European clinical evaluation: Use of Intacs for the treatment of keratoconus

Transcription

1 J CATARACT REFRACT SURG - VOL 32, MAY 2006 European clinical evaluation: Use of Intacs for the treatment of keraconus Joseph Colin, MD PURPOSE: To evaluate the safety and efficacy of Intacs inserts in keraconic eyes alter corneal shape and refractive power and stabilize the progression of corneal ectasia. SETTING: Service d Ophtalmologie, Bordeaux, France. METHODS: In this prospective study, 57 eyes with clear central corneas that were diagnosed with keraconus and contact lens inlerant were followed for up 1 year. The primary objectives were assess the safety of Intacs and the visual outcomes by measuring uncorrected visual acuity (UCVA), best corrected visual acuity, manifest refraction spherical equivalent, kerametry, intraocular pressure (IOP), pachymetry, and patient satisfaction. The stability of the refraction, kerametry, and visual acuity measurements was also assessed. RESULTS: At the 6-month examination, 78% of patients showed improvement of 2 lines or more in UCVA (P<.001). Best corrected visual acuity of 20/40 or better improved from 53% of patients preoperatively 74% of patients (P%.033). Manifest refraction spherical equivalent improved 3.1 G 2.5 diopters (D) (P<.001) compared with the preoperative examination. Kerametry decreased a mean of ÿ4.3 G 2.8 D from the preoperative readings (P%.002). These changes appeared be stable over time. At 6 months, there were no adverse events, no clinically significant increase in IOP, and no decrease in central corneal thickness. In 7 of 57 eyes (12%), the Intacs were removed due dissatisfaction with visual sympms. There were no adverse effects or complications associated with the Intacs removal. CONCLUSIONS: Intacs were safe and effective for treating keraconus. All patients demonstrated improved objective visual outcomes; functional vision was resred in most patients. Intacs were removed without permanent sequelae. J Cataract Refract Surg 2006; 32: Q 2006 ASCRS and ESCRS Keraconus is a progressive, noninflammary, bilateral corneal dystrophy that is characterized by paracentral cone-like steepening of the cornea and corneal ectasia. The progressive thinning and subsequent anterior bulging of the cornea lead severe astigmatism and central scarring (corneal opacities), producing visual disrtion, Accepted for publication February 17, From the Service d Ophtalmologie, Bordeaux, France. Presented at ASCRS Symposium on Cataract, IOL and Refractive Surgery, San Diego, California, USA, May The author has no financial or proprietary interest in any material or method mentioned. Reprint requests Joseph Colin, MD, Chef du Service d Ophtalmologie, Centre Hospitalier Universitaire Pellegrin Place Amélie Raba-Léon, Bordeaux, Cedex, France. joseph.colin@chu-bordeaux.fr. increased sensitivity light, and an associated reduction in best corrected visual acuity (BCVA). 1,2 The patients are often fitted with rigid gas-permeable contact lenses improve the quality of vision. Although spectacles and contact lenses can be successful in treating the early stages of the disease, a corneal transplant procedure is the only method of treatment currently available when these modalities are no longer successful. 3 5 In selected cases, the cornea is still transparent. These relatively young patients may be reluctant pursue penetrating keraplasty and seek a less invasive intervention improve BCVA and/or uncorrected visual acuity (UCVA). Many kerarefractive options for the treatment of keraconus (radial keramy [RK], astigmatic keramy, phorefractive keratecmy [PRK], and laser in situ keramileusis [LASIK]) have been reported weaken the structural integrity of the cornea. These procedures have not gained popularity in treating keraconus because of reported Q 2006 ASCRS and ESCRS Published by Elsevier Inc /06/$-see front matter doi: /j.jcrs

2 complications, corneal instability, and poor predictability. 6 9 Intacs inserts are currently approved in the United States by the U.S. Food and Drug Administration (FDA) and in Europe by the Communauté Européene for use in the reduction or elimination of myopia and astigmatism. They have been reported be an effective modality for the treatment of keraconus and stabilize ectasia resulting from kerarefractive surgery or other causes Intacs were first used for the correction of low myopia They act as passive spacing elements that shorten the arc length of the anterior corneal surface, flattening the central cornea. 