Ahmet Hondur

Nonpenetrating glaucoma surgery: meta-analysis of recent results.

PurposeTo evaluate the efficacy of nonpenetrating glaucoma surgery for open angle glaucoma with respect to target intraocular pressure (IOP) and severity of glaucoma. Materials and MethodsA literature search with the terms “nonpenetrating glaucoma surgery, deep sclerectomy (DS), viscocanalostomy (VC), and open angle glaucoma” was carried out for the reports in the last 5 years. Studies encompassing only combined glaucoma and cataract surgery were excluded. Measurement of effectiveness was determined on the basis of achievement of target IOP. Data related to postoperative goniopuncture and needling with antimetabolite application were noted. ResultsThe percentage of cases achieving ≤21 mm Hg was 48.6% after primary DS, 68.7% after DS with implant, 67.1% after DS with antimetabolite, 51.1% after primary VC, and 36.8% after VC with antimetabolite or implant. Visual field parameters were almost exclusively not available; whereas cup/disk ratio and target IOP lower than 21 mm Hg were available in very few reports. With lower set IOP targets, the rates of success varied between 35% and 86% for DS, and between 10% and 67% for VC. The mean follow-up of the studies were mostly in the range of 3 years. ConclusionsNonpenetrating glaucoma surgery seems to provide IOP reduction into the high teens. Its potential to achieve lower target IOPs seems to be low. Longer-term studies, with data related to glaucoma severity and proper target IOPs are required.

Pregnancy-induced progression of keratoconus.

Purpose: To report eyes with keratoconus that progressed during pregnancy. Methods: Seven eyes of 4 patients with progression of keratoconus during pregnancy were included in this study. The mean age of patients and the mean follow-up duration were 29.3 years and 39 months, respectively. Progressive keratoconus was documented with changes in refraction, corneal topography, and rigid gas-permeable lens fitting pattern. Patients with accompanying systemic and ocular diseases associated with keratoconus, uncontrolled atopic disease, and eye rubbing were excluded. Results: Mean increase in spherical equivalent refraction and simulated keratometry values were 1.4 ± 1.1 and 1.1 ± 0.8 diopters, respectively. In eyes wearing rigid gas-permeable lenses, increase in corneal apical touch and decrease in the base curve radius of the best-fitting contact lens were observed. Conclusions: Hormonal changes during pregnancy may affect corneal biomechanics negatively, and pregnancy may be a previously unrecognized risk factor for progression of keratoconus. To our knowledge, this is the first study showing pregnancy-induced keratoconus progression in patients with no accompanying disease.

Microbiologic study of soft contact lenses after laser subepithelial keratectomy for myopia.

Purpose. To evaluate the extent and agents of bacterial contamination of bandage disposable soft contact lenses after laser subepithelial keratectomy (LASEK) and to correlate the findings with clinical data. Methods. Disposable soft contact lenses were collected from 52 eyes of 26 consecutive patients treated with LASEK for myopia. The patients were treated with a fixed combination of tobramycin and diclofenac until epithelial closure. The lenses were removed on the fourth or fifth postoperative day with sterile forceps and immediately placed in sterile tubes containing culture media brain–heart infusion broth. The lenses were evaluated for microbial colonization. Results. Of the 52 contact lenses analyzed, six (11.5%) had positive cultures. However, no clinical finding of infection was noted. Isolated microorganisms were coagulase-negative staphylococci (two lenses), Stenotrophomonas maltophilia (two lenses), Acinetobacter species (one lens), and Aeromonas hydrophila (one lens). Except for one case, the microorganisms were sensitive to the administered antibiotic. Conclusions. The risk of infectious keratitis after LASEK seems to be low. Except for staphylococci, the isolated microorganisms have not been previously reported to colonize the ocular surface or cause keratitis after refractive surgery. These findings may suggest a changing trend of potentially infectious agents after surface ablation.

