Bozkurt Sener

Multicenter study of the Artisan phakic intraocular lens.

PURPOSE To assess the Artisan intraocular lens to correct myopia in phakic eyes. SETTING European multicenter study sponsored by Ophtec BV, Groningen, The Netherlands. METHODS In this prospective multicenter clinical study, the Artisan lens was implanted in 518 eyes between September 1991 and October 1999. The power of the lenses ranged from -5.0 to -20.0 diopters (D). Follow-up examinations were performed at 6 months and 1, 2, and 3 years. Follow-up ranged from 6 months (n = 454) to 3 years (n = 249). The preoperative uncorrected visual acuity (UCVA) was not recorded but was estimated to be worse than 0.1. The preoperative mean best spectacle-corrected visual acuity (BSCVA) was 0.67 +/- 0.26 (SD). Endothelial cell counts were done at 6 months and 1, 2, and 3 years in a subgroup of 129 eyes. RESULTS A UCVA of 20/40 or better was observed in 76.8% of eyes regardless of the postoperative goal. A BSCVA of 20/40 or better was observed in 93.9% of eyes and remained stable throughout the follow-up. Of the eyes with extremely high myopia (>-15.0 D), 63.3% gained 2 or more lines of BSCVA; of those with moderate myopia (-5.0 to -10.0 D), 23.5% gained 2 or more lines. The mean endothelial cell density change was 4.8% at 6 months, 2.4% at 1 year, 1.7% at 2 years, and 0.7% at 3 years. The incidence of persistent adverse events at 3 years was relatively low. Secondary surgical interventions included repositioning of the lens because of poor initial placement and lens exchange because of preoperative power calculation errors. Glare and halo effects during night driving were noted and were related to large pupils in young patients. CONCLUSION The Artisan lens is a safe, stable, efficacious, and predictable method to correct -5.0 to -20.0 D of myopia. This study suggests that the corneal endothelial cell loss is stabilized to the physiologically normal level after 3 years.

Retinal detachment following laser in situ keratomileusis

OBJECTIVE To report the clinical characteristics, surgical management and outcome of retinal detachment following laser in situ keratomileusis (LASIK) in myopic patients. PATIENTS AND METHODS Retrospective review of 10 eyes of 10 myopic patients with retinal detachment who had previously undergone LASIK surgery were analyzed. Included in the study were 7 males and 3 females, aged 22 to 68 years (35.2+/-2.8). RESULTS Mean spherical equivalent refraction was -10.51+/-3.90 D (ranging from -6.37 D to -17.00 D) before surgery. The time interval between the LASIK procedure and the development of retinal detachment varied from two months to nine months (5.2 +/- 2.78 months). The number of retinal breaks was one in 7 patients, two in 2 patients and three in 1 patient. The type of retinal breaks included 7 patients with horse shoe tears, 1 patient with a retinal hole, 1 patient with a giant retinal tear, and 1 patient with retinal dialysis. Retinal breaks were located anterior to the equator in 9 patients and posterior to the equator in 1 patient. Retinal reattachment was achieved with one operation in 8 eyes (80%) and the remaining 2 eyes required a second surgery for the reattachment of the retina. CONCLUSION This study suggests the possible association between retinal detachment and LASIK procedure in patients with myopia. Clinicians should be aware of retinal pathology predisposing to retinal detachment in patients undergoing LASIK.

Decreased tear secretion after laser in situ keratomileusis for high myopia.

PURPOSE To investigate the changes in tear secretion and tear film stability after excimer laser in situ keratomileusis (LASIK) for high myopia. METHODS One eye of 28 patients underwent unilateral LASIK for the correction of myopia with spherical equivalent refractions ranging from -6.37 to -18.25 D (mean, -11.98 +/- 3.45 D). Schirmer tear test values without anesthesia at 5 minutes and tear break-up time values were measured 4 weeks after LASIK. Unoperated contralateral eyes were used as a control for each patient. The Schirmer tear test and tear break-up time values were analyzed statistically using the independent t-test. RESULTS The mean Schirmer tear test value was 16.17 +/- 2.50 mm in the operated eyes and 21.07 +/- 7.03 mm in the unoperated (control) eyes of the same patients (P = .001). The mean tear break-up time value was 21.0 +/- 3.55 seconds in the operated eyes and 21.27 +/- 6.79 seconds in the control eyes (P = .85). CONCLUSION Tear secretion decreased following LASIK probably due to decrease in corneal sensitivity, but tear film stability appeared unaltered.

