Kemal Tekin

Effect of Pseudoexfoliation on Corneal Transparency.

Purpose: To perform a comparison of the corneal optical density (COD) parameters in eyes with pseudoexfoliation syndrome (PES) and age-matched controls. Methods: This study was designed as a prospective cross-sectional study. Pentacam HR-Scheimpflug imaging system was used to observe the COD of PES, normal fellow, and normal control eyes. Forty-two patients with unilateral PES and 40 age- and sex-matched normal subjects were included. Group 1 included eyes with PES, group 2 included the clinically unaffected fellow eyes, and group 3 included right eyes of healthy patients. Main outcome measures were densitometry values of the cornea. Results: There was no significant difference between groups in means of central corneal thickness (P > 0.05). Eyes of unilateral PES patients and eyes of controls differed in COD parameters. Mean total COD in group 1 eyes (21.9 ± 4.9) and group 2 eyes (21.95 ± 5.1) was higher than that in group 3 eyes (17.72 ± 4.7) (P < 0.0001). Conclusions: This research demonstrates that the presence of pseudoexfoliation material can cause decrease in the transparency of clear cornea.

Evaluation of the shifting of the line of sight and higher order aberrations of eyes with keratoconus after corneal cross-linking

AIM To evaluate changes in the coordinates of the line of sight (LoS) and higher order aberrations (HOAs) of eyes with keratoconus, following corneal cross-linking (CXL). METHODS All patients (93 eyes) underwent detailed ophthalmologic examination and Pentacam HR measurements at baseline and at 3, 6, and 12 months after corneal CXL. LoS coordinates on the horizontal (x) and vertical (y) axes, vertical coma, vertical trefoil, spherical aberration, total root-mean square (RMS), and HOA-RMS values were recorded along with visual acuity and topographical parameters. RESULTS LoS significantly shifted to the nasal region after corneal CXL in both right and left eyes (p=0.003 and p=0.01, respectively). Horizontal axis values of both eyes significantly shifted to the temporal region at postoperative 6th months compared to the baseline measurements (p=0.02 and p=0.02, respectively) and remained the same between postoperative 6th months and 12th months (p=1.00 and p=0.97, respectively). Total-RMS, HOA-RMS, vertical coma, and spherical aberration values significantly improved after corneal CXL (p<0.001, p=0.02, p=0.04, and p<0.001, respectively). The improvements in HOAs were significant at postoperative 6th months compared to the baseline measurements (p=0.003, p=0.02, p<0.001, and p=0.003, respectively) while remained the same between postoperative 6th months and 12th months (p>0.05 for all values). The changes in horizontal-axis coordinates in left eyes were significantly correlated with anterior elevation, anterior astigmatism, total-RMS and HOA-RMS changes (r2=0.20, p=0.03; r2=0.35, p<0.01; r2=0.50, p<0.001 and r2=0.35, p=0.004; respectively). CONCLUSIONS LoS significantly shifted to the nasal region and HOAs improved after corneal CXL and these changes stabilized 6th months after corneal CXL. It would be more better to perform refractive surgery in crosslinked corneas at least 6th months after corneal CXL.

Intravitreal Bevacizumab and Ranibizumab in the Treatment of Acute Central Serous Chorioretihopathy: A Single Center Retrospective Study

ABSTRACT Objectives: To evaluate and compare the anatomical and functional outcomes of patients with acute central serous chorioretinopathy (CSC) who did not receive any intervention or treatment with intravitreal bevacizumab or ranibizumab. Methods: A single-center retrospective comparative study. Seventy eyes of 70 patients were recruited for the study; 27 patients were only observed without any medication or intervention (observation group), 23 were treated with intravitreal bevacizumab (IVB group), and the remaining 20 were treated with intavitreal ranibizumab (IVR group). The best-corrected visual acuity (BCVA) and central macular thickness (CMT) obtained by spectral-domain optical coherence tomography were compared between the groups. Results: There were no significant differences between the groups with regard to age, sex, and follow-up periods (p>0.05). The mean time from baseline to initial complete resolution of subretinal fluid was 3.52±1.64 months in the observation group, 1.19±0.60 months in the IVB group, and 1.11±0.47 months in the IVR group; the resolution time was significantly longer in the observation group (p<0.001). While the CMT was significantly thicker in the observation group when compared to the IVB and IVR groups in the first month (p=0.001), it was similar between the groups in the third, sixth, and twelfth months (p>0.05). Additionally, pairwise comparisons of the IVB and IVR groups revealed that there were no significant differences between these groups regarding CMT at any follow-up time (p>0.05). Conclusions: Compared with observation alone, neither IVB nor IVR had a positive effect in terms of anatomical and functional outcomes for acute CSC. Although the resolution time of SRF is shorter by using ranibizumab, both the ranibizumab and bevacizumab could be effective in achieving rapid resolution of serous detachment in patients with acute CSC.