Laser subepithelial keratomileusis for myopia of -6 to -10 diopters with astigmatism with the MEL60 Laser

PURPOSE To evaluate the efficacy, predictability, and safety of laser subepithelial keratomileusis (LASEK) for treatment of high myopia with astigmatism. METHODS LASEK was performed in 61 eyes of 36 consecutive patients with myopic spherical equivalent refraction of -6.00 to -10.00 D using the Aesculap-Meditec MEL60 excimer laser. Data were collected prospectively with a follow-up of 6 to 17 months. Main outcome measures recorded were UCVA, BSCVA, residual refractive error, corneal haze, and complications. RESULTS Ninety-six percent of eyes achieved 20/40 or better UCVA at 1 month. At 12 months, 64% of eyes achieved 20/20 and 92% achieved 20/40 or better UCVA. Two eyes lost 2 lines of BSCVA at 6 or 12 months. Accuracy of correction was +/- 0.50 D from emmetropia in 82% of eyes, and +/- 1.00 D in 90% at 12 months. No eye showed more than grade 1 haze. Grade 1 haze was observed in three eyes at 12 months. One patient had mild postoperative keratitis, which was successfully treated. CONCLUSIONS LASEK with the Aesculap-Meditec MEL60 excimer laser appeared to be safe, effective, and highly predictable in treating high myopia.

A Clinical and Confocal Microscopic Comparison of Transepithelial PRK and LASEK for Myopia

Purpose. To compare the clinical and confocal microscopic results of transepithelial PRK versus LASEK for correction of myopia. Materials and Methods. Twelve patients with myopia received transepithelial PRK in one eye and LASEK in the other. In transepithelial PRK-treated eyes, the corneal epithelium was removed with 40 microns of excimer laser ablation and in LASEK-treated eyes with 25-second application of 18% ethanol. Time to epithelial healing, ocular discomfort, uncorrected and best corrected visual acuities, manifest refraction, haze, greyscale value, and keratocyte apoptosis in confocal microscopy were recorded. Results. The mean time to epithelial healing was significantly longer after LASEK (4.00 ± 0.43 versus 3.17 ± 0.6 days). On day 1, ocular discomfort was significantly higher after transepithelial PRK. The grade of haze, keratocyte apoptosis, and greyscale value in confocal microscopy were significantly higher in transepithelial PRK-treated eyes at 1 month. All transepithelial PRK- and LASEK-treated eyes achieved 20/25 or better UCVA and were within ±1.00 D of emmetropia at final visits. Conclusions. Both transepithelial PRK and LASEK offer effective correction of myopia at 1 year. However, LASEK appeared to induce less discomfort and less intense wound healing in the early postoperative period.

Long term results of Epi-LASIK and LASEK for myopia

PURPOSE To evaluate the long term clinical and confocal results of mechanical (Epi-LASIK) versus alcohol-assisted laser epithelial keratomileusis (LASEK) for correction of myopia. SETTING Gazi University Medical School, Department of Ophthalmology, Ankara, Turkey. DESIGN Retrospective study. METHODS Twenty-two eyes treated with LASEK and twenty eyes treated with Epi-LASIK were evaluated with a mean follow-up duration of 45 months. Mechanical separation of the epithelium was performed with Lasitome epithelial separator, and alcohol-assisted separation with 25s application of 18% alcohol. Laser ablation was performed with the ESIRIS laser. All patients were examined daily until epithelial closure; at 1, 3, 6, and 12 months; and every year subsequently. Main outcome measures were uncorrected visual acuity (UCVA), manifest refraction, haze, and gray scale value in confocal microscopy, efficacy and safety indexes. RESULTS Preoperative myopic spherical equivalent refraction was -4.65 ± 1.74 D in the LASEK and -3.87 ± 1.30 D in the Epi-LASIK-treated eyes (p=0.36). Of both LASEK and Epi-LASIK-treated eyes, 95% achieved 20/25 or better final UCVA. The grade of haze and mean gray scale value in confocal microscopy were similar in LASEK and Epi-LASIK-treated eyes at all postoperative periods. The efficacy index was 0.94 in LASEK group and 0.96 in Epi-LASIK group (p=0.44). The safety index was 1.01 in LASEK group and 1.02 in Epi-LASIK group (p=0.42). CONCLUSIONS Both LASEK and Epi-LASIK offer safe and effective correction of myopia in the long term.

