Ebru Gorgun

Corneal biomechanical properties and intraocular pressure changes after phacoemulsification and intraocular lens implantation

PURPOSE: To evaluate corneal viscoelastic and intraocular pressure (IOP) changes measured by an ocular response analyzer (ORA) after phacoemulsification and intraocular lens (IOL) implantation. SETTING: Yeditepe University Department of Ophthalmology, Istanbul, Turkey. METHODS: Fifty‐one eyes scheduled for cataract surgery were included in the study. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal‐compensated intraocular pressure (IOPcc), and Goldmann‐correlated IOP (IOPg) were measured by ORA preoperatively and 1 week and 1 and 3 months postoperatively. Central corneal thickness (CCT) was measured using the ORAs integrated handheld ultrasonic pachymeter. RESULTS: The mean preoperative CCT (537 μm ± 46 [SD]) did not change significantly by the end of 1 month postoperatively. The mean preoperative IOPcc (17.2 ± 3.0 mm Hg) decreased significantly by 3 months postoperatively (15.2 ± 3.7 mm Hg) (P = .018). The mean CH decreased from 10.36 ± 1.48 mm Hg preoperatively to 9.64 ± 1.26 mm Hg at 1 week (P = .028); it increased to preoperative values at the end of 1 month (10.20 ± 1.70) and 3 months (10.74 ± 1.54) (P>.05). The mean CRF decreased from 10.94 ± 2.54 mm Hg preoperatively to 9.99 ± 1.77 at 1 week (P = .026); it increased to preoperative values at 1 month (10.26 ± 1.59) and 3 months (10.35 ± 1.46) (P>.05). CONCLUSIONS: Although CH and the CRF decreased in the early postoperative period, the parameters increased and reached preoperative values by 3 months postoperatively, showing that corneal biomechanical properties are influenced by phacoemulsification and IOL implantation.

Glutathione S transferase M1 and T1 genetic polymorphisms are related to the risk of primary open-angle glaucoma: a study in a Turkish population.

Background: Genetic factors and oxidative damage have been shown to have a role in the development of primary open angle glaucoma (POAG). Aim: To determine the effects of genetic polymorphisms of glutathione S transferase (GST)M1 and GSTT1 on the risk of POAG in a Turkish population. Methods: Using a multiplex polymerase chain reaction (PCR), GSTM1 and GSTT1 gene polymorphisms were analysed in 144 patients with POAG and in 121 otherwise healthy controls of similar age. Results: The GSTM1 positive genotype and the GSTT1 null genotype had an increased risk of developing POAG (p<0.001, OR 2.93, 95% CI 1.66 to 5.20 and OR 4.25, 95% CI 2.30 to 7.80, respectively). The risk of glaucoma also increased significantly in subjects with a combination of GSTM1 positive and GSTT1 null genotypes (p<0.001, OR 3.46, 95% CI 1.64 to 7.38). Conclusion: The GSTM1 positive genotype and GSTT1 null genotype or the combination of both may be associated with the increased risk of development of POAG in the Turkish population.

Anterior segment optical coherence tomography measurement of anterior chamber depth and angle changes after phacoemulsification and intraocular lens implantation.

PURPOSE: To use anterior segment optical coherence tomography (AS‐OCT) to evaluate anterior chamber depth (ACD) and angle after phacoemulsification and intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, Yeditepe University, Istanbul, Turkey. METHODS: Forty‐seven eyes (37 patients) had uneventful phacoemulsification and IOL implantation through a clear corneal incision. Anterior segment OCT was performed preoperatively and 1 week and 1 month postoperatively. The angle‐referenced (ACD1), pupil‐referenced (ACD2), and lens‐referenced (ACD3) ACDs, crystalline lens rise (CLR), pseudophakic posterior chamber depth (PPCD), and nasal and temporal iridocorneal angles were measured. Statistical analysis was by a 1‐way analysis of variance and Pearson correlation analysis. RESULTS: The mean age of patients was 70 years ± 10.17 (SD). The mean ACD1 (mean increase) was 3.06 ± 0.25 mm preoperatively, 3.16 ± 0.22 mm at 1 week (0.1 mm), and 3.16 ± 0.19 mm at 1 month (0.1 mm); the mean ACD2, 2.76 ± 0.47 mm preoperatively, 3.62 ± 0.24 mm at 1 week (0.86 mm), and 3.63 ± 0.20 mm (0.87 mm) at 1 month; and the mean ACD3, 2.54 ± 0.46 mm preoperatively, 3.97 ± 0.28 mm at 1 week (1.43 mm), and 3.91 ± 0.25 mm at 1 month (1.37 mm). The mean CLR was 0.497 ± 0.363 mm and the mean PPCD, 0.322 ± 0.150 mm. The increase in nasal and temporal iridocorneal angles was statistically significant at both postoperative examinations (P<.01). CONCLUSION: Deepening of the anterior chamber and widening of the nasal and temporal angles after cataract extraction was shown on AS‐OCT.

