Yusuf Özertürk

Long-Term Results of Deep Anterior Lamellar Keratoplasty for the Treatment of Keratoconus

PURPOSE To evaluate the long-term endothelial cell density (ECD) changes and visual and refractive outcomes after deep anterior lamellar keratoplasty (DALK) using the big-bubble technique in eyes with keratoconus. DESIGN Retrospective interventional case series study. METHODS setting: Single hospital. patients: Two hundred forty-one eyes of 214 patients who underwent DALK for moderate to advanced keratoconus. main outcome measures: Intraoperative and postoperative complications, postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction, topographic astigmatism, and ECD. RESULTS Two hundred thirty-four procedures (97%) were completed as DALK. Big bubble was successfully achieved in 193 eyes (82.4%). In 7 eyes (3%), the procedure was converted to penetrating keratoplasty because of Descemet membrane macroperforations. Microperforations occurred in 18 eyes (7.5%). The mean follow-up time was 50.5 ± 22.2 months (range 24 to 96 months). UCVA was lower than 20/100 in all eyes preoperatively and better than 20/100 in 191 eyes (81.6%) postoperatively. BSCVA was 20/40 or better in 187 eyes (79.9%) and 20/20 or better in 38 eyes (16.2%). The mean (± SD) preoperative ECD that was possible in 166 eyes was 2797 ± 561 cells/mm(2). Mean (± SD) endothelial cell loss was 8.1% ± 4.6% at 1 year, 10.5% ± 5.7% at 2 years, 15.1% ± 14.8% at 6 years, and 22.5% ± 15.9% at 8 years. Stromal graft rejection episodes occurred in 4 eyes, which resolved with appropriate therapy. CONCLUSIONS Deep anterior lamellar keratoplasty that uses the big-bubble technique is effective in patients with keratoconus. Long-term endothelial cell loss was moderate and lower than penetrating keratoplasty grafts.

Effect of melatonin against oxidative stress in ultraviolet-B exposed rat lens.

PURPOSE To investigate the defensive effect of melatonin against oxidative stresses in ultraviolet-B (UVB) radiation induced cataract development. METHODS Young rats received 8 kJ/m(2) UVB for 15 min. For the intervention of cataract development intraperitoneal injection of melatonin (4 mg/kg daily for 1 week) following UVB exposure was performed. Lenticular glutathione peroxidase (GSHPx), catalase (CAT), superoxide dismutase (SOD) activities and glutathione (GSH), malondialdehyde (MDA) levels were determined in UVB-melatonin, UVB, and control groups. RESULTS One week after exposure in the UVB group, lens opacities were observed and CAT, SOD, and GSHPx activities, and GSH level were lower than control and MDA level was higher than control (p < 0.05). In the UVB-melatonin group CAT and SOD activities were lower than control (p < 0.05), and the MDA level was lower than the UVB group (p < 0.05). CONCLUSIONS These results suggest that melatonin may protect against the UVB-induced cataract development by directly quenching lipid peroxides and indirectly by enhancing the production of the endogenous antioxidant GSH.

Comparison of 2 intrastromal corneal ring segment models in the management of keratoconus

PURPOSE: To compare the outcomes of implantation of 2 models of intrastromal corneal ring segments (ICRS) to manage keratoconus. SETTING: Kartal Training and Research Hospital, Istanbul, Turkey. METHODS: This study evaluated eyes with keratoconus that had implantation of Keraring ICRS (Group A) or Intacs ICRS (Group B). The corneal tunnels were created mechanically or with a femtosecond laser. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, keratometry (K) readings (Orbscan II), and complications in the 2 groups were compared. RESULTS: Group A comprised 100 eyes and Group B, 68 eyes. The postoperative increase in UDVA and CDVA was statistically significant in both groups (P<.05). Group A had greater improvement in CDVA than Group B at 6 months and 1 year (both P<.001). At 1 year, the decrease in the mean maximum K power was statistically significant in Group A (51.27 diopters [D] ± 4.46 [SD] to 47.87 ± 3.39 D) and in Group B (51.12 ± 4.54 D to 47.58 ± 3.66 D) (P<.05). The mean reduction in maximum K was statistically significantly greater in Group A at 6 months and 1 year (P = .018 and P = .024, respectively). There were no statistically significant differences in visual or refractive results between femtosecond laser and mechanical tunnel creation. CONCLUSION: Although both ICRS models were effective and safe in managing keratoconus, the Keraring ICRS led to more improvement in CDVA and UDVA and a greater reduction in the maximum K value. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Penetrating keratoplasty versus deep anterior lamellar keratoplasty: comparison of optical and visual quality outcomes.