18,19 The biomechanical effect of rings should be greater in keraconic eyes, which have thinner corneas. Now supplied by Addition Technology, Intacs are delivered in boxes containing 2 segments of the same thickness. In Europe, Intacs corneal rings are available in 11 sizes ranging from mm. In the United States, the rings are available in 5 sizes from 0.25 mm 0.35 mm. The major objective is reshape keraconic corneas a more regular corneal surface and resre contact lens lerance. Intacs are placed within the cornea lift the inferior or superior ectasia and flatten the soft keraconic corneal tissue decrease the asymmetric astigmatism induced by keraconus without removing corneal tissue or invading the central optical zone. The rings may be explanted if needed. Several reports describe the use of Intacs for the treatment of ectatic disease such as corneal thinning after LASIK or other kerarefractive surgical procedures Treatment with Intacs will not eliminate the progression of keraconus, but it may delay a corneal transplant procedure and may slow the progression of the corneal thinning associated with the disease. Results from preliminary studies indicate that Intacs seem allow better quality of vision in patients with advanced keraconus, may permit refitting these patients with contact lenses, and may delay or eliminate the need for a corneal transplant procedure. 23 PATIENTS AND METHODS A prospective clinical investigation was conducted at 4 European clinical sites evaluate the safety and effectiveness of Intacs for the treatment of keraconus. Additional patients were enrolled at a fifth site by the chief clinical investigar (Table 1). This report contains data from 57 eyes that were implanted with Intacs and followed for up 12 months. The study was designed identify ocular complications and adverse effects that occurred after implantation of Intacs in keraconic patients and evaluate the visual acuity outcome and the stability of treatment for up 1 year posperatively. The main objective of the study was assess posperative visual outcomes relative the patients baseline measurements. Secondary study objectives of reduction in corneal ectasia and increased patient Table 1. Study investigars and site locations. Site Principal Investigar Site location 1 Joseph Colin* CHRU MORVAN, Centre Hospitalier Regional et Universitaire De Brest, Cedex, France 2 Emanuel Rosen Rosen Eye Surgery Centre, Alexandra Hospital Vicria Park, Manchester, United Kingdom 3 Thomas Neuhann ALZ Augenklinik, Munich, Germany 4 Carlo Lovisolo Via Formentini, Milano, Italy 5 Joseph Colin* Bordeaux University Hospital, Hospital Pellegrin, Bordeaux, France *Chief clinical investigar for this study satisfaction were assessed in the same fashion. The posperative measurements were compared with the preoperative values for each treated eye. Five Intacs thicknessesd0.250 mm, mm, mm, mm, and mmdwere available for use in this study. The clinical evaluation was conducted between September 1999 and March The purpose of this study was assess the effects of implanting Intacs inserts, identical those commercially available correct myopia, in the corneal stroma of patients with keraconus (moderate severe) and a clear cornea. The principle of the procedure is flatten and reshape the cornea deformed by keraconus. One or 2 segments of the same or a different thickness were selected reduce the asymmetric astigmatism responsible for the patients impaired visual acuity. Assessment Criteria Primary assessment criteria were evaluation of the safety of the device for the treatment of patients with keraconus (stage I or stage II), maintenance of BCVA, improvement in UCVA, reduction in manifest refraction spherical equivalent (MRSE), and reduction in asymmetric astigmatism. Secondary assessment criteria were evaluation of the effect of Intacs placement for treatment of corneal ectasia and determination of patient satisfaction after the Intacs procedure. Surgical Procedure Treatment nomograms, described in Tables 2 and 3, were used determine the appropriate Intacs placement and thicknesses implant in the keraconic patients corneas. The nomograms were based on the patients preoperative spherical equivalent, the location of the cone, and the asymmetric astigmatism induced by the keraconus. The Intacs procedure can be performed under pical anesthesia, oral or intravenous conscious sedation with pical anesthesia, or general anesthesia. To reduce the irregular astigmatism induced by keraconus and reduce the associated myopia, 1 or 2 inserts ranging from mm mm can be implanted in the inferior tunnel and the superior tunnel flatten the affected area of bulging cornea. The geometric center of the 748 J CATARACT REFRACT SURG - VOL 32, MAY 2006

