Fatma Yülek

Macula and retinal nerve fiber layer in migraine patients: analysis by spectral domain optic coherence tomography.

Abstract Aim: Investigating the retinal nerve fiber layer (RNFL), macular and ganglion cell complex thickness in eyes of migraine patients using optical coherence tomography. Methods: The study was designed as an observational cross-sectional study. 50 patients with migraine (30 patients with aura and 20 patients without aura) and 50 healthy volunteers were included. Optical coherence tomography was performed with Optovue technology. The fast RNFL thickness (3.4) scan, MM5, and GCC acquisition protocols were used. Results: There was no statistically significant difference in retinal thickness in any of the quadrants between the control group and the migraine patients (p > 0.05). The average RNFL thickness (110.50 vs 102.84 microns, p = 0.03) was significantly thinner in migrainers as compared to the control. The ANOVA did not reveal any significant difference between migrainers with aura, migrainers without aura, and the control group. The VAS (visual analogue scale) score of migraine patients was not statistically significantly correlated with any of the parameters, while the length of migraine history was negatively correlated with the average RNFL thickness (r = −0.32, p = 0.03). Conclusıon: The average RNFL thickness in the migraine patients was found to be thinner than that in the control group. In addition, we found a negative weak correlation between length of migraine history and the average RNFL thickness, supporting the possible association between these pathologies.

Oxidative Stress and Anti-oxidative Defence in Patients with Age-related Macular Degeneration

Abstract Purpose: To evaluate the oxidative stress status and anti-oxidative defence in patients with age-related macular degeneration (AMD). Methods: A total of 22 patients diagnosed with AMD and 23 age-matched healthy controls were included in the present study. Serum levels of total oxidant status (TOS), total antioxidant status (TAS), total thiol status (TTS) and paraoxonase 1 (PON1) activity were investigated from samples. Results: Significant increase in TOS levels were observed in sera of AMD patients (25.3 ± 12.8) compared to controls (15.0 ± 4.4). TTS (404.3 ± 55.3) and serum PON1 enzyme activities (163.0 ± 65.5) were significantly lower in AMD patients (594.0 ± 64.2) relative to control groups (252.8 ± 132.7). Conclusion: The results of the present study show that there is a significant increase in oxidative stress in AMD patients and significant decrease in antioxidant defence, in the total thiol level and in PON1 activity in AMD patients compared with controls. The increased oxidative stress and decreased antioxidant levels may have a synergistic role in AMD development.

Impaired Corneal Biomechanical Properties and the Prevalence of Keratoconus in Mitral Valve Prolapse

Objective. To investigate the biomechanical characteristics of the cornea in patients with mitral valve prolapse (MVP) and the prevalence of keratoconus (KC) in MVP. Materials and Methods. Fifty-two patients with MVP, 39 patients with KC, and 45 control individuals were recruited in this study. All the participants underwent ophthalmologic examination, corneal analysis with the Sirius system (CSO), and the corneal biomechanical evaluation with Reichert ocular response analyzer (ORA). Results. KC was found in six eyes of four patients (5.7%) and suspect KC in eight eyes of five patients (7.7%) in the MVP group. KC was found in one eye of one patient (1.1%) in the control group (P = 0.035). A significant difference occurred in the mean CH and CRF between the MVP and control groups (P = 0.006 and P = 0.009, resp.). All corneal biomechanical and topographical parameters except IOPcc were significantly different between the KC-MVP groups (P < 0.05). Conclusions. KC prevalence is higher than control individuals in MVP patients and the biomechanical properties of the cornea are altered in patients with MVP. These findings should be considered when the MVP patients are evaluated before refractive surgery.