Comparison of Results of Accelerated Corneal Cross-Linking With Hypo-Osmolar Riboflavin Solution Performed on Corneas Thicker and Thinner Than 400 μm.

Purpose: To evaluate the effect of accelerated corneal cross-linking (CXL) according to corneal thickness in keratoconus. Methods: Patients undergoing corneal CXL (9 mW/cm2) with hypo-osmolar riboflavin solution were included in this study. The patients were divided into 2 groups. Group 1 included patients with corneal thickness below 400 &mgr;m (50 eyes from 45 patients), and group 2 included patients with corneal thickness above 400 &mgr;m (50 eyes from 47 patients). Visual acuity (VA), refraction, topographic values, and higher-order aberrations were evaluated in the preoperative term and postoperatively at months 1, 3, and 6. Results: The improvements in VA were significant and similar in both groups [0.25/0.19 logMAR, P = 0.130]. In group 1, the rate of decrease in spherical refraction [0.85/0.27 diopters (D), P = 0.012] and maximum keratometry (Kmax, 2.49/0.68 D, P < 0.001) was significantly higher than that in group 2. The cylindrical change was similar (0.43/0.29 D P = 0.173). Corneal thinning was higher in group 2 (25/40.4 &mgr;m P < 0.001). Anterior elevation values decreased at higher rates in group 1 (3.73/0.24 &mgr;m P < 0.001); neither group showed a significant difference in posterior elevation (−0.14/−0.4 &mgr;m P > 0.05). In group 1, all aberration values except trefoil significantly decreased, whereas in group 2 none of the aberrations decreased except the total root mean square. All higher-order aberration values decreased at significantly higher rates in group 1 (P < 0.05). Conclusions: In thin corneas, accelerated corneal CXL provides better anatomical changes; however, the improvement in VA is similar to that in thick corneas.

Quantitative evaluation of early retinal changes in children with type 1 diabetes mellitus without retinopathy: Posterior segment in type 1 diabetes Tekin, Inanc, Kurnaz et al.

To investigate whether abnormal glucose metabolism and duration of diabetes mellitus (DM) caused the thinning in retinal layers in children with type 1 DM without retinopathy by using spectral domain optical coherence tomography (SD‐OCT) and to compare the results obtained with those in healthy children.

Anatomical and functional outcomes of scleral buckling versus primary vitrectomy in pseudophakic retinal detachment

Retinal detachment is the separation of the sensory retina from the retinal pigment epithelium by subretinal fluid. There are several types of retinal re-attachment surgery, including scleral buckling (SB), pneumatic retinopexy, and vitrectomy (with or without SB). The objective of this study was to compare anatomical and visual outcomes between patients with pseudophakic rhegmatogenous retinal detachment (RRD) who underwent pars plana vitrectomy (PPV) with silicone oil (SO) or perfluoropropane (C3F8) gas tamponade and pseudophakic RRD patients who underwent SB surgery. We evaluated retrospectively 101 pseudophakic RRD patients from a single center. The patients were classified into three groups according to the surgical procedure performed: PPV + Silicone - patients who underwent PPV with SO tamponade; PPV + Gas - patients who underwent PPV with perfluoropropane gas tamponade; and SB group - patients who underwent SB surgery. The groups were compared with regard to primary and final anatomical and visual outcomes. The number of patients in PPV + Silicone, PPV + Gas, and SB group was 39 (38.6%), 32 (31.7%), and 30 (29.7%), respectively. The mean follow-up period in PPV + Silicone, PPV + Gas, and SB group was 33.95 ± 23.58, 32.62 ± 10.95, and 33.76 ± 16.62 months, respectively. No significant difference was observed between the groups neither with regard to primary and final anatomical and visual success rates nor in relation to the recurrence rate of retinal detachment. According to our anatomical and visual outcome results, either of the three methods (i.e., PPV + Silicone, PPV + Gas, or SB) can be used in the treatment of pseudophakic retinal detachment.