3 Table 2. Recommended placement nomogram for keraconus. Type of Keraconus Asymmetrical cone Global cone Central cone cornea was identified using the 11 mm zone marker, and the center was marked using a Sinskey hook. If the right eye was be implanted, the incision mark of the zone marker was aligned with the 9-o clock position 1.0 mm from the limbus. If the left eye was be implanted, the incision mark was aligned with the 3-o clock position 1.0 mm from the limbus. A 1.2 mm long radial incision was created approximately 70% of the corneal thickness at the incision site. The intrastromal tunnels were initiated using a pocketing hook (formerly a stromal spreader). A glide blade was introduced in the incision assess incision length and verify the adequacy of the pocket. The vacuum centering guide (VCG) was placed along with the procedure marker on the corneal surface. The VCG and procedure marker were aligned with the geometric center of the cornea. The KV 2000 vacuum system was started on the low setting and ramped up the high setting. The CCW and CW dissecrs (corneal separars) were used create the intrastromal tunnels in the desired directions, and then the KV 2000 vacuum system was turned off. The VCG was removed, and the desired insert thickness was implanted in the tunnels. The wound was closed with a 10-0 or 11-0 nylon suture with the knot buried. Antibiotic/corticosteroid eyedrops were administered the patient posperatively. Patient Follow-up Intacs Product Configuration 2 Intacs inserts of different thicknesses (1 thinner Intacs insert placed superiorly, 1 thicker Intacs insert placed inferiorly) 2 Intacs inserts of the same thickness (1 Intacs insert placed superiorly, 1 Intacs insert placed inferiorly) 2 Intacs inserts of the same thickness (1 Intacs insert placed superiorly, 1 Intacs insert placed inferiorly) Patients were examined 1 and 7 days and 1, 3, 6 and 12 months. The following parameters were evaluated preoperatively and at selected follow-up visits: intraocular pressure (IOP), pachymetry, slitlamp examination of the anterior segment, UCVA and BCVA, MRSE, kerametry, and corneal pography. Additionally, patients completed a patient comment checklist preoperatively and at each follow-up examination. This information was used determine the patients perception of the success of the Intacs procedure and record their subjective feedback. Patients were considered have successfully completed the study after the completion of 12 months of follow-up. A patient was discontinued from the study if there was reason remove Intacs or if there was an operative or posperative adverse event. When patients expressed dissatisfaction with their outcome, the Intacs were removed. Postremoval follow-up was conducted for the patients, and they left than the study. RESULTS Of the 59 eyes enrolled, Intacs were successfully implanted in 58 eyes. The remaining enrolled eye did not have supporting documentation confirm whether implantation had been performed. One of the 58 implanted eyes was lost follow-up after the 1-month examination and was therefore not included in the analysis. Fifty-seven eyes were followed for evaluation, and 34 eyes were evaluated at the 6-month examination. No adverse events were reported intraoperatively. All patients presented with moderate severe keraconus and had clear central corneas. Preoperative UCVA ranged from 20/32 counting fingers with a mean UCVA slightly worse than 20/200 (logmarz1.06). The preoperative BCVA ranged from 20/20 20/200 with a mean of 20/50 (logmarz0.40). Patients had a mean spherical equivalent (SE) of ÿ4.6 diopters (D) G 3.5 with a mean value for preoperative manifest refraction cylinder of 4.4 G 2.4 D. The mean kerametry SE was 49.7 G 4.9 D. Preoperatively, the mean IOP in the operative eye was 13.2 G 1.8 mm Hg (range mm Hg) and the mean central pachymetry reading of all patients was 487 G 79.1 mm. Table 4 provides the preoperative data for all that were evaluated eyes. Posperative Observations, Complications, and Adverse Events Ocular observations at all posperative examinations were minor and were not considered clinically significant by the investigars. There were no reports of safetyrelated findings including ocular infection, extrusion of the insert, or stromal thinning over the insert at any posperative examination. The most commonly reported posperative observations were intrastromal deposits on or near the inserts and haze in the incision area. These observations Table 3. Recommended thickness nomogram for keraconus. Type of cone Preoperative SE!3.00 D Preoperative SE O3.00 D Asymmetric mm/0.300 mm mm/0.350 mm Moderate asymmetry mm/0.400 mm mm/0.450 mm High asymmetry mm/0.400 mm mm/0.450 mm Global mm/0.400 mm mm/0.450 mm Central mm/0.400 mm mm/0.450 mm SE Z spherical equivalent J CATARACT REFRACT SURG - VOL 32, MAY

