Ufuk Adigüzel

Serum oxidant/antioxidant balance in exfoliation syndrome

Background: To evaluate the relationship between the serum oxidant–antioxidant balance and the presence of exfoliation syndrome (XFS) in a prospective study.

Glutathione S-transferase M1, T1, and P1 gene polymorphism in exudative age-related macular degeneration: a preliminary report.

Purpose To elucidate whether the gene polymorphisms of glutathione S-transferase (GST) M1, T1, and PI are associated with the development of exudative age-related macular degeneration. Methods The authors genotyped 35 white patients with exudative age-related macular degeneration and 159 healthy controls. Genomic DNA from peripheral blood was examined using polymerase chain reaction and defined for the genetic polymorphisms of GST. Results No association was observed between GSTM1, GSTT1, and GSTP1 polymorphisms and age-related macular degeneration risk (p>0.05). The frequencies of the combination of the GSTM1 (null) and GSTP1 (mutant), GSTM1 (null), and GSTT1 (null) genotype polymorphisms in patients with exudative age-related macular degeneration differed greatly from those of the control group (p=0.001 OR [95% CI]: 7.70 [2.28–25.98] and p=0.007 OR [95% CI]: 3.88 [1.51–10.02], respectively). Conclusions The present study suggests that the GSTM1 (null) and GSTT1 (null), GSTM1 (null), and GSTP1 (mutant) combinations may be a genetic risk factor for the development of exudative age-related macular degeneration. However, the potential role of GST polymorphisms as a marker of susceptibility to age-related macular degeneration needs further studies in a larger number of patients.

Effects of topical vitamin E on keratocyte apoptosis after traditional photorefractive keratectomy.

Purpose: To evaluate the keratocyte apoptosis and effects of topical vitamin E on keratocyte apoptosis after photorefractive surgery. Methods: Rabbits were divided into 7 groups, and all groups were compared with controls after epithelial scraping, epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK), transepithelial PRK, production of a corneal flap with microkeratome and laser-assisted in situ keratomileusis (LASIK). The effects of topical Vitamin E treatment were investigated in the traditional PRK group. The terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy have been used to detect apoptosis in rabbit cornea. Results: Transepithelial PRK induced minimal keratocyte apoptosis, less than in all other refractive surgical procedures. The greatest amount of keratocyte apoptosis was observed after traditional PRK (p = 0.001), therefore we tested the effects of topical vitamin E in this group. The number of apoptotic keratocytes significantly reduced after vitamin E therapy (p < 0.005). Conclusion: Keratocytes undergo apoptosis after refractive surgery in response to mechanical epithelial removal, preparing of corneal flap and excimer laser stromal photoablation. The topical application of vitamin E immediately after surgery can prevent keratocyte apoptosis, and this result suggests that free radicals may be partly responsible for keratocyte apoptosis after excimer laser keratectomy.

Keratocyte apoptosis and corneal antioxidant enzyme activities after refractive corneal surgery.

Purpose Refractive corneal surgery induces keratocyte apoptosis and generates reactive oxygen radicals (ROS) in the cornea. The purpose of the present study is to evaluate the correlation between keratocyte apoptosis and corneal antioxidant enzyme activities after different refractive surgical procedures in rabbits.Methods Rabbits were divided into six groups. All groups were compared with the control group (Group 1), after epithelial scraping (Group 2), epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK: Group 3), transepithelial PRK (Group 4), creation of a corneal flap with microkeratome (Group 5) and laser-assisted in situ keratomileusis (LASIK, Group 6). Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy were used to detect apoptosis in rabbit eyes. Glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities of the corneal tissues were measured with spectrophotometric methods.Results Corneal Gpx and SOD activities decreased significantly in all groups when compared with the control group (P<0.05) and groups 2, 3 and 6 showed a significantly higher amount of keratocyte apoptosis (P<0.05). Not only a negative correlation was observed between corneal SOD activity and keratocyte apoptosis (cc: −0.3648) but Gpx activity also showed negative correlation with keratocyte apoptosis (cc: −0.3587).Conclusion The present study illustrates the negative correlation between keratocyte apoptosis and corneal antioxidant enzyme activities. This finding suggests that ROS may be partly responsible for keratocyte apoptosis after refractive surgery.

Cyclooxygenase-2 expression in primary and recurrent pterygium

Purpose Pterygium is a proliferative, inflammatory, and invasive ocular surface disease associated with excessive ultraviolet radiation exposure and has several tumor-like characteristics. Cyclooxygenase-2 (COX-2) is an inducible enzyme and recently increased expression of the enzyme was found in many cancers and premalign lesions. This study was conducted to identify the COX-2 expression in pterygium tissues. Methods Immunohistochemical staining using a primary antibody for COX-2 was performed on 30 specimens with primary pterygium (20 pterygium without recurrence and 10 pterygium which recurred during a 12-month follow-up), 11 specimens with recurrent pterygium, and 8 specimens of conjunctival tumor. As a control we used 10 specimens of normal conjunctiva. Extent and intensity of cytoplasmic and membranous staining in epithelial cells were evaluated. Results Higher expression of COX-2 was detected in conjunctival tumor (87.5%) specimens and recurrent pterygium specimens (72.7%) compared to the both normal conjunctiva (30%) and primary pterygium without recurrence (30%). COX-2 expression in primary pterygium tissues with recurrence (60%) was not different from primary pterygium without recurrence (p=0.114) and recurrent pterygium (p=0.537). However, recurrent pterygium tissues were found to express higher COX-2 than primary pterygium without recurrence (p=0.022). Conclusions COX-2 expression is increased in recurrent pterygium tissues and COX-2 expression may be a marker for the prediction of recurrence.