Purpose To evaluate and compare visual and optical performance outcomes by means of analysis of the contrast sensitivity function (CSF) and ocular higher order aberrations (HOA) in patients with keratoconus who had deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PK). Methods In this prospective, randomised case series, 174 eyes of 140 consecutive patients with moderate to advanced keratoconus were included. The big-bubble technique was attempted to perform DALK. Intraoperative and postoperative complications, uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), refraction, topographic astigmatism, CSF and ocular HOA were evaluated. Results The DALK and PK groups consisted of 99 and 75 eyes, respectively. Postoperative BSCVA was 20/40 or better in 64 eyes (85%) in the PK group and and 82 eyes (83%) in the DALK group (p>0.05). The mean spherical equivalent and maximum keratometry were −1.50 (−6.25 to +4.75) and 46.85 (40.60 to 56.00) in the PK group and −2.25 (−8.75 to +4.00) and 46.90 (40.60 to 53.60) in the DALK group, respectively. The differences were not statistically significant (p=0.08 and p=0.66, respectively). No significant differences in photopic contrast sensitivity were found for each of the spatial frequencies (p>0.05 for all). However, mesopic contrast sensitivity for three cycles/degree was significantly higher in the DALK group (p=0.01). No significant differences between groups were detected for any of the aberrometric parameters (p>0.05). Conclusions DALK is an alternative treatment option in eyes with moderate to advanced keratoconus, providing comparable results to PK in terms of visual acuity, refraction, CSF and HOA.

Comparison of mechanical and femtosecond laser tunnel creation for intrastromal corneal ring segment implantation in keratoconus: Prospective randomized clinical trial

PURPOSE: To compare the outcomes of mechanical and femtosecond laser–assisted tunnel creation for intrastromal corneal ring segment (ICRS) implantation in eyes with keratoconus. SETTING: Kartal Training and Research Hospital, Istanbul, Turkey. METHODS: In this prospective study, consecutive eyes with keratoconus were randomly assigned to have ICRS tunnel creation with a mechanical device or a femtosecond laser. Keraring ICRS with a 5.0 mm diameter and 160‐degree arc length were implanted in all cases. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction, and keratometry (K) readings were measured preoperatively and 1 year postoperatively, and the data in the mechanical group and the femtosecond group were compared statistically. RESULTS: One year postoperatively, there was significant improvement in UDVA, CDVA, K readings, spherical equivalent (SE), and manifest sphere and cylinder in both groups (P<.05). The UDVA improved by 2.4 lines in the mechanical group and 2.0 lines in the femtosecond group and the CDVA by 3.3 lines and 2.7 lines, respectively; the mean reduction in maximum keratometry was 4.50 diopters (D) and 4.70 D, respectively, and the mean reduction in SE, 3.18 D and 3.09 D, respectively. There were no statistically significant differences between the 2 groups in visual or refractive results (P>.05). Anterior corneal perforation, superficial segment placement, and segment extrusion occurred in 1 eye each in the mechanical group. Segment migration occurred in 1 eye in the femtosecond group. CONCLUSION: Despite intraoperative complications in the mechanical group, the visual and refractive outcomes were similar to those in the femtosecond group. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Adult strabismus and social phobia: a case-controlled study.