4 Table 4. Preoperative variables for enrolled patient eyes. Preoperative Parameter N Mean G SD Uncorrected visual acuity* G 0.33 Best corrected visual acuity* G 0.24 Manifest refraction G 2.4 cylinder (D) Manifest refraction spherical 57 ÿ4.6 G 3.5 equivalent (D) Kerametry spherical G 4.9 equivalent (D) Intraocular pressure (mm Hg) G 1.8 Central pachymetry (mm) G 79.1 *LogMAR scores were also reported during the U.S. clinical trials for the myopia indication. The only other ocular observations were patient-reported visual sympms of fluctuating vision, glare, diplopia, and difficulty with day and/or night vision. There was a general trend ward a reduction in visual sympms over time, which was also observed for the myopia indication. At the 6-month examination, 9 patients reported having moderate or severe visual sympms consisting of discomfort (nz1), itching (nz1), burning (nz1), phophobia (nz1), difficulty with night vision (nz1), glare (nz3), and fluctuating vision (nz1). Dissatisfaction with visual sympms was the reason for removal of the inserts from 7 eyes (12%). A patient was considered as being explanted when the insert was completely removed. Intraocular Pressure Intraocular pressure was measured for patients at the 4 sites participating in the clinical study; however, it was not recorded at site 5. Mean IOP measurements for the implanted eyes at all posperative examinations were similar the preoperative values. Table 5 provides the IOP change from the preoperative baseline. Pachymetry Central pachymetry measurements were taken preoperatively and at the scheduled posperative follow-up Table 5. Change in IOP from the preoperative examination. IOP 1 Day 7 Days 1 Month 3 Months 6 Months 12 Months N Mean ÿ0.4 ÿ1.3 ÿ1.0 ÿ ÿ0.7 SD Min ÿ6 ÿ6 ÿ5 ÿ4 ÿ4 ÿ6 Max N Z number of eyes; SD Z standard deviation; IOP Z Intraocular pressure; Source: IOP.SAS (21 August 2003) examinations. There were no statistically significant changes in central pachymetry over the 12-month posperative period (PO.085). Best Corrected Visual Acuity The BCVA data from the study eyes at the preoperative and 3 and 6 month posperative examinations are shown in Table 6. Thirty eyes (53%) had a BCVA of 20/40 or better at the preoperative examination. This increased 71% (22/31) and 74% (25/34) at 3 months and 6 months, respectively. There was a statistically significant (P%.033) improvement in BCVA between the 1- and 6-month examinations. The change in BCVA lines gained or lost at 6 months compared with the preoperative baseline is presented in Table 7 and Figure 1. There was a significant improvement (P!.001) in BCVA between the preoperative and 6-month examinations. Of the 34 eyes evaluated at the 6 months, 21 of 34 (62%) experienced a gain of 2 8 lines of BCVA. Eleven of 34 eyes (32%) experienced no change in BCVA (defined as G 1 line of acuity change), and 2 eyes had a loss of 2 lines of BCVA. Posperative BCVA stability is summarized in Table 8 as the number and percentage of eyes with a BCVA within 2 lines (0.2 logmar) of the previous examination. The percentage of eyes with a stable BCVA exceeded 84% for all intervals after 1 month. Uncorrected Visual Acuity Table 9 provides the UCVA for all patients at the preoperative and 3- and 6-month examinations, and Figure 2 shows the change in UCVA between the posperative Table 6. Best corrected visual acuity over time. Preoperative 3 Months 6 Months BCVA n/n % n/n % n/n % 20/20 or better 3/57 5 1/31 3 2/ /25 or better 7/ / / /32 or better 15/ / / /40 or better 30/ / / /50 or better 36/ / / /63 20/100 15/ / / /125 20/200 6/ /31 0 2/ /250 20/400 0/57 0 0/31 0 0/34 0 O20/400 20/600 0/57 0 0/31 0 0/ /800 0/57 0 0/31 0 0/34 0 Counting fingers 0/57 0 0/31 0 0/34 0 Total evaluated 57 d 31 d 34 d Not reported 0 d 0 d 0 d Total evaluable 57 d 31 d 34 d Source: FDA, June 5, J CATARACT REFRACT SURG - VOL 32, MAY 2006