Choroidal Changes and Duration of Diabetes

Abstract Purpose: We investigate changes in macular choroidal thickness in eyes without diabetic retinopathy of patients with various durations of diabetes, using enhanced depth imaging optical coherence tomography (EDI OCT). Methods: The 134 Type-2 diabetic patients who presented without diabetic retinopathy were prospectively imaged using EDI OCT on Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany) sd-OCT. The patients with diabetes were classified into three groups, according to the duration of diabetes: Group I (5–9 years, n = 63); Group II (10–14 years, n = 37); Group III (15–40 years, n = 34). The retinal and choroidal thickness was evaluated between these groups at central fovea and at the regions at 500-mm intervals up to 1500 mm temporal and nasal to the fovea. Results: The central foveal retinal thickness was significantly different between groups (group I: 273.05 ± 19.51 µ, group II: 267.12 ± 20.78 µ, group III: 261.34 ± 22.27 µ; p = 0.04). The choroidal thickness measurements at central fovea, at 500, 1000, and 1500 micron intervals temporal and nasal to the center of the fovea were not significantly different between groups. The duration of diabetes was weakly correlated with choroidal thickness in all measured distances and they were not statistically significant. The central foveal choroidal thickness was weakly correlated with serum creatinine (r = −0.18, p = 0.03). Conclusıon: Foveal retinal thickness was significantly decreased in patients with longer duration of diabetes. Duration of diabetes does not seem to be related to foveal chorodial thickness. On the other hand, the weak relation between creatinine and choroidal thickness may be evaluated further. The choroidal thickness changes that may be an early sign of nephropathy can be submitted to an easy, noninvasive scanning test at the same time.

Comparison of the Pupillometry During Videonystagmography in Asymmetric Pseudoexfoliation Patients

Purpose: We aimed to evaluate the dynamic function of iris muscle in asymmetric pseudoexfoliation patients by videonystagmography. Methods: 15 patients with asymmetric pseudoexfoliation and 15 control subjects were included. The function of iris muscle was assessed by the pupillometry test of the videonystagmography by calculating the percent of change in pupillary diameter in unit time during fixation to an accommodative target, light reaction, convergence, and divergence. Results: There were significant differences between groups in the reaction during fixation (p: 0.01), in light reaction (p: 0.014), and in divergence-induced mydriasis (p: 0.003). In all of these, the difference between control eyes and pseudoexfoliative eyes of patients with PXS was significant. Conclusions: Pupillometry seems to be a promising noninvasive method to detect the clinical signs of PXS and may be useful for an accurate diagnosis.

Can Corneal Biomechanical Properties Give Clues About Elasticity of Optic Nerve Scleral Component in Nonarteritic Anterior Ischemic Optic Neuropathy

Objective: To investigate corneal biomechanical properties among individuals with unilateral nonarteritic anterior ischemic optic neuropathy (NAION) compared to healthy gender- and age-matched subjects. Methods: The study subjects were separated into 2 groups: 66 eyes of 33 patients with unilateral NAION (study group) and 33 eyes of 33 healthy individuals (control group). Reichert ocular response analyzer (Reichert Ophthalmic Instruments) was used to assess corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure values. Also, central corneal thickness was measured using Scheimpflug camera combined with a Placido disc corneal topographer (Sirius; Costruzioni Strumenti Oftalmici). Results: Mean CH and median CRF values were significantly lower in the affected eyes (8.8 ± 1.8 mm Hg, 9.4 mm Hg, respectively) and contralateral unaffected eyes (9.1 ± 1.6 mm Hg, 9.8 mm Hg, respectively) of NAION patients than those in the control group (9.9 ± 1.3 mm Hg, 10.4 mm Hg, respectively; all P < 0.017). Mean IOPcc was significantly higher in the affected eyes of NAION patients (19.2 ± 3.5 mm Hg) than in the eyes of control group (17.1 ± 3.6 mm Hg; P = 0.002). Conclusions: CH and CRF are significantly reduced in patients with NAION, possibly indirectly reflecting structural weakness in the lamina cribrosa.

