Mahmut Kaya

Long-term success of ahmed glaucoma valve in refractory glaucoma

AIM To evaluate the long-term results and complications of ahmed glaucoma valve (AGV) implantation in refractory glaucoma. METHODS A retrospective review of 13 patients (13 eyes) with refractory glaucoma who underwent AGV implantation and had a minimum follow-up of 18 months was performed. All patients underwent a complete ophthalmologic examination and intraocular pressure (IOP) measurement before surgery and at 1 month, 3 months, 6 months, 1 year after surgery and yearly afterwards. Complications and the number of antiglaucoma medications needed were recorded. RESULTS Mean age was 27.3±16.0 years. All eyes (100%) had at least one prior incisional surgery. Mean follow-up was 61.3±30.8 months. IOP was reduced from a mean of 35.0 ±7.0mmHg to 18.2±7.9mmHg at 12 months and to 17.0±4.1mmHg at 96 months (P<0.05) with a lower number of medications from baseline, 76.9% patients required additional procedures to achieve the success criteria set by previously published series. The most common complications were encapculated cyst formation in eight eyes (61.5 %) and tube exposure in four eyes (30.8%). CONCLUSION Encapsulated cyst formation was the most common complication which hindered succesful IOP control after AGV implant insertion for refractory glaucoma. Despite cyst excision with anti-fibrotic agents, successful IOP reduction was not achieved in 76.9% of the patients without antiglaucoma medication.

Associations of VEGF/VEGF-Receptor and HGF/c-Met Promoter Polymorphisms With Progression/Regression of Retinopathy of Prematurity

Purpose: To determine the effect(s) of vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), hepatocyte growth factor (HGF), and HGF receptor (c-Met) polymorphisms on progression/regression of retinopathy of prematurity (ROP) in premature infants. Materials and methods: This study comprised both a prospective analysis and a clinically relevant laboratory investigation. Enrolled were 123 Turkish preterm infants—gestational age (GA), ≤34 weeks; birth weight (BW), ≤1500 g—from a single tertiary care center. Infants were grouped as those who had undergone laser therapy (Group 1, n = 42), those with spontaneously regressed ROP (Group 2, n = 50), and those with no ROP (controls) (Group 3, n = 31). VEGF −634 C and VEGF −460 C polymorphisms were analyzed using the PCR-restriction fragment length polymorphism (RFLP) (PCR-RFLP) technique. VEGFR-2, HGF, and c-Met gene promoter polymorphisms were determined by direct sequencing. Results: Mean GAs and BWs of infants in Groups 1 and 2 were statistically significantly lower than those of Group 3 (p = 0.001). Frequencies of VEGF −634 C and VEGF −460 C polymorphisms were similar for all groups. We found a +32G→A single-nucleotide polymorphism (SNP) in the promoter region of the VEGFR-2 gene. HGF and c-Met gene promoter polymorphisms were not found in any group. Conclusions: Our results indicate that there is no association between the carrier states of gene promoter polymorphisms VEGF −634 C, VEGF −460 C, and VEGFR-2, and progression or spontaneous regression of ROP in preterm infants. The absence of HGF and c-Met polymorphisms in our study groups suggests that polymorphisms in the minimal promoters of these genes are not involved in the pathogenesis of ROP.

The Evaluation of Choroidal Vascular Changes Associated with Vascular Dysregulation in Patients with Multiple Sclerosis Using Enhanced Depth Imaging Optical Coherence Tomography

Purpose: To evaluate the choroidal thickness (CT) in patients with Multiple Sclerosis (MS) using enhanced depth imaging optical coherence tomography (EDI-OCT) and comparing it with healthy subjects. Material/Methods: Sixty-four eyes of 32 patients with MS (22 women, 10 men, mean age: 37.5 ± 8.21 years) were enrolled in this study. Their choroidal thickness was measured using EDI-OCT, and compared with healthy subjects. CT was measured at fovea and at four extrafoveal points. Results: The mean subfoveal choroidal thickness was 327.01 ± 64.60 μm in MS patients and 365.3 ± 99.14 μm in controls ( p=0.019 ). Significant differences were found at points temporal 500 μm, temporal 1000 μm and nasal 500 μm to the fovea between patients and control group ( p=0.018, 0.003 and 0.03, respectively). Conclusions: Patients with MS had thinner choroids when compared to normal subjects. The decrease in mean choroidal thickness in MS patients compared to controls may be related to vascular dysregulation or inflammatory pathology of MS. Further prospective studies are needed to evaluate the choroidal thickness in MS patients.