5 print & web 4C=FPO Table 7. Summary of change in BCVA from preoperative value (n Z 34) at 6 months. BCVA n/n % Gain of 6 8 lines 1/34 3 Gain of 2 5 lines 20/34 59 No change 11/34 32 Loss of R2 lines 2/34 6 and 6-month examinations. Only 4% (2/53) of eyes had a UCVA of 20/40 or better at the preoperative examination. At the 3- and 6-month, 17% (5/29) and 24% (8/34) of patients respectively, had a UCVA of 20/40 or better. There was a statistically significant (P!.001) improvement in UCVA through the 6-month examination. Table 10 provides the posperative UCVA stability as the number and percentage of eyes with an UCVA within 2 lines (0.2 log- MAR) of their previous examination. Over 78% of eyes had a stable UCVA between consecutive examinations from 1 month through 6 months. Manifest Refraction Spherical Equivalent Table 11 shows the improvement in MRSE, which was a mean of 1.7 G 2.8 D, 2.8 G 3.0 D, and 3.1 G 2.5 D at the 1-, 3-, and 6-month examinations, respectively. There was a statistically significant (P!.001) change in MRSE at 6 months, as compared with the preoperative examination. Table 12 summarizes the posperative manifest refraction stability between consecutive examinations as the number and percentage of eyes within G0.5 D and G1.0 D of the previous examination. Over 50% of the eyes had a manifest refraction that was stable within G0.5 D of the previous examination through 6 months. Seventy-five percent of eyes had a stable manifest refraction at 6 months that was within G1.0 D of the 3-month result. 100% 80% 60% 40% 20% 0% Gain 2 or More Lines No Change +/- 1 Line Loss 2 or More Lines Figure 1. Change in BCVA from the preoperative evaluation the 6-month evaluation. Table 8. Stability of BCVA. BCVA Within 2 lines Manifest Refraction Cylinder The absolute value of the manifest refraction cylinder was used as a measure of the change in the refractive astigmatism. The change in manifest refraction cylinder from the preoperative baseline over time is presented in Table 13. The cylinder values at the 3- and 6-month examinations were statistically significantly less than the preoperative measurements (P!.001). Kerametry 7 Days 1 month 1 Month 3 months 3 Months 6 months 6 Months 12 months 26/32 (81) 24/27 (89) 16/19 (84) 8/9 (89) BCVA Z best corrected visual acuity Source: BSCVAStability.SAS (01 August 2005) The mean kerametry reading was 49.7 G 4.9 D at the preoperative examination. At 1 month after implantation, the mean kerametry reading had decreased 46.2 G 3.9 D. The month 3 and month 6 kerametry readings of 46.5 G 4.3 D and 46.0 G 3.5 D, respectively, were similar the month 1 reading. Table 14 summarizes the mean change in kerametry readings. The kerametry readings indicate that the central cornea curvatures were significantly (P%.002) flattened at month 3 and month 6, as compared with the preoperative baseline. Posperative kerametry stability is shown in Table 15. Stability is Table 9. Uncorrected visual acuity over time. Preoperative 3 Months 6 Months UCVA n/n % n/n % n/n % 20/20 or better 0/53 0 0/29 0 0/ /25 or better 0/53 0 0/29 0 1/ /32 or better 1/53 2 1/29 3 7/ /40 or better 2/53 4 5/ / /50 or better 2/53 4 9/ / /63 20/100 10/ / / /125 20/200 17/ / / /250 20/400 21/ / /34 9 O20/400 20/600 2/53 4 0/29 0 0/ /800 0/53 0 0/29 0 0/34 0 Counting fingers 1/53 2 0/29 0 0/34 0 Total evaluated 53 d 29 d 34 d Not reported 4 d 2 d 2 d Total evaluable 57 d 31 d 34 d Source: FDA, June 5, 2003 J CATARACT REFRACT SURG - VOL 32, MAY

6 print & web 4C=FPO 100% 80% 60% 40% 20% 0% Gain 2 or More Lines computed as the change in kerametry between consecutive examinations and is summarized as the number and percent of eyes within 0.5 D and 1.0 D of the previous examination. With the exception of the percentage of eyes at month 1 within 1.0 D of the day 7 examination, stability of the kerametry readings improved through the month 6 examination. Subjective Assessment No Change +/- 1 Line Loss 2 or More Lines Figure 2. Change in UCVA from the preoperative evaluation the 6-month evaluation. Table 10. Stability of UCVA. UCVA Within 2 lines 7 Days 1 month 1 Month 3 months 3 Months 6 months 6 Months 12 months 24/36 (67%) 21/27 (78%) 14/18 (78%) 3/9 (33%) UCVA Z uncorrected visual acuity Source: UCVAStability.SAS (01 August 2005) At each scheduled examination, patients were asked a series of questions from the patient comment checklist record each patient s subjective assessment of their visual outcome after the Intacs procedure. Patients were asked a series of questions about their treatment eye and directed rate any sympms as none, mild, moderate, or severe and whether the sympms occurred under day or night conditions. The patients were questioned about the presence of the following visual sympms: discomfort, itching, burning, foreign-body sensation, phophobia, fluctuating vision, difficulty with night vision, double images, glare, halos, or other types of visual sympms. There was a trend ward improvement in the patientreported visual sympms over time. Table 16 provides a summary of the patients subjective responses over time. There were 31 reports