CHANGES IN TEAR FLOW AND TEAR FILM STABILITY AFTER PHOTOREFRACTIVE KERATECTOMY

PURPOSE To investigate the changes in tear flow and tear film stability after photorefractive keratectomy (PRK) for myopia. MATERIAL AND METHOD One eye of 32 patients underwent unilateral PRK procedure for the correction of myopia ranging from -1.50 to -6.00 diopters (D) (mean -3.65 +/- 1.55 D). Schirmer test values and break-up time (BUT) scores were measured 6 weeks after the PRK procedure. Unoperated, contralateral eyes were used as control eyes for each patient. The Schirmer test scores and BUT values were statistically analyzed using independent t test. RESULTS The mean Schirmer test value was 14.45 +/- 7.79 mm in the operated eyes. It was 28.83 +/- 5.89 in the control eyes. The decrease in Schirmer test value was statistically significant (t = 8.28, p = 0.0001). The mean BUT scores were 13.19 +/- 5.09 s in the operated eyes and 27.83 +/- 9.31 s in the control eyes. The decrease was statistically significant (t = 7.86, p = 0.0001). CONCLUSION PRK causes a decrease in tear flow and tear film stability that is probably caused by decreased corneal sensation after PRK.

Corneal interface abscess after excimer laser in situ keratomileusis

Laser in situ keratomileusis (LASIK) carries the risk of infection. We report a case culture-negative interface abscess following LASIK that was successfully treated with antibiotics and povidone iodine.

Photorefractive Keratectomy For Hyperopia and Aphakia with a Scanning Spot Excimer Laser

OBJECTIVE To study the safety, efficacy, predictability, and stability of photorefractive keratectomy (PRK) for hyperopia and aphakia. METHODS Fifteen eyes of 15 patients (mean age, 33 +/- 5.95 yrs) were enrolled in the study and divided into three groups. The first group was comprised of six eyes that had hyperopia ranging from +1.75 to +4.75 D; the second group had seven hyperopic eyes ranging from +5.00 to +9.75 D; the third group included two eyes of two aphakic patients. All eyes had PRK with a 193 nm argon fluoride excimer laser (Chiron-Technolas, Keracor 116) with a 10 Hz repetition rate and a fluence of 120 mJ/cm2. The total follow-up time in all eyes was 12 months. RESULTS In the lower hyperopia group, 0% eyes were within +/- 0.50 D and 66% (N = 4) of eyes were within +/- 1.00 D of emmetropia with the other two eyes between +1.00 and +2.00 D at 1 year after PRK. In the higher hyperopia group, all eyes had at least +3.00 D of hyperopia at 1 year. In the aphakic group, both eyes achieved less than 50% of the target correction of +10.00 D at 1 year. Final uncorrected visual acuity ranged from 20/20 to 20/30 in the lower hyperopia group, 20/30 to 20/50 in the higher hyperopia group, and count fingers in the aphakic group. CONCLUSIONS PRK is a relatively safe, stable, and effective procedure with reasonably good predictability for eyes with less than +5.00 D of baseline hyperopia, and poor predictability for eyes with more than +5.00 D of baseline hyperopia. PRK is ineffective in the correction of aphakia.

Corneal iron ring after hyperopic laser-assisted in situ keratomileusis.

PURPOSE To report a new corneal iron ring after hyperopic laser-assisted in situ keratomileusis (LASIK). METHODS Three patients underwent hyperopic LASIK for the correction of hyperopia in both eyes. Spherical equivalent refraction of the patients ranged from +3.37 to +6.50 diopters. LASIK procedure was performed using automated corneal shaper and 193-nm argon fluoride excimer laser. RESULTS Both eyes of the patients were noted to have a corneal iron ring located at the paracentral area at 6-7 months after surgery. The localization of iron ring corresponded with outside border of central steep zone. Twelve-month examination showed there was no change in color, shape, and density of corneal iron ring. CONCLUSIONS Corneal topographic changes induced by hyperopic LASIK may cause corneal iron ring to develop.