Effect of preoperative factors on visual acuity, corneal flattening, and corneal haze after accelerated corneal crosslinking

Purpose To evaluate the preoperative characteristics that might influence corneal flattening, visual acuity, and corneal haze after accelerated (9 mW/cm2) corneal collagen crosslinking (CXL). Setting Ulucanlar Eye Hospital, Ankara, Turkey. Design Retrospective case series. Methods Accelerated corneal CXL was performed in eyes with progressive keratoconus. Preoperative characteristics included age, sex, uncorrected distance visual acuity and corrected distance visual acuity (CDVA), maximum keratometry (K), corneal thickness, corneal hysteresis, the corneal resistance factor, cone location, and densitometry values. Regression analysis was performed to determine the predictive factors for accelerated corneal CXL outcomes. Results The study included 162 eyes of 146 patients with a mean age of 19.3 years ± 4.4 (SD). There was 0.20 logMAR improvement in CDVA (P = .011), 1.85 diopter flattening in maximum K (P < .001), and 5.84 grayscale unit increase in densitometry (P < .001) at 1 year. Multivariate analysis found that preoperative CDVA was a predictive factor for CDVA improvement (ß coefficient, 0.233; 95% confidence interval [CI], −0.054 to 0.477; P = .003). Preoperative maximum K was a predictive factor for corneal flattening (ß coefficient, 0.506; 95% CI, 0.185 to 0.681; P < .001). Univariate analysis found that preoperative densitometry was a predictive factor for increasing corneal densitometry (ß coefficient, 0.466; 95% CI, −0.122 to 0.683; P = .001) and corneal scar formation (ß coefficient, 0.256; 95% CI, 0.012 to 0.421; P = .041). Conclusions Patients with a worse preoperative CDVA and higher maximum K were most likely to have improvement after accelerated CXL. Patients with high preoperative densitometry were most likely to have scar formation after the procedure. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.

Goldmann-Favre Syndrome: Case Series

Goldmann-Favre syndrome, which is caused by mutation of the NR2E3 gene, is a retinal degenerative disease with a wide spectrum of phenotypic properties. Variations in clinical presentation result in difficulties in differential diagnosis. In this article, Goldmann-Favre syndrome cases with different clinical findings are presented. Clinical characteristics of our cases were reviewed and discussed in light of the literature.

The significance of thiol/disulfide homeostasis and ischemia-modified albumin levels to assess the oxidative stress in patients with different stages of diabetes mellitus

Abstract This study investigated the value of Thiol/Disulfide homeostasis and ischemia-modified albumin (IMA) levels in discriminating diabetic cases with different stages of retinopathy and without retinopathy. In total, 122 patients with type 2 diabetes mellitus (DM) were enrolled in this prospective cross-sectional study. These patients were separated into three subgroups: Group 1 included 42 patients with DM and no diabetic retinopathy (DR), Group 2 included 40 patients with DM having non-proliferative DR and the Group 3 had 40 patients with DM having proliferative DR. The native thiol, total thiol, and disulfide levels and disulfide–native thiol, disulfide–total thiol, and native thiol–total thiol ratios as well as the IMA levels were analyzed and compared among the groups. There were no statistically significant differences regarding the ages and genders of the patients between the groups. The native thiol level, the total thiol level and the native thiol–total thiol ratio showed a statistically significantly reduction, while the disulfide level, the disulfide–native thiol ratio, and the disulfide–total thiol ratio showed a statistically significantly elevation in the Group 3 compared with the Group 1 and Group 2. Additionally, the mean IMA levels were statistically significantly higher in Group 3 when compared to Group 1 and Group 2 (p = .003 and p = .014, respectively). In conclusion, both Thiol/Disulfide homeostasis parameters and IMA levels increase with the progression of DR. Thiol/Disuldife homeostasis balance and IMA levels may be used a biomarker to monitor the tissue ischemia in DM and to discriminate the different stages of DR, in the future.

Electron microscopic evaluation of anterior lens epithelium in patients with idiopathic congenital cataract

PurposeTo investigate the ultrastructure of the lens epithelial cells (LECs) in patients with idiopathic congenital cataract.MethodsThis is a prospective interventional study. The anterior lens capsules (aLC: basement membrane and associated LECs) were taken from 16 eyes of 12 consecutive patients who were diagnosed as having idiopathic congenital cataracts. The aLCs were obtained from cataract surgery and prepared for transmission electron microscopy (TEM).ResultsSome significant ultrastructural changes were observed in all aLCs of the participants. The anterior LECs showed alterations in different areas which were partly cuboidal and partly squamous in shape. The LECs had euchromatic nucleus and included some vacuoles in the cytoplasms as a remarkable alteration. The sizes of these intraepithelial cell vacuoles were changeable.ConclusionsWe identified remarkable changes in LECs of the eyes with idiopathic congenital cataract by TEM. It can be assumed that oxidative damage may be associated with these ultrastructural changes in LECs of the eyes with idiopathic congenital cataracts.