of visual sympms at the preoperative examination compared with 21 reports and 9 reports at the month 3-month and 6-month examinations, respectively. Patients were asked rate the quality of their vision in the treatment eye as being excellent, good, fair, or poor preoperatively and at the scheduled posperative examinations. Table 17 provides a summary of the patients quality of vision at the 6-month examination compared with the preoperative baseline. Preoperatively, 27 of 39 eyes (69.2%) had poor quality of vision, 8 of 39 (20.5%) had fair quality of vision, and 4 of 39 (10.2%) had a quality of vision that was good. No patient reported that their quality of vision was excellent at the preoperative examination. At the 6-month examination, 5 of 21 eyes (23.8%) had poor quality of vision, 6 of 21 (28.6%) had fair quality of vision, 8 of 21 (38.1%) had good quality of vision, and 2 of 21 (9.5%) had excellent quality of vision. There was a statistically significant (P!.001) improvement in the patient-reported quality of vision at the month 6 examination. DISCUSSION The goal for the use of Intacs treat patients with keraconus is defer the need for a corneal transplant and resre contact lens lerance. Intacs provide structural integrity and support the central optical zone. The inserts are placed within the cornea lift the inferior or superior ectasia and flatten the keraconic corneal tissue decrease the asymmetric or irregular astigmatism that is induced by the keraconus disease process and address the patients varying degrees of myopia. Intacs are intended reshape the keraconic cornea, by using 2 inserts of symmetric or asymmetric sizes create a more regularly Table 11. Change in MRSE (D) from the preoperative examination. MRSE 1 Day 7 Days 1 Month 3 Months 6 Months 12 Months N Mean SD Min ÿ3.500 ÿ3.750 ÿ6.000 ÿ6.000 ÿ1.625 ÿ1.000 Max MRSE Z manifest refraction spherical equivalent Source: MRSE.SAS (02 September 2003) 752 J CATARACT REFRACT SURG - VOL 32, MAY 2006

7 Table 12. Stability of MRSE. MRSE 7 Days 1 month 1 Month 3 months 3 Months 6 months 6 Months 12 months Within G 0.5 D 17/33 (52) 14/26 (54) 8/16 (50) 1/7 (14) Within G 1.0 D 25/33 (76) 15/26 (58) 12/16 (75) 2/7 (29) Source: MRStability.SAS (01 August 2005) Table 13. Manifest refraction cylinder change (D) from the preoperative examination. Manifest Refraction Cylinder 1 Day 7 Days 1 Month 3 Months 6 Months 12 Months N Mean ÿ1.08 ÿ1.58 ÿ1.67 ÿ2.00 ÿ1.52 ÿ2.89 SD Min ÿ4.00 ÿ7.00 ÿ7.00 ÿ5.00 ÿ4.25 ÿ7.00 Max ÿ0.25 Source: Cyl.SAS (28 August 2003) shaped corneal surface. It is believed that the ability create a more regularly shaped corneal surface should allow keraconus patients be successfully refitted with contact lenses, if required, improve their functional vision and defer or potentially eliminate the need for a corneal transplant. Although there are other subtractive and additive refractive techniques for treating keraconus, none has been thoroughly studied. One of the more logical methods of treatment is reinforce the keraconic cornea using an additive procedure, such as placing Intacs in the cornea. This stands in stark contrast other procedures, which weaken the structural integrity of the cornea through the use of incisions (RK) or ablation (PRK LASIK). The use of Intacs for patients with keraconus is considered be a successful treatment modality The investigars performed the Intacs procedure under pical anesthesia, oral or intravenous conscious sedation with pical anesthesia, or general anesthesia, as determined by the preference of the specific physician and patient. The Intacs procedure was performed in 20 G 7 minutes in this study. It can typically be performed in an outpatient setting with the surgical instrumentation as used for the Intacs myopia procedure. The safety profile for Intacs for the treatment of myopia is well established, and they have been safely and effectively used for the correction of myopia over the past 10 years. There were no adverse events or operative complications reported in any of the 57 eyes implanted with Intacs during this clinical trial. Additionally, there were no clinically significant or unanticipated product-related posperative ocular observations at any examination up 12 months. Posperatively, the slitlamp observations consisted of minimal positive findings for corneal staining and conjunctival injection at mainly the 1-day examination. The only significant slitlamp finding, beyond the typical posperative recovery period, was a finding of severe conjunctival injection at a 7-month interim examination, when the patient reported a foreign-body