İbrahim F. Hepşen

Effects of some probable antioxidants on selenite-induced cataract formation and oxidative stress-related parameters in rats

The effect of several natural and synthetic compounds on selenite-induced cataract was investigated in rat pups. Simultaneous determination of glutathione S-transferase (GST), selenium dependent glutathione peroxidase (Se-GPx), catalase (CAT), superoxide dismutase (SOD) activities and malondialdehyde (MDA) levels were carried out in the lens, erythrocyte and plasma. The results showed that propolis, diclofenac, vitamin C (Vit-C) and quercetin prevented cataract formation to the extent of 70, 60, 58.4, and 40%, respectively. Standardized extract of Ginkgo biloba (Egb 761) did not affect the cataract formation. Selenite treatment caused a significant decrease in the activity of erythrocyte SOD. This was accompanied by a simultaneous increase in the levels of MDA either in lens and in plasma. A significant increase was shown in erythrocyte GST (substrate ethacrynic acid; eaa), and GPx activities and lens GST (substrate chlorodinitro benzene; cdnb) activity. Antioxidant treatment caused significant changes in enzyme activities and MDA levels. There was no effect of selenite and antioxidants on total body weight increase during the course of the study. Blood parameters did not correlate to lens parameters following selenite treatment. Our results suggest that antioxidant supplementation following selenite exposure may prevent the cataract formation and may enhance antioxidant defence of blood and lens.

The effect of reading and near-work on the development of myopia in emmetropic boys: a prospective, controlled, three-year follow-up study.

This study aimed to investigate the effect of reading and near work on myopic development in emmetropic boys in school age. It involved totally 114 children in two groups. Right eyes of 67 randomly selected students (mean age=12.93) with mean 6 h of reading and near work (Group 1) were compared with the right eyes of 47 apprentices (mean age=12.96) working as skilled laborers (Group 2). Cycloplegic refraction, keratometric readings and biometric measurements including anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD) and axial length (AL) were performed for 3 years at 18 month intervals. Two analyses were conducted: (1) for subjects in both groups with baseline refractive error from +0.50 to -0.50 D; (2) for all subjects in both groups with baseline refractive error from +1.00 to -1.00 D. For subjects with baseline refractive error of +/-0.50 D, myopic shift was present in 20 of 41 (48.8%) in group 1 and in seven of 37 (18.9%) in group 2 at the end of the study. The magnitude of the myopic shift was 0.56 and 0.07 D in group 1 and 2, respectively. For subjects with a baseline refractive error of +/-1.00 D, myopic progression was present in 40 of 67 (59.7%) in group 1 and in 10 of 47 (21.3%) in group 2 at the last readings. In this larger refractive range, the magnitude of the myopic shift was 0.61 and 0.12 D in group 1 and 2, respectively. The mean ACD, VCD and AL were significantly higher in the last readings after 36 months than in the first readings (for each, P=0.0001) in group 1. There was no statistically significant difference between two measurements of these parameters in group 2. The final keratometric dioptric readings were lower than the first values (for each, P=0.0001) in both groups at the end of the study. This prospective and controlled study suggested that reading and near work, important environmental factors, might cause refractive myopic shifts in emmetropic students. The myopic shift was primarily related to significant increases in ACD, VCD and AL in this young age group.

Topically Applied Water Extract of Propolis to Suppress Corneal Neovascularization in Rabbits

Purpose: Propolis, a natural honey bee hive product, has anti-inflammatory and antioxidative properties. We aimed to assess the possible contribution of topically applied propolis to the suppression of corneal neovascularization (CNV). Methods: The effect of a water extract of propolis (WEP) 1% drops (group 1) in comparison with dexamethasone 0.1% (group 2) and saline (group 3) on CNV was tested in rabbit corneas injured by silver nitrate cauterization. The extent of CNV was quantitated as the area of CNV and the percent area of CNV for each cornea of the three groups (12 right eyes per group) in the first week of the treatment. The mean percent CNV was used for statistical analysis. Results: The corneas treated with the topical WEP 1% had an almost equal percent CNV as compared with the corneas treated with topical dexamethasone 0.1% and had less percent CNV than the control eyes. The quantitative analysis in groups 1, 2 and 3 revealed that the mean percent CNV was 41.0 ± 14.1, 39.4 ± 11.0 and 56.9 ± 18.4, respectively. The differences between both groups 1 and 3 as well as groups 2 and 3 were statistically significant (p = 0.02 and p = 0.01, respectively), whereas the difference between groups 1 and 2 was not significant (p = 0.86). Conclusions: The topical application of a WEP 1% has an inhibitory effect on CNV in the rabbit’s cornea. The inhibitory effect of propolis was shown to be comparable to that of topical dexamethasone 0.1%, a potent inhibitor of angiogenesis. We suggest that the effect of propolis may partially be due to its inhibitory effect on the activity of both cyclo-oxygenase and lipo-oxygenase.