Polymorphisms of the DNA repair genes XPD and XRCC1 and the risk of age-related macular degeneration.

PURPOSE Oxidative stress seems to be an important factor in the development of age-related macular degeneration (AMD). The role of DNA repair mechanisms has also received attention recently in AMD pathogenesis. This case-control study was conducted to determine the frequency of polymorphisms in two DNA repair enzyme genes, xeroderma pigmentosum complementation group D (XPD), codons 312 and 751, and x-ray cross-complementing group 1 (XRCC1), codons 194 and 399, in patients with AMD and in disease-free control subjects. METHODS Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to analyze XPD Asp312Asn and Lys751Gln and XRCC1 Arg194Trp and Arg399Gln in 120 patients with AMD (65 with dry type and 55 with wet type) and in age-matched 205 disease-free control subjects. RESULTS Genotypic and allelic distributions of the polymorphisms were detected. For the XPD polymorphism, although the allele frequencies were not different between the patients and healthy control subjects, there was a significant difference between frequencies for the XPD751 Gln/Gln genotype in AMD patients (9%) and healthy control subjects (19%; P=0.02). The XPD751 Gln/Gln genotype seemed to have a protective effect against development of AMD (odds ratio, 0.41; 95% confidence interval, 0.19-0.88). Stratification by subtype of AMD revealed that the XPD751 Gln/Gln genotype was significantly lower only in the patients with dry type (P=0.02). These interactions remained nearly significant after Bonferroni correction (P<0.0125). Haplotype analysis for the two XPD polymorphisms revealed that the haplotype GC (312Asp-(751)Gln) was a protective haplotype against AMD. No statistically significant difference was found for the genotypic and allelic distributions of the polymorphisms in the XRCC1 gene between the patients and the control subjects. CONCLUSIONS Polymorphism in XPD codon 751 may be associated with the development of AMD.

Assessment of Anterior Chamber Depth Using Visante Optical Coherence Tomography, Slitlamp Optical Coherence Tomography, IOL Master, Pentacam and Orbscan IIz

Aims: To assess and compare the anterior chamber depth (ACD) by different anterior segment imaging techniques. Methods: Eighty healthy eyes of 40 patients were recruited, and 3 consecutive measurements of ACD were determined prospectively utilizing Visante optical coherence tomography (OCT), slitlamp (SL) OCT, IOL Master, Pentacam and Orbscan IIz. The statistical significance of interdevice differences between measurements was evaluated by one-way ANOVA and Bland-Altman analysis. The repeatability of 3 consecutive measurements was analyzed by repeated-measures ANOVA. Results: The mean ACD was 2.98 ± 0.29, 2.85 ± 0.29, 3.33 ± 0.42, 2.93 ± 0.30 and 2.80 ± 0.29 mm with Visante OCT, SL-OCT, IOL Master, Pentacam and Orbscan IIz, respectively. All devices displayed a high intrasession repeatability (repeated-measures ANOVA, p > 0.05). ACD measurements obtained by the IOL Master were significantly greater compared to other devices. ACD values detected by Visante OCT and SL-OCT, Pentacam and Orbscan IIz were not clinically interchangeable, even though no statistically significant difference was detected. Conclusion: Although noncontact ACD measurements using all modalities were easy to handle and demonstrated good repeatability, the tested devices were not regarded as compatible. Hence, the clinician should take the different modalities into consideration during ACD assessment using various devices.

Glutathione S-Transferase M1, GSTT1 and GSTP1 Genetic Polymorphisms and the Risk of Age-Related Macular Degeneration

Purpose: To determine the possible effects of glutathione S-transferase (GST) M1, GSTT1 and GSTP1 genetic polymorphisms on the risk of developing age-related macular degeneration (AMD). Patients and Methods: This case-control study included a total of 120 patients with AMD (65 with dry-type AMD and 55 with wet-type AMD) and 198 disease-free controls. GSTM1 and GSTT1 polymorphisms were analyzed by using a multiplex polymerase chain reaction (PCR), and GSTP1 polymorphism was detected by real-time PCR assay. Results:GSTM1-null genotype was significantly associated with the development of AMD (p = 0.01, OR = 1.82, 95% CI = 1.14–2.91). Stratification by AMD subtypes revealed a significant relationship between GSTM1-null genotype and dry-type AMD (p = 0.02, OR = 1.98, 95% CI = 1.10–3.53). In a stepwise regression model, only GSTM1-null genotype was significantly associated with the development of AMD (p = 0.01, OR = 1.77, 95% CI = 1.11–2.81). Conclusions: Our findings suggest that genetic polymorphisms of GST may have a role in the development of AMD.