PURPOSE To determine the social phobia rate, social anxiety level, severity of depressive symptoms, and disease-related disability in adult strabismus patients. METHODS Forty-nine strabismus patients and 46 control subjects from 15 to 65 years of age were evaluated. A psychiatric interview focusing on social phobia and the Liebowitz Social Anxiety Scale (LSAS) were administered to each participant. All participants completed the Hospital Anxiety and Depression Scale (HADS), a psychiatric symptom checklist (Symptom Checklist 90-Revised; SCL-90R), and the Sheehan Disability Scale. RESULTS Social phobia was diagnosed in 26 of the 49 strabismus patients and in 8 of the 46 control subjects (p < 0.001). Strabismus patients demonstrated significantly greater scores in all of the subscores and the total scores of LSAS. They were more disabled in social life, family life, and at work. They also showed greater interpersonal sensitivity scores compared with the control group. Compared with strabismus patients without social phobia, the strabismus patients with social phobia demonstrated significantly greater depression scores in HADS and also scored in all dimensions of LSAS. Their social life and family life scores in disability scale and all scores in SCL-90-R except somatization were better than strabismus patients without social phobia. CONCLUSIONS In adult strabismus patients, social phobia is a frequent psychiatric comorbidity. Adult patients with strabismus need to be carefully evaluated for social phobia for an appropriate referral and treatment.

Intrastromal Corneal Ring Segment Implantation for the Treatment of Keratoconus

Purpose: To evaluate the safety and efficacy of intrastromal corneal ring segment implantation using both mechanical and femtosecond-assisted tunnel creation for the treatment of patients with keratoconus. Methods: A retrospective noncomparative interventional study including 96 eyes of 75 patients with keratoconus. All patients had contact lens intolerance and clear central corneas. Corneal tunnels were made using a femtosecond laser in 26 eyes (femtosecond group) and mechanically in 70 eyes (mechanical group). The Keraring (Mediphacos, Belo Horizonte, Brazil) was implanted in each eye, and a complete ophthalmic examination was performed, including visual acuity, refraction, and keratometric readings. Results: The mean preoperative uncorrected visual acuity for all eyes was 1.40 ± 0.39 logarithm of the minimal angle of resolution (logMAR) (mean ± SD) and improved to 0.60 ± 0.34 logMAR at the sixth month (n = 96, P < 0.001) and 0.50 ± 0.32 (n = 54, P < 0.001) at the 18th month. The mean preoperative best spectacle-corrected visual acuity (BSCVA) for all eyes (n = 96) was 0.68 ± 0.36 logMAR. The mean BSCVA was 0.29 ± 0.21 (n = 96, P < 0.001) at the sixth month and improved to 0.26 ± 0.20 (n = 54, P < 0.001) at the 18th month. There was a significant reduction in spherical equivalent refractive error from −5.88 ± 3.65 diopters (D) (n = 96) to −2.26 ± 1.98 D (n = 54, P < 0.001) at the 18th month. The mean preoperative maximum keratometry (Kmax) was 53.58 ± 5.90 D and decreased to 49.02 ± 4.70 (n = 96, P < 0.001) at 6 months and 48.57 ± 4.36 D (n = 54, P < 0.001) at the 18th month. Sixth month results of the mechanical versus femtosecond groups were as follows: improvement in uncorrected visual acuity (2.08 vs. 1.50 lines), improvement in BSCVA (2.93 vs. 2.19), reduction in spherical equivalent (3.78 vs. 3.75 D), and reduction in maximum keratometry (4.66 vs. 4.62 D). There was no statistically significant difference between both groups for any parameter. Conclusions: Keraring implantation is effective for the treatment of keratoconus, providing safety and good visual outcomes after both mechanical and femtosecond-assisted tunnel creation.

Fluorescein angiography-guided photodynamic therapy with half-dose verteporfin for chronic central serous chorioretinopathy.