Evaluation of Serum Fibrinogen, Plasminogen, α2-Anti-Plasmin, and Plasminogen Activator Inhibitor Levels (PAI) and Their Correlation with Presence of Retinopathy in Patients with Type 1 DM

Background. Diabetic retinopathy (DR) is the leading cause of blindness in the world. Retinopathy can still progress despite optimal metabolic control. The aim of the study was to determine whether different degrees of DR (proliferative or nonproliferative) were associated with abnormally modulated hemostatic parameters in patients with T1DM. Method. 52 T1DM patients and 40 healthy controls were enrolled in the study. Patients were subdivided into three categories. Group I was defined as those without retinopathy, group II with NPRP, and group III with PRP. We compared these subgroups with each other and the control group (Group IV) according to the serum fibrinogen, plasminogen, alpha2-anti-plasmin (α2-anti-plasmin), and PAI. Results. We detected that PAI-1, serum fibrinogen, and plasminogen levels were similar between the diabetic and control groups (P = 0.209, P = 0.224, and P = 0.244, resp.), whereas α2-anti-plasmin was higher in Groups I, II, and III compared to the control group (P < 0.01, P < 0.05, and P < 0.001, resp.). There was a positive correlation between serum α2-anti-plasmin and HbA1c levels (r = 0,268, P = 0.031). Conclusion. To our knowledge there is scarce data in the literature about α2-anti-plasmin levels in type 1 diabetes. A positive correlation between α2-anti-plasmin with HbA1c suggests that fibrinolytic markers may improve with disease regulation and better glycemic control.

Bilateral anterior optic neuropathy associated with use of terbinafine.

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Corneal biomechanics in steroid induced ocular hypertension

AIM This study aims to investigate the corneal biomechanical properties of steroid sensitive refractive surgery patients and to compare these with those patients that did not have steroid induced ocular hypertension after refractive surgery. MATERIAL AND METHODS This retrospective study in a tertiary care center involved 48 eyes with steroid induced ocular hypertension (Group I) and 61 eyes of age and sex matched refractive patients who used topical steroids for the same duration as group I without developing ocular hypertension (group II). All patients had preoperative ophthalmological examination, pachymetry and postoperative corneal hysteresis (CH) and resistance factor (CRF) measurements by ocular response analyser. The preoperative CH and CRF measurements of the two groups were compared. RESULTS The mean CH was statistically lower in group I (6.89±1.62) as compared to group II (7.80±1.30) (p=0.001). The CRF was higher in group I (7.68±2.26) as compared to group II (7.66±1.72) but the difference was not statistically significant (p=0.96). The preoperative spherical refractive error (r=0.43, p=0.00) and postoperative corneal thickness (r=0.58, p=0.001) were moderately correlated with CH. CONCLUSIONS A statistically significant decrease in CH in subjects with steroid induced ocular hypertension is found. Previous studies have revealed an association of low CH with risk of glaucomatous damage of optic nerve. This may imply risk of optic disc damage in this ocular hypertension group if not recognized and treated properly. However the results should be confirmed with larger sample sizes.

Long-term effects of prostaglandin analogues on the anterior chamber depth of patients with primary open-angle glaucoma

Objective: To evaluate the effect of long-term application of bimatoprost and latanoprost on the anterior chamber depth of primary open-angle glaucoma patients. Methods: The anterior chamber depth (ACD) and axial length (AL) of patients using prostaglandin analogues for open-angle glaucoma (group I) and an age- and gender-adjusted control group (group II) were measured by ultrasonography. Patients using bimatoprost and those using latanoprost were also compared in terms of ACD and AL. Results: The mean ACD of group I (27 eyes of 27 subjects) was significantly lower than that of group II (30 eyes of 30 subjects) (p = .012). Similarly, the ratio of ACD to AL was significantly lower in group I compared with group II (p = .001). The ACDs of patients using bimatoprost or latanoprost and the control group were not significantly different by Kruskal-Wallis test (p = .056), but the differences of these 3 groups in ACD/AL ratios were significant (p = .004). When the Mann Whitney U test was used for pairwise comparison, there was a significant difference between the control group and the patients using latanoprost or bimatoprost in terms of the ACD/AL ratio (p = .008 for each). There was no difference between the patients using latanoprost and those using bimatoprost in terms of the ACD/AL ratio (p = .4). Conclusion: The ACD of patients on prolonged therapy with prostaglandin analogues seems to be lower than than that of the control group. However, prospective long-term studies on large number of subjects are needed to evaluate the effect of each type of prostaglandin on ocular structures.