Fundus autofluorescence in acute and chronic central serous chorioretinopathy

Background:  A prospective evaluation of the pattern of fundus autofluorescence in cases of acute versus chronic central serous chorioretinopathy (CSR).

A case of sterile endophthalmitis after repeated intravitreal bevacizumab injection.

PURPOSE The aim of this study was to describe a case of sterile endophthalmitis after repeated intravitreal bevacizumab injections for the treatment of choroidal neovascularization secondary to angioid streaks. METHODS This study was done as a case report. RESULTS A 57-year-old man who received a third injection of intravitreal bevacizumab for the treatment of choroidal neovascularization owing to angioid streaks developed sterile endophthalmitis. The patients condition improved after hourly topical steroid and antibiotic drops without a sequele. CONCLUSIONS The intravitreal injection of bevacizumab has the potential for the development of sterile endophthalmitis. The patients should be warned against this possible adverse reaction, especially after repeated injections.

Assessment of macular function by microperimetry in intermediate age-related macular degeneration

Purpose To evaluate retrospectively macular function by microperimetry (MP) in intermediate age-related macular degeneration (AMD). Methods Thirty eyes of 30 patients with intermediate AMD and a visual acuity of 20/32 or better were enrolled in the study. Macular function in patients with intermediate AMD and age-matched control group were carried out with MP1 microperimeter. Mean sensitivity (MS), mean defect (MD) parameters, fixation patterns, and localizations were evaluated. Mann-Whitney U test was used for the comparison of macular function parameters between the intermediate AMD group and the control group. Results MS was 12.7±2.8 dB and MD was detected as −6.2±2.2 dB in the intermediate AMD group by MP. Fixation patterns were stable in 22 eyes, relatively unstable in 7 eyes, and unstable in 1 eye. Fixation location was predominantly central in 19 eyes, poor central in 5 eyes, and predominantly eccentric in 6 eyes. In the control group MS was 18.0±0.6 dB and MD was −1.9±0.6 dB. When compared with control group, the decrease in MS and the increase in MD were statistically significant in the intermediate AMD group (p=0.001 and p=0.001, respectively). Conclusions Assessment of retinal sensitivity with MP1 microperimeter is a rapid, safe and noninvasive diagnostic method. Early macular function loss in intermediate AMD can be precisely detected by MP1 microperimeter before significant visual impairment is established and it is also useful for demonstrating the shift in the localization and the stability of fixation prior to progression of intermediate AMD to advanced and exudative stage.

Changes in corneal biomechanics in patients with keratoconus after penetrating keratoplasty.

Purpose: To examine the biomechanical properties of keratoconic eyes following penetrating keratoplasty and to compare results with the biomechanical characteristics of manifest keratoconus, forme fruste keratoconus and normal eyes as measured with the Reichert ocular response analyzer (ORA). Methods: This retrospective analysis comprised a total of 169 eyes: 34 eyes with forme fruste keratoconus (group FF), 36 eyes with manifest keratoconus (Group KC), 36 eyes that have undergone penetrating keratoplasty (Group PK) and a control group of 63 normal eyes (Group N). Corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure, and Goldmann correlated intraocular pressure were measured by ORA. Central corneal thickness was calculated by the integrated handheld ultrasonic pachymeter of the ORA. The statistical analysis focused on CH and CRF changes among the 4 groups. Results: When compared with normal eyes, mean CH and CRF values were found significantly lower in all groups (P < 0.05). Mean CH values were 8.19 ± 1.49 mm Hg in Group KC, 9.21 ± 1.38 mm Hg in Group FF, 10.16 ± 1.93 mm Hg in Group PK, and 11.43 ± 1.52 mm Hg in normal eyes (Group N). Although there was not a significant difference in mean CH values between Groups PK and FF (P = 0.072), the difference was significant between Groups KC as well as FF and Groups KC and PK (P < 0.05). Mean CRF values were found as 6.79 ± 1.81 mm Hg (Group KC), 8.21 ± 1.64 mm Hg (Group FF), 9.94 ± 2.34 mm Hg (Group PK), and 11.53 ± 1.83 mm Hg in Group N. The difference was statistically significant among all groups (P < 0.05). Conclusions: Penetrating keratoplasty has a beneficial effect on corneal biomechanics in keratoconic eyes. CH and CRF parameters approach the range of normal eyes after corneal transplantation.