Halil Bahcecioglu

Reproducibility of corneal flap thickness in laser in situ keratomileusis using the Hansatome microkeratome

Purpose: To evaluate the reproducibility of flap thickness during laser in situ keratomileusis (LASIK) and to analyze the effect of preoperative central corneal thickness and corneal keratometric power on flap thickness. Setting: Department of Ophthalmology, Cerrahpasa Medical School, Istanbul, Turkey. Methods: One hundred forty eyes with a mean preoperative pachymetry of 554.4 &mgr;m ± 36.3 (SD) and a mean keratometry of 43.5 ± 1.9 diopters had LASIK using the Hansatome automated microkeratome (Bausch & Lomb Surgical) and a 193 nm argon–fluoride excimer laser (Summit SVS Apex Plus). The 180 &mgr;m microkeratome plate was used in all procedures. Corneal thickness was measured with an ultrasonic pachymeter (Advent, Mentor O&O Inc.) before and during the flap procedure, and the difference was taken as flap thickness. The data were analyzed using a 1‐tailed t test and Pearson correlation coefficient. Results: The mean flap thickness was 120.8 ± 26.3 &mgr;m. There was a low correlation between baseline central corneal thickness and corneal flap thickness (P = .6, r = 0.046). There was no correlation between preoperative keratometry and flap thickness (P = .01, r = 0.203). Conclusions: The Hansatome microkeratome does not always produce a corneal flap of the intended thickness. Factors other than keratometry and pachymetry must affect flap thickness.

Optical coherence tomography for evaluation of anatomical changes in the cornea after laser in situ keratomileusis

Purpose: To examine the use of optical coherence tomography (OCT) in evaluating anatomical changes after laser in situ keratomileusis (LASIK) and complications related to the interface and corneal flap. Setting: Istanbul University Eye Research Center and Department of Ophthalmology, Cerrahpasa Medical School, Istanbul, Turkey. Methods: Eleven eyes of 11 patients who had myopic LASIK were included in the study. Mean age of the 7 men and 4 women was 29.4 years ± 6.9 (SD). Cases analyzed included uneventful LASIK (4 eyes), epithelial ingrowth (5 eyes), and flap striae (2 eyes). Corneas were examined by OCT (Humphrey Systems). Results: Optical coherence tomography resolved corneal flap and residual stromal layers in all cases. The mean thickness of the corneal flap and residual stroma was 138.2 ± 16.5 &mgr;m and 321.7 ± 32.1 &mgr;m, respectively. Interface between the corneal flap and residual stroma was shown by OCT. Optical coherence tomography revealed that the eye with flap striae had flap displacement undetected by biomicroscopy. Epithelial ingrowth was shown as a highly reflective area. Conclusion: Optical coherence tomography appears to be a promising method for evaluating anatomical changes in the cornea after LASIK.

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.

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.

Intravitreal Bevacizumab (Avastin) Injection in Retinitis Pigmentosa

Purpose: To evaluate and report the effectiveness, visual, anatomical, and clinical outcome of intravitreal bevacizumab (Avastin) injection in patients with retinitis pigmentosa (RP). Methods: Our prospective study included 13 eyes of 7 patients (4 women and 3 men) in the age range of 25–69 years (mean 44.14 years) with cystoid macular edema (CME) secondary to RP. Intravitreal bevacizumab at a dose of 1.25 mg/0.05 ml was injected via a 28-gauge needle. The response rate to treatment was monitored functionally by visual acuity assessment and anatomically using the optical coherence tomography. Results: The baseline mean central macular thickness was 370.15 μ m (range 245–603 μ m. The central macular thickness decreased to 142.53 μ m (range 124–168 μ m) after bevacizumab injections. The pre- and post-treatment visual acuity ranges were 5/400–20/100 and 20/200–20/63, respectively. Conclusions: Our data reveal that intravitreal bevacizumab administration is effective for the treatment of CME in RP. Further studies with a larger population and longer follow-up period are warranted to assess the efficacy of the treatment.

Corneal iron ring associated with iatrogenic keratectasia after myopic laser in situ keratomileusis

A 23-year-old woman had bilateral myopic laser in situ keratomileusis (LASIK). Two months postoperatively, she reported decreased visual acuity. Biomicroscopic examination revealed a corneal epithelial iron ring around the central keratectasia on both corneas. The appearance of the ring pattern was similar to the iron deposits of the Fleischer ring of keratoconus.

Intravitreal Ranibizumab in the Treatment of Cystoid Macular Edema Associated With Retinitis Pigmentosa

PURPOSE To report and evaluate the anatomic, clinical, and visual acuity response after intravitreal ranibizumab (IVR) injection in patients with cystoid macular edema (CME) due to retinitis pigmentosa (RP). METHODS This study included 30 eyes of 30 patients with RP who had persistent CME at least 6 months despite medication with acetazolamide. Fifteen eyes of 15 eligible patients were treated with 0.5 mg IVR injection (treatment group). Fifteen eyes of 15 patients with the same characteristics who refused treatment were accepted as control group. The primary outcome of the study (morphologic restitution) was the complete or significant resolution of cystoid space on optic coherence tomography (OCT) without relapse or complication at 6 months. The serial changes in best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were measured. RESULTS Thirteen eyes (86.6%) in the treatment group had significant resolution of CME at 6 months after single IVR injection. The difference between the 2 groups in BCVA was not statistically significant (P > 0.05). The baseline mean +/- SD CFT for the treatment and control groups were 478 +/- 88 microm and 469 +/- 75 microm, respectively (P > 0.05). At 6 months after treatment, the mean +/- SD CFT of the treatment group improved to 272 +/- 65 microm whereas that in the control group was 480 +/- 92 microm (P < 0.001). CONCLUSIONS This investigation indicated that IVR may provide a new therapeutic approach for the treatment of CME secondary to RP. No adverse event was found to be associated with the treatment. Continued experience with IVR in this population will help establish its longer-term efficacy.

Silicone oil removal using a self-sealing corneal incision under topical anesthesia.

BACKGROUND AND OBJECTIVE To report the results of silicone oil removal from aphakic eyes using a self-sealing clear corneal incision under topical anesthesia. PATIENTS AND METHODS Twenty-two eyes of 22 patients who had pars plana vitrectomy combined with silicone oil injection underwent silicone oil removal under topical anesthesia using a self-sealing clear corneal incision. Mean time between silicone oil injection and removal was 3.1+/-1.42 months. Fourteen eyes were filled with 1300 cs of silicone oil and 8 eyes were filled with 5700 cs of silicone oil. The removal was performed with passive washout in the eyes filled with 1300 cs of silicone oil and with active aspiration in the eyes filled with 5700 cs of silicone oil. RESULTS All of the 22 silicone oil removal procedures performed under topical anesthesia had clear corneal incisions that did not require suturing at the end of surgery. Three cases that had 1300 cs of silicone oil required aspiration because of residual silicone oil bubbles. CONCLUSION Silicone oil can be removed from the aphakic eye using a self-sealing corneal tunnel incision under topical anesthesia.

Posterior Reversible Encephalopathy Syndrome After Intravitreal Bevacizumab Injection in Patient with Choroidal Neovascular Membrane Secondary to Age-Related Maculopathy

The posterior reversible encephalopathy syndrome (PRES), a complex of cerebral disorders including headache, seizures, visual disturbances, is associated with a variety of conditions in which blood pressure rises acutely. Arterial hypertension can occur in systemic administration of bevacizumab. A few cases of systemic injection of bevazicumab-induced PRES have been reported. In this article, we first report on a patient who developed PRES following intravitreal bevazicumab.