Weill-Marchesani syndrome in three generations

Background Weill-Marchesani syndrome is a rare systemic connective tissue disorder consisting of brachymorphy, brachydactyly, ectopia lentis, spherophakia and glaucoma.Methods We report 6 patients with Weill-Marchesani syndrome (with or without ocular involvement) in three generations, identified by screening 26 members of two families. This is the largest family in the literature showing an autosomal dominant pattern of inheritance.Results Presenile vitreous liquefaction was present in all the younger cases. Weill-Marchesani syndrome was full-blown in two cases in the third generation, in which asymmetrical axial length and glaucomatous damage were present. To our knowledge this is the first report regarding asymmetrical axial length and glaucomatous damage, and presenile vitreous liquefaction in Weill-Marchesani syndrome with or without ocular involvement.Conclusions The longer axial length might be the precursor of impending severe glaucomatous damage. Presenile vitreous liquefaction in subtle young cases should alert the physician to the diagnosis of Weill-Marchesani syndrome on screening of the family members.

Comparison of the results of primary and secondary implantation of flexible open-loop anterior chamber intraocular lens

Purpose To assess and compare the results of primary and secondary implantation of flexible open-loop anterior chamber intraocular lenses (AC-IOLs).Methods A series of 57 eyes of 56 patients with flexible AC-IOLs were reviewed in two groups. In group I (n = 35) an AC-IOL was implanted primarily, because of posterior capsule problems during extracapsular cataract extraction (ECCE), and in group II (n = 22) secondarily after intracapsular cataract extraction (ICCE). Follow-up was from 12 to 38 months.Results Mean post-operative best-corrected visual acuity in group I was significantly lower (20/37.38) than that of group II (20/29.20) (p = 0.044). Best corrected visual acuity of 20/40 or better was achieved in 19 of 29 eyes (65%) in group I, and in 16 of 21 eyes (76%) in group II. The difference was not statistically significant (p < 0.05). In group II18 eyes (86%) maintained or improved visual acuity. In group 1,17 eyes (49%) had a total of 22 complications, while 7 eyes (32%) had 9 complications in group II (p > 0.05).Conclusions Flexible open-loop AC-IOLs are suitable for both primary and secondary implantation to correct aphakia. Secondary implantation of flexible open-loop AC-IOLs after ICCE seems to have a more favourable visual outcome and a lower complication rate than primary implantation in complicated ECCE cases.

Myopic shift from the predicted refraction after sulcus fixation of PMMA posterior chamber intraocular lenses

BACKGROUND To evaluate the refractive results of sulcus-fixated polymethylmethacrylate (PMMA) posterior chamber intraocular lenses (PC IOLs) after cataract surgery with and without posterior capsule complications. METHODS The charts of patients who had undergone cataract surgery were reviewed, and eyes that had received sulcus-fixated PMMA PC IOLs were included in the study. Postoperative refraction, predicted postoperative refraction for in-the-bag IOL with the same diopter, intraoperative posterior capsular complications and vitrectomy, axial eye length, incision type (corneal or scleral), and surgery type were recorded and analyzed. The difference between actual postoperative refraction and predicted refraction for the in-the-bag lens was calculated for each patient. RESULTS Of 143 patients (84 men and 59 women), 162 eyes with a sulcus-fixated posterior chamber intraocular lens were investigated. Mean age was 63.7 +/- 12.1 years. A mean myopic shift of -1.02 +/- 0.96 D from the predicted in-the-bag refraction was found. There were no significant differences between eyes with or without vitreous loss-vitrectomy (p = 0.8), eyes with scleral or corneal incisions (p = 0.11), and eyes having phacoemulsification or extracapsular cataract extraction (p = 0.93). In terms of axial length, there were no significant differences between long, normal, or short eyes (p = 0.85). INTERPRETATION Sulcus fixation of a PMMA IOL originally planned for in-the-bag fixation caused approximately -1.00 D myopic shift in this study. We recommend that when sulcus fixation is necessary PMMA IOL power should be approximately 1.25 to 1.50 D less than the power for in-the-bag fixation. Axial length, incision type, vitreous loss and use of vitrectomy, and type of the surgery do not appear to alter the postoperative refraction significantly in eyes with sulcus fixation.