sensation after he got sand in his eye. The slitlamp observations reported for this study were similar those reported in the U.S. phase 2 and 3 trials for the myopia indication. There were no posperative reports of infection at any time point, and IOP measurements in the treated eyes were stable over the course of the study. Additionally, there was no indication of corneal thinning over the inserts as Table 14. Kerametry spherical equivalent stability change from the preoperative examination. Kerametry 1 Day 7 Days 1 Month 3 Months 6 Months 12 Months N Mean ÿ2.9 ÿ2.9 ÿ2.3 ÿ2.2 ÿ4.3 ÿ4.3 SD Min ÿ10.0 ÿ26.8 ÿ8.6 ÿ12.8 ÿ9.6 ÿ8.5 Max ÿ1.0 SE Z spherical equivalent Source: Kerametry.SAS (23 July 2003) J CATARACT REFRACT SURG - VOL 32, MAY

8 Table 15. Kerametry stability SE. Kerametry SE 7 Days 1 month 1 Month 3 months 3 Months 6 months 6 Months 12 months Within G 0.5 D 12/34 (35) 11/26 (42) 8/15 (53) 3/8 (38) Within G 1.0 D 21/34 (62) 15/26 (58) 10/15 (67) 3/8 (38) SE Z spherical equivalent Source: KStability.SAS (01 August 2005) determined by the central pachymetry measurements and slitlamp examination performed at each examination through the 12-month time point. Seven of the 57 eyes had visual sympms that resulted in the patients request for removal of the inserts. The reported visual sympms included fluctuating vision, poor night vision, glare, and phophobia. There were 3 surgical interventions performed, in which 1 of the 2 Intacs inserts originally implanted was removed, and these interventions all resulted in satisfacry visual outcomes for the patients. The 4 eyes that had complete removal of the inserts were discontinued, and these patients subsequently exited from the study; those eyes that experienced the removal of only 1 of the 2 original inserts were followed in the clinical study. The removal data from this clinical study demonstrate that the inserts used for the treatment of keraconus can be successfully removed, as the inserts implanted for the correction of myopia. The data presented in this report provide summaries of measurements of visual outcomes and statistical comparisons of preoperative and posperative values. The key results from this study are summarized below: Best corrected visual acuity improved from 53% of eyes with 20/40 or better at the preoperative examination 74% at the 6-month examination. Also, 62% of eyes experienced an improvement of 2 or more lines of BCVA (range 2 8 lines) at the 6-month examination compared with the preoperative baseline. Only 2 eyes lost 2 lines of BCVA between the preoperative and 6-month examinations. These data support that BCVA is not only maintained in most keraconic eyes, but also significantly improved after the Intacs procedure. Preoperatively, just 4% of uncorrected eyes could see 20/40 or better, whereas 24% of uncorrected eyes could see 20/40 or better at 6-months. At the 6-month examination, 78% of the eyes experienced a gain of 2 or more lines of UCVA (range 2 11 lines) compared with their preoperative baseline. There was marked improvement in UCVA between the preoperative and 6-month examinations. Seventy-eight percent (78%) of eyes had a stable UCVA between consecutive examinations from 1 month 6 months. The mean MRSE also improved from the preoperative baseline of ÿ4.6 G 3.5 D ÿ2.1 G 2.8 D at the 6-month examination. Seventy-five percent of eyes had a stable manifest refraction at 6-months that was within 1.0 D of the 3-month result. The refractive astigmatism was reduced by 2.94 G 1.64 D at the 6-month examination. Table 16. Patient subjective responses over time. Preoperative (n Z 39) 3 Months (n Z 28) 6 Months (n Z 23) 12 Months (n Z 10) Moderate/Severe Sympms Moderate/Severe Sympms Moderate/Severe Sympms Moderate/Severe Sympms Visual Sympms Frequency % Frequency % Frequency % Frequency % Discomfort Itching Burning Foreign-body sensation Phophobia Fluctuating vision Difficulty with night vision Double images Glare Halos Other J CATARACT REFRACT SURG - VOL 32, MAY 2006