Comparison of Keratometric Data Obtained by Automated Keratometer, Dicon CT 200, Allegro Topolyzer, and Pentacam

PURPOSE To compare the keratometric values measured by the automated keratometer, two Placido-based computerized topography systems (Dicon CT 200 [Vismed Inc] and Allegro Topolyzer [WaveLight Inc]), and Scheimpflug analysis (Pentacam [Oculus Optikgeräte GmbH]). METHODS The keratometric data of 200 eyes from 200 patients evaluated for refractive surgery were reviewed retrospectively. Mean simulated keratometry (Sim K) and mean corneal astigmatism measured by the four devices were compared using repeated measures analysis of variance with Bonferroni correction. The analysis of agreement between two measurements was assessed using the method of Bland and Altman. RESULTS Mean Sim K as measured by the automated keratometer, Dicon CT 200, Allegro Topolyzer, and Pentacam was 43.39±1.50 diopters (D), 43.55±1.50 D, 43.45±1.50 D, and 43.43±1.45 D, respectively. The Dicon CT 200 measured the mean Sim K to be steeper and the automated keratometer measured the mean Sim K to be flatter than the other devices. Significant differences in corneal astigmatism were noted among the four devices except Dicon CT 200 versus Allegro Topolyzer and Allegro Topolyzer versus Pentacam comparisons (P<.013). For mean Sim K, the 95% limits of agreement between the Pentacam and other three devices were significantly wider than the other comparisons. In Bland-Altman plots comparing the Pentacam to the other devices, extreme outliers were present in 11 (5.5%) eyes. CONCLUSIONS Because of the wide distribution range and presence of extreme outliers, Pentacam data should be used cautiously in IOL power calculation and astigmatic keratotomy procedures.

Apical nodular subepithelial corneal scar after retreatment in hyperopic photorefractive keratectomy.

PURPOSE To report a complication, apical nodular subepithelial corneal scar, that can occur after hyperopic photorefractive keratectomy (PRK) retreatment. SETTING Istanbul University Eye Research Center, Istanbul, Turkey. METHODS Twelve eyes of 6 patients with apical nodular subepithelial corneal scar were retrospectively studied. Mean age of the 5 men and 1 woman was 30.2 years +/- 5.4 (SD). All eyes had hyperopic PRK retreatment for regression 9.5 +/- 1.44 months after primary hyperopic PRK. Mean spherical equivalent refraction of the residual hyperopia before retreatment was +4.67 +/- 0.81 diopters (D). All patients had a corneal haze grade of less than 1+. Hyperopic PRK retreatment was performed with a 193 nm excimer laser (Chiron Technolas Keracor 116). RESULTS Apical nodular subepithelial corneal scars developed within the first month of hyperopic PRK retreatment and progressed until the third month in 12 eyes of 6 patients. The lesion was round and symmetrical in both eyes, smaller than 2.0 mm, and centrally located. During the mean 40.66 +/- 2.46 month follow-up, the lesion did not change in size or density. Mean spherical equivalent refraction after retreatment was 2.88 +/- 0.88 D (range +1.50 to +4.00 D) at 1 month and +4.36 +/- 1.83 D at last follow-up. Refraction was unmeasurable in 3 eyes. Five eyes lost 1 line of best spectacle-corrected visual acuity and 7 eyes, 2 or more lines. The surface regularity indexes were higher than 2.00 in all the eyes. CONCLUSION Hyperopic PRK retreatment may cause the sight-threatening complication of apical nodular subepithelial corneal scar. This complication behaves unlike corneal haze and does not resolve spontaneously over time.

Two-year results of photorefractive keratectomy with scanning spot ablation for myopia of less than -6.0 diopters

BACKGROUND AND OBJECTIVE To investigate the efficacy, predictability, stability, and safety of photorefractive keratectomy (PRK) with scanning spot ablation for the treatment of myopia of less than -6.0 D. PATIENTS AND METHODS Twenty eyes of 20 patients (11 men, 9 women) were enrolled into the study. The mean age was 26.2 +/- 5.4 years. Mean spherical equivalent myopia was -3.53 +/- 1.13 D, ranging from -2.25 to -6.00 D. Patients underwent excimer laser PRK for the treatment of myopia. Follow-up time was at least 24 months in all patients. RESULTS Mean spherical equivalent refraction was +0.84 +/- 0.99 D at 1 month, +0.19 +/- 0.54 at 3 months, -0.01 +/- 0.53 at 12 months, and -0.13 +/- 0.50 at 24 months. There was a mean regression of 0.65 D between 1 and 3 months. At 24 months, 16 (80%) of the eyes remained within +0.50 D of emmetropia and 18 (90%) of the eyes remained within +/- 1.0 D of emmetropia. Nineteen (95%) of the eyes had uncorrected visual acuity of 20/40 or better. The mean corneal haze score was maximum at 3 months (0.88 +/- 0.22). There was no clinically significant corneal haze (greater than 2+). One eye (5%) lost 2 or more lines of best-corrected visual acuity. CONCLUSION Excimer laser PRK with the scanning spot ablation technique is effective, predictable, stable, and safe for the treatment of myopia of less than -6.0 D.