Lenticular astigmatism in tilted disc syndrome

Purpose: To evaluate whether an abnormal optic disc shape in patients with tilted disc syndrome (TDS) is associated with an abnormal configuration of the crystalline lens measured as lenticular astigmatism. Setting: Department of Ophthalmology, Inönü University Medical Faculty, Turgut Özal Medical Center, Malatya, Turkey. Methods: This cross‐sectional masked case‐control study comprised 32 eyes of 32 patients with established TDS (13 men, 19 women; mean age 21.31 years ± 7.05 [SD]) and 20 age‐ and sex‐matched healthy control subjects (8 men, 12 women; mean age 22.65 ± 7.11 years) with a comparable amount of myopic astigmatism (spherical equivalent) without TDS. The optic disc was morphometrically analyzed by planimetric evaluation of optic disc photographs. The total refractive and keratometric corneal astigmatism was obtained, and lenticular astigmatism was calculated by vector analysis. The Mann‐Whitney U test was used for statistical analysis; 1 eye of each patient was evaluated in both groups. A P value less than 0.05 was considered statistically significant. Results: The mean spherical equivalent refraction was comparable in TDS patients (−4.73 ± 1.12 diopters [D]) and controls (−4.28 ± 1.29 D) (P = .210). The mean total astigmatism was higher in TDS patients (−2.96 ± 1.04 D) than in the controls (−2.51 ± 1.09 D), but the difference was not significant (P = .151). The mean corneal astigmatism was comparable in TDS patients (−2.07 ± 0.83 D) and controls (−2.28 ± 0.87 D) (P = .454), but the calculated mean lenticular astigmatism was significantly higher in TDS patients (−1.31 ± 0.98 D and −0.20 ± 0.35 D, respectively) (P < .001). Twenty‐nine of 32 TDS patients (90.6%) had lenticular astigmatism; in 16 (50%), it was greater than −1.00 D. Lenticular astigmatism was present in 7 controls (35%); in 2 (10%), it was greater than −1.00 D. The mean keratometry was significantly higher in TDS patients (43.84 ± 1.06 D) than in the controls (42.75 ± 1.45 D) (P = .011). Conclusions: Clinically significant lenticular astigmatism was present in TDS patients. If an abnormal optic disc shape is found on ophthalmoscopy, lenticular astigmatism as well as corneal astigmatism should be carefully evaluated to prevent an unsatisfactory refractive outcome, especially in refractive surgery candidates.

Does convergence, not accommodation, cause axial-length elongation at near? A biometric study in teens.

To determine whether convergence rather than accommodation has a primary effect on the changes in axial length and other biometric components during near fixation, we measured the anterior chamber depth, lens thickness, vitreous length and axial length in the right eyes of 124 young male subjects while their left eyes focused at distance (6 m) and near (20 cm). The measurements were performed before and after cycloplegia in the right eye, so we aimed to study biometric components of the eye in the states of accommodation and nonaccommodation, but converging at near. While the left eye focused at near, the axial length increased significantly with and without cycloplegia (p < 0.0005 and p < 0.0005). The vitreous length was the main increasing ocular biometric component at near both with and without cycloplegia (p < 0.044 and p = 0.001, respectively). At near, there was no difference between two mean axial length and two vitreous length measurements both with and without cycloplegia (p = 0.672 and p = 0.595, respectively). Under cycloplegia, anterior chamber depth also increased significantly at near fixation (p = 0.012). Axial elongation at near fixation, mainly due to an increase in vitreous length, may result from the effect of accommodative convergence rather than accommodation itself. Much use of convergence, not accommodation, may be one of the contributing factors in adult onset and adult progression of myopia.

Comparison of dynamic contour tonometry and noncontact tonometry in ocular hypertension and glaucoma

PurposeTo assess the agreement in the measurement of intraocular pressure obtained by dynamic contour tonometer (DCT) and noncontact tonometer (NCT) in patients with glaucoma and ocular hypertension, to investigate the effect of corneal thickness on pressure readings by both instruments, and to assess the reproducibility of dynamic contour tonometer.MethodsNCT and DCT measurements were made on 104 eyes of 104 patients with primary open-angle glaucoma (n=75) or ocular hypertension (n=29), and agreement was assessed by means of Bland–Altman plots. The effect of corneal thickness on both tonometers was assessed by linear regression analysis. Interobserver and intraobserver variations for dynamic contour tonometer were assessed in 41 eyes of 41 patients.ResultsThe mean difference±SD (95% limits of agreement) between NCT and DCT was −0.80±2.98 (−6.6 to 5.1) mm Hg (P=0.009) and no relation between NCT/DCT differences and average was found. The intraocular pressure readings obtained by noncontact tonometer depended on central corneal thickness (P<0.001, adjusted r2=0.301). However, dynamic contour tonometer readings showed no effect of corneal thickness (P=0.388, adjusted r2=−0.002). The coefficient of repeatability for DCT was 0.92 (95% CI 0.85–0.96, P=0.001).ConclusionIn subjects with primary open-angle glaucoma and ocular hypertension, NCT and DCT readings are not interchangeable. DCT measurements, unlike NCT measurements, did not depend on corneal thickness.

Cyclosporin effectively inhibits posterior capsule opacification after phacoemulsification in rabbits: a preliminary study

Purpose:  To evaluate whether cyclosporin A prevents or reduce posterior capsule opacification after phacoemulsification surgery in rabbit eyes.