Evaluation of Macular Perfusion in Healthy Smokers by Using Optical Coherence Tomography Angiography

BACKGROUND AND OBJECTIVE To investigate the macular perfusion changes in healthy smokers by using optical coherence tomography angiography (OCTA). PATIENTS AND METHODS OCTA measurements were taken for the right eyes of 40 smokers (Group 1) and age- and sex-matched control cases (Group 2). Group 1 underwent OCTA scanning with the XR Avanti AngioVue OCTA (Optovue, Fremont, CA) at baseline and at 5 minutes, 30 minutes, and 60 minutes after one standard cigarette smoking. The same scanning protocol was applied without smoking in Group 2. Macular vessel area density, flow index of the choriocapillaris, foveal avascular zone (FAZ), and central macular thickness were evaluated in both groups. RESULTS Group 1 consisted of 28 men and 12 women with a mean age of 41.2 years ± 9.1 years (range: 24 years to 63 years). The mean age of Group 2 was 42.6 years ± 8.4 years (range: 21 years to 65 years), which consisted of 28 men and 12 women. The mean baseline vessel area density, flow index of the choriocapillaris, FAZ, and central macular thickness showed no statistically significant differences between Groups 1 and 2. Although the flow index of choriocapillaris values were similar at the repetitive OCTA measurements in the control group (P > .05), it was decreased from 1.94 ± 0.06 to 1.89 ± 0.08, 1.90 ± 0.08, and 1.91 ± 0.07 at 5 minutes, 30 minutes, and 60 minutes following smoking, respectively, in Group 1 (P < .001). CONCLUSION Smoking causes a significant decrease in the blood flow index of the choriocapillary area by the acute effects of nicotine and other chemical substances in cigarettes on peripheral vascular structure, as evaluated by OCTA. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:617-622.].

Comparison of macular pigment optical density in patients with dry and wet age-related macular degeneration

Aim: The aim of the study was to evaluate the macular pigment optical density (MPOD) levels in patients with wet age-related macular degeneration (AMD), dry AMD, and also in healthy controls. Settings and Design: This study was conducted at Department of Ophthalmology, and the study design was a prospective study. Patients and Methods: Forty-eight patients with wet AMD, 51 patients with dry AMD, and 50 controls were included in the study. All patients were naive to both previous lutein or zeaxanthin administration and any previous intravitreal injections. Fundus reflectance (VISUCAM 500, reflectance of a single 460 nm wavelength) was used to measure the MPOD levels. Three groups were compared regarding age, gender, serum lutein, and zeaxanthin concentrations as well as MPOD levels. Results: Serum lutein and zeaxanthin levels were significantly higher in control group when compared with wet AMD (Group 1) and dry AMD (Group 2) (P = 0.001 and P< 0.001, respectively). Mean MPOD was found to be similar in all of the three study subgroups (P = 0.630). However, maximum MPOD was significantly higher in control group when compared with Group 1 and 2 (P = 0.003). There was no correlation between serum lutein or zeaxanthin concentrations and mean MPOD levels (P = 0.815, r = 0.014 and P = 0.461, r = 0.043, respectively), but there was a weak correlation between serum zeaxanthin concentration and maximum MPOD level (P = 0.042, r = 0.124). Maximum MPOD level was found to be correlated with the level of AMD (Group 1, 2, and 3; r = 0.184, P = 0.041). Conclusion: Maximum MPOD level was found to be lower in patients with AMD when compared with control cases. Mean MPOD and maximum MPOD levels were similar in wet and dry AMD Groups. These results can be applied clinically keeping in mind that MPOD measurements with one wavelength reflectometry may not be completely reliable.

Corneal Biomechanical Properties in Patients With Arcus Senilis.

Purpose: To compare the corneal biomechanical properties and intraocular pressure (IOP) levels in patients with and without arcus senilis (AS). Methods: Ocular response analyzer measurements were performed on the right eyes of 37 patients with AS (group 1) and 37 control eyes (group 2). Corneal hysteresis, corneal resistance factor, Goldmann-correlated IOP, and corneal compensated IOP were recorded with Ocular response analyzer. Spherical equivalent value of the refractive errors, axial length, central corneal thickness, and IOP measured with Goldmann applanation tonometer were noted for each study eyes. Statistical analyses were performed with Student t, Kruskal–Wallis, and Pearson correlation tests. Results: Mean age was 67.6 ± 9.8 years in group 1 and 65.3 ± 8.1 years in group 2 (P = 0.308). Mean corneal hysteresis and corneal resistance factor readings were 9.8 ± 0.9 versus 10.6 ± 0.8 (P < 0.001) and 10.05 ± 1.07 versus 10.9 ± 0.9 (P < 0.001) in groups 1 and 2, respectively. Mean corneal compensated IOP and Goldmann-correlated IOP values were found as 16.1 ± 3.3 mm Hg versus 15.8 ± 2.6 mm Hg (P = 0.719) and 15.1 ± 3.3 mm Hg versus 15.0 ± 2.6 mm Hg (P = 0.912) in groups 1 and 2, respectively. There was no statistical difference in IOP measured with Goldmann applanation tonometer, central corneal thickness, spherical equivalent value of the refractive error, axial length measurements, and mean keratometry readings between the 2 groups (P = 0.983, P = 0.289, P = 0.938, P = 0.886, P = 0.07, respectively). Conclusions: The mean corneal hysteresis and corneal resistance factor values of eyes with AS were lower when compared with the controls. This study demonstrated that AS may change the corneal biomechanical properties.

