% | 9% | 4% | 1% |
| Month 6 | 52% | 33% | 11% | 3% | 1% |
| Month 9 | 57% | 28% | 12% | 3% | 1% |
| Month 12 | 54% | 31% | 10% | 3% | 1% |
| Headaches | | | | | |
| Preop | 84% | 12% | 2% | 1% | 1% |
| Month 6 | 84% | 10% | 4% | 1% | 1% |
| Month 9 | 84% | 9% | 4% | 1% | 2% |
| Month 12 | 85% | 10% | 4% | 1% | 1% |
| Pain | | | | | |
| Preop | 95% | 4% | 1% | 0% | 0% |
| Month 6 | 91% | 7% | 1% | 1% | 1% |
| Month 9 | 92% | 6% | 1% | 0% | 1% |
| Month 12 | 96% | 3% | 0% | 1% | 1% |
| Redness | | | | | |
| Preop | 83% | 13% | 3% | <1% | 1% |
| Month 6 | 81% | 13% | 4% | 1% | 1% |
| Month 9 | 77% | 15% | 6% | 2% | 1% |
| Month 12 | 83% | 13% | 3% | 1% | <1% |
| Dryness | | | | | |
| Preop | 77% | 15% | 8% | 1% | 0% |
| Month 6 | 58% | 28% | 8% | 6% | 1% |
| Month 9 | 60% | 27% | 8% | 5% | 1% |
| Month 12 | 61% | 27% | 7% | 4% | 1% |
| Excessive Tearing | | | | | |
| Preop | 87% | 6% | 4% | 2% | 1% |
| Month 6 | 85% | 9% | 3% | 2% | 1% |
| Month 9 | 83% | 11% | 3% | 1% | 2% |
| Month 12 | 89% | 6% | 3% | 1% | 1% |
| Burning | | | | | |
| Preop | 88% | 9% | 2% | 1% | <1% |
| Month 6 | 83% | 12% | 3% | 2% | <1% |
| Month 9 | 82% | 11% | 5% | 2% | <1% |
| Month 12 | 85% | 12% | 2% | 1% | 0% |
| Gritty, Scratchy, or Sandy Feeling | | | | | |
| Preop | 83% | 14% | 2% | 0% | 0% |
| Month 6 | 79% | 13% | 4% | 3% | 0% |
| Month 9 | 82% | 14% | 3% | 1% | 1% |
| Month 12 | 81% | 14% | 4% | 0% | 1% |
Page 27 of 30
{27}
Table 21
Subject Symptoms
All Eyes Treated
(Continued)
| | None | Mild | Moderate | Marked | Very Severe |
| --- | --- | --- | --- | --- | --- |
| Glare | | | | | |
| Preop | 74% | 18% | 6% | 1% | 1% |
| Month 6 | 56% | 28% | 11% | 5% | 1% |
| Month 9 | 58% | 28% | 8% | 4% | 2% |
| Month 12 | 60% | 25% | 11% | 2% | 2% |
| Halos | | | | | |
| Preop | 90% | 7% | 2% | 2% | <1% |
| Month 6 | 63% | 21% | 8% | 5% | 2% |
| Month 9 | 66% | 21% | 9% | 2% | 2% |
| Month 12 | 65% | 21% | 8% | 3% | 2% |
| Blurred Vision | | | | | |
| Preop | 67% | 13% | 11% | 7% | 2% |
| Month 6 | 52% | 28% | 12% | 6% | 3% |
| Month 9 | 59% | 22% | 12% | 5% | 2% |
| Month 12 | 63% | 22% | 10% | 4% | 1% |
| Double Vision | | | | | |
| Preop | 90% | 5% | 5% | 1% | 0% |
| Month 6 | 67% | 17% | 8% | 6% | 3% |
| Month 9 | 74% | 13% | 7% | 4% | 1% |
| Month 12 | 77% | 14% | 5% | 3% | 1% |
| Fluctuation of Vision | | | | | |
| Preop | 84% | 12% | 3% | 1% | 0% |
| Month 6 | 54% | 29% | 8% | 7% | 1% |
| Month 9 | 60% | 25% | 7% | 5% | 3% |
| Month 12 | 60% | 28% | 7% | 4% | 1% |
| Variation in Vision in Bright Light | | | | | |
| Preop | 74% | 16% | 8% | 2% | <1% |
| Month 6 | 55% | 30% | 10% | 3% | 1% |
| Month 9 | 62% | 24% | 8% | 5% | 1% |
| Month 12 | 58% | 28% | 9% | 4% | 1% |
| Variation in Vision in Normal Light | | | | | |
| Preop | 85% | 11% | 4% | <1% | <1% |
| Month 6 | 70% | 19% | 9% | 1% | 1% |
| Month 9 | 71% | 17% | 8% | 3% | 1% |
| Month 12 | 70% | 22% | 6% | 2% | 1% |
| Variation in Vision in Dim Light | | | | | |
| Preop | 75% | 14% | 8% | 1% | 1% |
| Month 6 | 54% | 26% | 13% | 5% | 1% |