Persistent pupillary membranes in 3 siblings

We report 3 siblings from a nonconsanguineous white family with bilateral persistent pupillary membranes with dissimilar forms of severity. Two of the patients required no treatment; 1 was treated surgically for occlusion of the pupillary axis and moderate visual acuity decrease. Anterior segment examination was otherwise normal in the siblings. Although persistent pupillary membranes are usually sporadic, cases in which they are associated with other anterior chamber abnormalities might be inherited autosomal dominant. To our knowledge, this is the first report of a familial isolated persistent papillary membrane case with no other anterior chamber abnormality.

Intravitreal Triamcinolone Acetonide Treatment for Serpiginous Choroiditis

Purpose: To report the efficacy of intravitreal triamcinolone acetonide injection for acute treatment of a patient with serpiginous choroiditis. Methods: A 50-year-old male patient with serpiginous choroiditis presenting with the complaint of decreased visual acuity in his right eye for the last 10 days. The best corrected visual acuity (BCVA) of the patient was counting finger from 1 meter. Fundus examination and fundus fluorescein angiography of right eye revealed active macular choroiditis in right eye. Intravitreal triamcinolone acetonide (4 mg/0.1 ml) was injected into vitreous, and the patient was followed with visual acuity testing, intraocular pressure measurement, and fundus examination, including fundus fluorescein angiography. Results: Visual acuity of the patient improved to 20/100 after 2 weeks in spite of the triamcinolone crystals, and to 20/50 after 4 weeks with a single dose intravitreal triamcinolone acetonide injection. Complete resolution of the active lesion has been maintained during the 6 months of follow-up. Conclusions: Single dose intravitreal triamcinolone acetonide injection is sufficient for controlling the active lesions in serpiginous choroiditis. It needs further evaluation as an alternative treatment for achieving rapid and significant visual acuity recovery.

Corneal iron ring after hyperopic photorefractive keratectomy

PURPOSE To report the incidence and course of corneal iron deposition after hyperopic photorefractive keratectomy (PRK). SETTING Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. METHODS Between January 1995 and December 1997, 62 eyes had PRK to correct hyperopia. RESULTS Nine eyes developed corneal iron ring 5 to 8 months (mean 6.25 months +/- 1.3 [SD]) after PRK for hyperopia. The rings persisted during the mean follow-up of 19 +/- 11.09 months. CONCLUSION The ring-shaped iron deposition after PRK for hyperopia must be differentiated from the Fleischer ring. Our results suggest that the slitlamp findings of peripheral corneal iron deposition in hyperopic PRK patients correlate with achieved correction.

Effects of intravitreal bevacizumab in repeated doses: an experimental study.

Purpose: To evaluate the effects of repeated 1.25-mg intravitreal bevacizumab injections on cornea and uveoretinal tissues using histologic and biochemical analyses. Methods: Twenty-four New Zealand albino rabbits were used. Twelve rabbits received an injection of bevacizumab in their right eyes three times with an interval of 25 days (Group 1); their contralateral eyes served as controls (Group 2). Six rabbits had an injection of vehicle in both eyes (Group 3), with the same regimen as bevacizumab, and six rabbits’ eyes were used as a sham group (Group 4). Enucleated eyes were used for histologic and biochemical analyses, which included the activities of caspase 3 and 8 enzymes, glutathione content, catalase activity, and malondialdehyde content. Results: No inflammation in aqueous humor and no sign of corneal or uveoretinal toxicity was found in bevacizumab-injected eyes. The difference of activity of corneal caspase 8 enzyme between Groups 1 and 2 and between Groups 1 and 4 was statistically significant (P < 0.05). In the uveoretinal tissue, in Group 1, the activities of caspase 3 and 8 enzymes were the lowest, and uveoretinal malondialdehyde content was also significantly lower than Group 4. Conclusion: A repeated dose of intravitreal bevacizumab injection did not cause a toxic effect on cornea and uveoretinal tissue. Biochemically, it also did not cause any apoptosis, oxidative reaction, or lipid peroxidation. Instead, bevacizumab injection caused a considerable decrease in the apoptotic enzyme activities and lipid peroxidation in the uveoretinal tissue. Further studies are needed to be conducted for possible detrimental side effects and apoptotic and oxidative effects of repeated bevacizumab injections on both the injected and the contralateral eyes.

An Unexpected Outcome of Blunt Ocular Trauma: Rupture of Three Muscles

Introduction: Traumatic strabismus due to isolated extraocular muscle rupture is uncommon. Treatment usually depends on the severity of both the subjective and objective findings. Methods: We report a male patient with restricted abduction and supraduction in the right eye follow ing a blunt ocular trauma. The exploration revealed the rupture of superior rectus, superior oblique, and lateral rectus muscles. Only lateral rectus muscle could be sutured to the proximal segment. Superior rectus and superior oblique muscles were severed brutally, so that repairing was not possible. Results: On the day after exploration and primary suturation, there was 25 prism diopters (PD) hypotropia and 15 PD esotropia in his right eye with severe limited supraduction and abduction. His major complaint was a large vertical diplopia which resolved partially with the prismatic glasses prescribed. After 6 months follow-up, medial rectus and inferior rectus recession was performed in the right eye. The patient had a limited but improved abduction after the operation. He was orthotropic and had a single binocular vision in the primary position. Discussion: In suspected extraocular muscle ruptures, orbital imaging methods and surgical exploration should be considered promptly. MRI may be mandatory to demonstrate the severed muscles in cases with persistent diplopia and normal CT. Prognosis is usually better in patients having partial extraocular muscle damage and treatment options should be evaluated on patient basis.