Evaluation of inner segment/outer segment junctions in different types of epiretinal membranes.

Purpose: This study was conducted to evaluate the relationships of inner/outer segment (IS/OS) junction disruption, macular thickness, and epiretinal membrane (ERM) grade with best-corrected visual acuity (BCVA), as well as the relationship between IS/OS junction disruption and ERM grade. Methods: Fifty-four eyes of 54 patients with different grades of ERM were retrospectively reviewed. Patients were classified into three groups by ERM grade according to retinal striae and vessel distortion: grade/group 1, visible membranes without retinal striae or vessel distortion; grade/group 2, mild to moderate macular striae or vessel straightening; and grade/group 3, moderate to severe striae and vascular straightening. Correlations of BCVA with age, central retinal thickness, ERM grade, and IS/OS disruption as well as of IS/OS disruption, central macular thickness, and BCVA with ERM grade were evaluated. Results: Twenty-nine (53.7%) eyes exhibited IS/OS junction disruption. Groups 1 and 2 differed significantly with respect to BCVA (p=0.038), but groups 2 and 3 did not (p=0.070). Central macular thickness was significantly greater in group 2 than in group 1 (p=0.031) and in group 3 than in group 2 (p=0.033). Groups 1 and 2 differed significantly in terms of IS/OS disruption (p=0.000), but groups 2 and 3 did not (p=0.310). Conclusions: The IS/OS junction appears to be disrupted during the early stages of ERM. Grade 3 ERM is associated with a significantly higher incidence of IS/OS disruption.

Combined transscleral fixation of an artificial iris prosthesis with an intraocular lens

Post-traumatic aniridia combined with aphakia may be seen after globe injury. Aside from esthetic aspects, partial or total loss of the iris tissue may also be related to various degrees of glare and photophobia. Such patients suffer from severe visual impairment secondary to aphakia. Herein we describe a novel surgical technique for the management of an aphakic eye with traumatic aniridia for a patient who underwent transscleral fixation of a custom-tailored artificial iris prosthesis combined with a rigid intraocular lens (IOL). Tight suturing of the IOL haptic eyelets on the silicone iris prosthesis and fixation of such a complex to the scleral wall may provide excellent cosmetic and functional outcomes in aphakic eyes with aniridia.

Is There a Relationship Between Use of Anti-Vascular Endothelial Growth Factor Agents and Atrophic Changes in Age-Related Macular Degeneration Patients?

Choroidal neovascularization due to age-related macular degeneration (AMD) is currently treated successfully with anti-vascular endothelial growth factor (VEGF) intravitreal agents. Emerging evidence suggests that anti-VEGF treatment may potentially increase development of geographic atrophy. However, there is not yet direct proof of a causal relationship between geographic atrophy and use of anti-VEGF agents in neovaskuler AMD. The aim of this review is to discuss the evidence concerning the association between anti-VEGF therapy and progression of geographic atrophy.

A Novel Biomarker in Diabetic Macular Edema with Serous Retinal Detachment: Serum Chitinase-3-Like Protein 1

Purpose: To determine whether serum chitinase-3-like protein 1 (CHI3L1) and interleukin-6 (IL-6) levels correlate with serous retinal detachment (SRD) in diabetic macular edema (DME) using spectral-domain optical coherence tomography (SD-OCT). Methods: In this cross-sectional case-control study, 394 patients (treatment-naive DME patients, n = 218; diabetic patients without DME, n = 96; nondiabetic controls, n = 80) were included in the study. Eyes were classified according to SD-OCT features of DME: SRD, cystoid macular edema (CMO), and diffuse retinal thickness (DRT). Serum concentrations of CHI3L1 and IL-6 were analyzed using enzyme-linked immunosorbent assay. Results: Serum CHI3L1 and IL-6 levels were significantly higher in DME with SRD compared to patients with CMO and DRT (p < 0.001 for all groups). Multivariate regression analysis showed that CHI3L1 and IL-6 had a stronger influence on the presence of SRD in DME (r = 1.162, p = 0.026, and r = 1.242, p = 0.016, respectively). Serum concentration of CHI3L1 was significantly correlated with that of IL-6 (r = 0.386, p = 0.0015). Conclusions: Our data suggest that serum concentrations of CHI3L1 and IL-6 are involved in the process of SRD in DME. CHI3L1 can be investigated further as a new diagnostic biomarker for DME with SRD.