| Month 9 | 60% | 19% | 12% | 5% | 3% |
| Month 12 | 57% | 25% | 11% | 4% | 3% |
Page 28 of 30
{28}
Table 21
Subject Symptoms
All Eyes Treated
(Continued)
| | None | Mild | Moderate | Marked | Very Severe |
| --- | --- | --- | --- | --- | --- |
| Night Driving Vision Problems | | | | | |
| Preop | 64% | 19% | 12% | 2% | 2% |
| Month 6 | 55% | 24% | 12% | 6% | 4% |
| Month 9 | 59% | 23% | 7% | 6% | 4% |
| Month 12 | 60% | 24% | 7% | 5% | 4% |
| Other Symptoms | | | | | |
| Preop | 96% | 1% | 2% | 1% | 0% |
| Month 6 | 96% | 2% | 1% | <1% | 1% |
| Month 9 | 97% | 2% | 1% | 0% | <1% |
| Month 12 | 96% | 1% | 1% | 1% | <1% |
NOTE: At the 12 month interval, ≥ 5% of patients reported a postoperative increase in moderate to marked ratings for the following symptoms: glare, halos, fluctuation of vision, and variation in vision in dim light. There was no significant increase (≥ 5%) in symptoms with very severe rating.
## XI. CONCLUSIONS DRAWN FROM THE STUDIES
The data in this application support reasonable assurance of the safety and efficacy of this device when used in accordance with the indications for use.
## XII. PANEL RECOMMENDATION
On November 20, 2001, the Ophthalmic Devices Advisory Panel recommended that the premarket approval application for the Refracic ViewPoint™ CK™ System for the treatment of hyperopia be considered approvable with conditions. The conditions recommended by the panel were to:
1. Revise the indications for use statement as follows:
- Conductive keratoplasty treatment is for the temporary reduction of spherical hyperopia in the range of:
+0.75 to +3.25 Diopters (D) of cycloplegic spherical hyperopia
-0.75 D or less of refractive astigmatism
+0.75 to +3.00 D cycloplegic spherical equivalent
- In patients with ≤ 0.50 D difference between preoperative manifest and cycloplegic refractions.
- In patients 40 years of age or older.
2. Revise the labeling.
3. Continue the clinical study out to 24 months and submit the data to FDA for review as a post market study.
Page 29 of 30
{29}
Page 30 of 30
## XIII. CDRH DECISION
Following the panel meeting on November 30, 2001, FDA did not issue a deficiency letter to Refractec, Inc., but worked interactively with Refractec regarding the remaining issues. Generally, FDA agreed with the Panel's recommendations, and Refractec agreed to continue follow-up of subjects in their clinical study per the protocol out to the 24-month examination. Refractec submitted responses that adequately addressed all of FDA's concerns and labeling changes.
The applicant’s manufacturing facilities were inspected and found to be in compliance with the Quality Systems Regulation (21 CFR 820). CDRH issued an approval order on April 11, 2002.
## XIV. APPROVAL SPECIFICATIONS
- Postapproval Requirements and Restrictions: see Approval Order.
- Hazards to Health from Use of the Device: see Indications, Contraindications, Warnings, Precautions, and Adverse Events in the labeling.
- Directions for Use: see labeling.