9 Table 17. Change in quality of vision between the preoperative and 6-month examinations. Preoperative 6 Months Quality of Vision n/n % n/n % Poor 27/ / Fair 8/ / Good 4/ / Excellent 0/39 0 2/ The kerametry readings also reflected the ability of the inserts flatten the cornea and reduce corneal surface abnormalities brought on by the progression of keraconus. The kerametry readings seemed stable from 1 month through 6 months. There was a trend ward improvement in patientreported visual sympms over time. All of the reported visual sympms from this study were similar those reported with Intacs for myopia. The patients were also asked rate the quality of vision in the treatment eye(s). Overall, 76% of patients (16/21) reported an improvement in their quality of vision after the Intacs procedure. CONCLUSION This clinical study demonstrates that Intacs are a viable option for the treatment of patients with moderate severe keraconus who are contact lens inlerant. Posperatively, the keraconus patients had a significant improvement in visual acuity and reduction in corneal steepening and astigmatism. No surgical complications, adverse events, or clinically significant posperative ocular complications related the Intacs were noted during this study. The clinical findings of this study are similar those previously reported as part of the U.S. clinical trials for the FDA-approved myopia indication. Intacs are a logical addition the stepwise treatment of keraconus for improvement of functional vision. In a significant number of patients treated date, Intacs have deferred the need for corneal transplantation. Intacs induce substantial changes in the central cornea without removing tissue. Given the central thinning inherent in keraconus, the use of Intacs for this proposed therapeutic indication seems be an ideal application of the technology. An added benefit of using Intacs treat patients with keraconus is that if the outcome is not acceptable due visual sympms, continued progression of the disease, and/or decreased visual acuity, the inserts can be removed and corneal transplantation can be performed. REFERENCES 1. Rabinowitz YS. Keraconus. Surv Ophthalmol 1998; 42: Brierly SC, Izquierdo L Jr, Mannis MJ. Penetrating keraplasty for keraconus. Cornea 2000; 19: Coombes AGA, Kirwan JF, Rostron CK. Deep lamellar keraplasty with lyophilised tissue in the management of keraconus. Br J Ophthalmol 2001; 85: Haugen OH, Høvding G, Eide GE, Bertelsen T. Corneal grafting for keraconus in mentally retarded patients. Acta Ophthalmol Scand 2001; 79: Lahners WJ, Russell B, Grossniklaus HE, Stulting RD. Keralysis following excimer laser photherapeutic keratecmy in a patient with keraconus. J Refract Surg 2001; 17: Mortensen J, Öhrström A. Excimer laser phorefractive keratecmy for treatment of keraconus. J Refract Corneal Surg 1994; 10: Colin J, Cochener B, Bobo C. Myopic phorefractive keratecmy in eyes with atypical inferior corneal steepening. J Cataract Refract Surg 1996; 22: Moodaley L, Lin C, Woodward EG, et al. Excimer laser superficial keratecmy for proud nebulae in keraconus. Br J Ophthalmol 1994; 78: Kremer I, Shochot Y, Kaplan A, Blumenthal M. Three year results of phoastigmatic refractive keratecmy for mild and atypical keraconus. J Cataract Refract Surg 1998; 24: Colin J, Cochener B, Savary G, Malet F. Correcting keraconus with intracorneal rings. J Cataract Refract Surg 2000; 26: Chou B, Boxer Wachler BS. Intacs for a keracone: a promising new option? Opt J Rev Opm 2000; 137: Boxer Wachler BS, Christie JP, Chandra NS, et al. Intacs for keraconus. Ophthalmology 2003; 110: ; errata p Schanzlin DJ, Asbell PA, Burris TE, Durrie DS. The intrastromal corneal ring segments; phase II results for correction of myopia. Ophthalmology 1997; 104: Nosé W, Neves RA, Burris TE, et al. Intrastromal corneal ring: 12-month sighted myopic eyes. J Refract Surg 1996; 12: Fleming JF, Wan WL, Schanzlin D. The theory of corneal curvature change with the intrastromal corneal ring. CLAO J 1989; 2: Cochener B, Le Floch G, Colin J. Les anneaux intracorneéns pour la correction des faibles myopie. J Fr Ophtalmol 1998; 21: Asbell PA, Uçakhan ÖÖ, Durrie DS, Lindstrom RL. Adjustability of refractive effect for corneal ring segments. J Refract Surg 1999; 15: Burris TE, Ayer CT, Evensen DA, Davenport JM. Effects of instrastromal corneal ring size and thickness on corneal flattening in human eyes. Refract Corneal Surg 1991; 7: Burris TE, Baker PC, Ayer CT, et al. Flattening of central corneal curvature with intrastromal corneal rings of increasing thickness: an eyebank eye study. J Cataract Refract Surg 1993; 19: Gomez L, Chayet A. Laser in situ keramileusis results after intrastromal corneal ring segments (Intacs). Ophthalmology 2001; 108: Kymionis GD, Siganos CS, Kounis G, et al. Management of post-lasik corneal ectasia with Intacs inserts: one-year results. Arch Ophthalmol 2003; 121: Lovisolo CF, Fleming JF. Intracorneal ring segments for iatrogenic keratectasia after laser in situ keramileusis or phorefractive surgery. J Refract Surg 2002; 18: Colin J, Velou S. Utilization of refractive surgery technology in keraconus and corneal transplants. Curr Opin Ophthalmol 2002; 13: J CATARACT REFRACT SURG - VOL 32, MAY