Apoptosis in Orbital Fibroadipose Tissue and its Association with Clinical Features in Graves' Ophthalmopathy

Purpose: To evaluate the rate of apoptosis in orbital fibroadipose tissue in Graves’ ophthalmopathy (GO) patients and investigate its associations with disease characteristics. Methods: Orbital tissue samples were obtained during decompression surgery from 25 GO patients. Disease activity was evaluated using the Clinical Activity Score, while the clinical features of GO were evaluated using the Total Eye Score (TES). Tissue samples of 12 patients without any thyroid or autoimmune disease were studied as controls. The rate of apoptosis was evaluated with a terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) assay, and ultrastructural features of apoptosis were evaluated with electron microscopy. Results: The rate of apoptosis in orbital fibroadipose tissue was significantly higher in GO cases than in the control group (p < 0.001) and significantly correlated with TES (r: 0.545; p = 0.005). The rate of apoptosis was 7.9% ± 6.5%, and 22.0% ± 7.8% in type 1 and type 2 cases, respectively (p = 0.001). The rate of apoptosis was 21.6% ± 7.5% in eyes showing dysthyroid optic neuropathy (DON) and 6.7% ± 5.4% in eyes without DON (p = 0.005). Conclusions: The rate of apoptosis was high in the orbital fibroadipose tissue of GO cases and was related to the clinical features of the disease.

A short duration transient ischemia induces apoptosis in retinal layers: An experimental study in rabbits

Purpose To investigate retinal cell apoptosis in an experimental transient, short duration ocular ischemia model. Methods An experimental ischemia model, which simulates creating temporary high intraocular pressure to control intraocular bleeding during pars plana vitrectomy, was set up. Rabbits were randomly divided into three groups. Group 1 was the control group. In Group 2, intraocular pressure was increased to 97 mmHg for 5 minutes. In Group 3, intraocular pressure was increased to 97 mmHg for 10 minutes. After 24 hours, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling assay was used to detect retinal apoptosis in rabbit eyes. Only nuclear staining in retinal cells was counted. Results Groups with 5 minutes and 10 minutes of ischemia showed significantly higher amount of ganglion cell layer apoptosis when compared with the control group (p<0.05). Light microscopy and standard hematoxylin-eosin did not show any significant damage in the retina cells. Conclusions Apoptotic cell death in the retinal cell layers occurs in temporary ischemia-reperfusion as early as 5 and 10 minutes duration.

Measurement and clinical implications of choroidal thickness in patients with inflammatory bowel disease

PURPOSE Ocular inflammation is a frequent extraintestinal manifestation of inflammatory bowel disease (IBD) and may parallel disease activity. In this study, we evaluated the utility of a choroidal thickness measurement in assessing IBD activity. METHODS A total of 62 eyes of 31 patients with IBD [Crohns disease (CD), n=10 and ulcerative colitis (UC), n=21] and 104 eyes of 52 healthy blood donors were included in this study. Choroidal thickness was measured using enhanced depth imaging optical coherence tomography. The Crohns disease activity index (CDAI) and the modified Truelove Witts score were used to assess disease activity in CD and UC, respectively. RESULTS No significant differences in mean subfoveal, nasal 3000 μm, or temporal 3000 μm choroidal thickness measurements (P>0.05 for all) were observed between IBD patients and healthy controls. Age, smoking, CD site of involvement (ileal and ileocolonic involvement), CDAI, CD activity, and UC endoscopic activity index were all found to be significantly correlated with choroidal thickness by univariate analysis (P<0.05). Smoking (P<0.05) and the CD site of involvement (P<0.01) were the only independent parameters associated with increased choroidal thickness at all measurement locations. CONCLUSIONS Choroidal thickness is not a useful marker of disease activity in patients with IBD but may be an indicator of ileal involvement in patients with CD.

A histological study of rabbit corneas after transepithelial corneal crosslinking using partial epithelial photoablation or ethanol treatment

AIM To evaluate the histological changes after transepithelial corneal crosslinking (CXL) using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study. METHODS Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement (group I). Four eyes received partial thickness epithelial ablation with excimer laser (group II). Twelve eyes were treated with different durations (30s and 60s) and concentrations (18% to 48%) of ethanol (group III). Riboflavin was applied for 30min intervals along with topical proparacaine drops with benzalkonium chloride, and 370 nm irradiation was performed for 30min, while riboflavin was instilled every 3min. Four eyes (group IV) received 48% ethanol for 30s without riboflavin and irradiation. Eyes were collected after 24h and examined histologically. RESULTS All eyes in group I showed keratocyte loss in the superficial 300 µ of corneal storma. In group II, 1-4 layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 µ to 300 µ of cornea. CONCLUSION Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24% concentration and up to 60s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thickness excimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.