Purpose: The purpose of this study was to evaluate the results of fluorescein angiog-raphy-guided photodynamic therapy with half-dose verteporfin in the treatment of chronic central serous chorioretinopathy with focal leakage areas. Methods: Eight cases with a history of central serous chorioretinopathy of ≥6 months were included. All eyes had one or more focal areas of active retinal pigment epithelial leak. Photodynamic therapy was applied with half-dose verteporfin (3 mg/m2), and the spot size was set limited to the area of active leakage shown on fluorescein angiography. Results: The mean duration of the last central serous chorioretinopathy episode was 12.50 months. The mean best-corrected visual acuity improved from 20/122 to 20/60 the first month (P = 0.017) and to 20/55 the first year after treatment (P = 0.018). Seven eyes (87.5%) had improved vision 1 year after treatment, and 1 eye (12.5%) had stable vision with a mean number of 3.61 gained lines. The mean central macular thickness was reduced from 366 ± 95 μm to 217 ± 32 μm the first month (P = 0.006). Conclusion: Fluorescein angiography-guided photodynamic therapy with half-dose verteporfin seems to be a rational and effective alternative to other methods in the treatment of chronic central serous chorioretinopathy with focal leakage on fluorescein angiography.

The effect of adjunctive Mitomycin C in Ahmed glaucoma valve implantation.

Purpose To evaluate the effectiveness and safety of adjunctive mitomycin C (MMC) in Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. Methods Twenty-two eyes of 22 patients who underwent AGV implantation with adjunctive MMC (0.5 mg/ml) for 3 minutes (Group A) were compared to a control group of 26 eyes of 26 patients (Group B) who received AGV implantation without MMC. Nine patients were female and 13 patients were male in Group A and 11 patients were female and 15 patients were male in Group B. The mean age was 56 years ranging from 13 to 77 in Group A and 58 ranging from 14 to 71 years in Group B. Success was defined as an intraocular pressure (IOP) between 4 and 21 mmHg with or without glaucoma medication and with no additional glaucoma surgery, phthisis, or loss of light perception. Results The probability of success at 1 year was 86.36% and 80.76% in Group A and Group B, respectively. The number of glaucoma medications decreased from 2.82 to 0.56 in Group A and from 2.65 to 0.73 in Group B. Postoperative hypotony as an early complication was higher in Group A (31.81% in Group A and 15.38% in Group B). As a late postoperative complication, tube exposure developed in 3 patients (13.63%) in Group A and no such complication was seen in Group B. There was no statistically significant difference in success and complication rates between the two groups (p>0.05). Conclusions Although adjunctive MMC in AGV implantation is safe and effective, it may not offer a better chance of surgical success compared with AGV implantation without MMC.

Corneal endothelium after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus: A four-year comparative study

Purpose: To compare the status of corneal endothelium and central corneal thickness within the first four postoperative years after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus. Materials and Methods: Thirty-nine eyes (Group A) which had PK and 44 eyes (Group B) which had DALK for the treatment of keratoconus were included in this retrospective study. The endothelial cell density (ECD), the mean endothelial cell area and the coefficient of variation of cell area were assessed with a non-contact specular microscope, and the central corneal thickness (CCT) was measured with an ultrasound pachymeter. Results: Mean ECD loss rate at two years was 36.24% in Group A and 18.12% in Group B (P<0.001). Mean ECD loss rate at four years was 47.82% in Group A and 21.62% in Group B (P<0.001). Mean annual ECD loss rate was calculated 14.12% per year in Group A and 5.78% per year in Group B. In the PK group, increase in mean CCT was 15.60% in two years and 15.03% in four years, while in the DALK group, mean CCT increased by 8.05% in two years and 9.31% in four years. Conclusions: As the majority of ectatic disorders such as keratoconus occur in young people, long-term endothelial cell survival following treatment with keratoplasty is essential for the long-term visual ability. Our finding that corneal endothelial cell loss in the DALK group occurs at a slower rate than in the PK group suggests DALK as a safer alternative to PK in these selected patients.