Altinkurt, Emre; Avci, Ozkan; Muftuoglu, Orkun; Ugurlu, Adem; Cebeci, Zafer; Ozbilen, Kemal Turgay

Purpose. Diagnose keratoconus by establishing an effective logistic regression model from the data obtained with a Scheimpflug-Placido cornea topographer. Methods. Topographical parameters of 125 eyes of 70 patients diagnosed with keratoconus by clinical or topographical findings were compared with 120 eyes of 63 patients who were defined as keratorefractive surgery candidates. The receiver operating character (ROC) curve analysis was performed to determine the diagnostic ability of the topographic parameters. The data set of parameters with an AUROC (area under the ROC curve) value greater than 0.9 was analyzed with logistic regression analysis (LRA) to determine the most predictive model that could diagnose keratoconus. A logit formula of the model was built, and the logit values of every eye in the study were calculated according to this formula. Then, an ROC analysis of the logit values was done. Results. Baiocchi Calossi Versaci front index (BCVf) had the highest AUROC value (0.976) in the study. The LRA model, which had the highest prediction ability, had 97.5% accuracy, 96.8% sensitivity, and 99.2% specificity. The most significant parameters were found to be BCVf (p=0.001), BCVb (Baiocchi Calossi Versaci back) (p=0.002), posterior rf (apical radius of the flattest meridian of the aspherotoric surface in 4.5 mm diameter of the cornea) (p=0.005), central corneal thickness (p=0.072), and minimum corneal thickness (p=0.494). Conclusions. The LRA model can distinguish keratoconus corneas from normal ones with high accuracy without the need for complex computer algorithms.

Taşli, Nurdan Gamze; Ersoy, Alevtina

Aim. We aimed to determine the alterations in macular and optic nerve vasculature in patients with migraine without aura using optical coherence tomography-angiography (OCTA). We also aimed to determine whether there were clinical differences and alterations in ocular structures in migraine cases with white matter hyperintensities (WMH) using magnetic resonance imaging (MRI). Materials and Methods. The study group comprised patients with migraine without aura and age- A nd sex-matched healthy controls. Detailed histories of the patients with migraine were recorded including the disease duration, number of attacks in the last month, and attack durations. Visual evoked potentials (VEP) were recorded in all migraine patients. The migraine disability assessment (MIDAS) questionnaire was administered to all patients. The patients were divided into two groups as migraine with WMHs and migraine without WMHs. All subjects underwent a complete neurological and ophthalmological examination. Only the right eyes of the patients were included in the study. Retinal imaging was performed using OCT and OCTA. Results. A total of 66 migraine patients (29 with WMH and 37 without WMH) and 43 healthy controls were included in this study. Among the migraine patients, disease duration, attack frequency in the last month, attack durations, and the visual analogue scale (VAS), MIDAS, and VEP scores were all similar between those with and without WMHs. There was no significant difference between the groups regarding the ganglion cell complex, foveal, and retinal nerve fiber layer thicknesses. The superficial or deep vascular perfusion densities of the optic disc were also similar between the groups. The foveal avascular zone (FAZ) was significantly larger (P=0.034), and both superficial and deep macular vascular densities were significantly lower in the migraine groups compared with the healthy controls (P=0.001). There was no significant difference concerning the FAZ size or vascular densities between the migraine groups with and without WMHs. In the correlation analysis performed between the migraine patients, the FAZ size was correlated with age and VAS and MIDAS scores while both superficial and deep macular vascular densities were negatively correlated with age and VAS and MIDAS scores. Conclusion. We suggest that for not only migraine with aura but also migraine without aura, neurovascular structures play an important role in pathogenesis, and novel studies are warranted to elucidate the alterations in these and determine the significance of WMHs in these patient groups.

Ucak, Turgay; Unver, Ethem

Purpose. To analyze the effects of obstructive sleep apnea syndrome (OSAS) on ocular parameters and determine the alterations in macular vasculature by optical coherence tomography-angiography (OCT-A) in patients with different stages of OSAS. Methods. All the participants underwent a full ophthalmological examination. Using the macular OCT-A scans, the retinal peripapillary capillary plexus (RPCP), foveal avascular zone (FAZ), and superficial and deep vessel densities were recorded. Results. A total of 77 patients (154 eyes) with OSAS and 27 control cases (54 eyes) were included in this prospective study. Of the OSAS patients, 27 had mild, 24 had moderate, and 26 had severe disease. The intraocular pressure (IOP) values were significantly higher in the severe OSAS group than the control cases (p=0.001). The average retinal nerve fiber layer (RNFL) thickness and the RNFL thickness of the temporal and inferior quadrants were significantly lower in the severe OSAS group compared with the control cases (p<0.05). There was a significant decrease in the mean RPCP values with a significant increase in the FAZ values of OSAS patients compared with the control group (p=0.001). Both the superficial and deep vascular densities were significantly decreased in OSAS patients, being the lowest in the severe OSAS group. Conclusions. Decreased vascular structures and increased FAZ may also be associated with the disease severity in OSAS and may be the main pathophysiological mechanisms in ocular alterations, which should be investigated in further studies.

Ugurlu, Adem; Altinkurt, Emre

Purpose. To evaluate ocular findings in children with Down syndrome and to compare with the healthy children group. Methods. The study patients were divided into two groups as the diagnosed Down syndrome group and the control group. The study was designed as a prospective and single-center study in Istanbul University Faculty of Medicine Department of Ophthalmology. The study included 93 patients in the age range from 7 to 18 years, who applied to the ophthalmology department of our clinic in the period from July 2017 to June 2018. The study included the patients allocated into the control group and the Down syndrome patients allocated into the patient group, containing 49 and 44 participants, respectively. All patients underwent complete ophthalmologic examination with biomicroscopy. Autorefractometer measurements were performed in all patients, and the best corrected visual acuity (BCVA) was determined with the use of the Snellen chart. All patients underwent spectral domain optical coherence tomography (SD-OCT) measurements for central foveal retinal (CRT), subfoveal choroidal (CCT), and peripapillary retinal nerve fiber layer (pRNFL) thicknesses. Results. The average CRT was 241.2 ± 25.7 microns in Down syndrome group and 219.4 ± 21.1 microns in the control group. There was a statistically significant difference between the groups in regards to CRT (p<0.001). The average pRNFL values were 123.1 ± 15.4 microns in the Down syndrome group and 102.2 ± 8.7 microns in the control group (p<0.001). Conclusions. In the subjects with Down syndrome, the incidence of lens opacities, strabismus, and amblyopia was higher than the control group. CRT and pRNFL were thicker in the Down syndrome group than in control group. This may represent retinal developmental changes in the patients with Down syndrome.

Oruc, Yavuz; Keser, Sinem; Yusufoglu, Elif; Celik, Fatih; Sahin, Ibrahim; Yardim, Meltem; Aydin, Suleyman

Purpose. Pseudoexfoliation syndrome (PEX) is an eye disease that develops under the influence of regional population differences, genetic factors, age, and environmental factors and is characterized by visualization of a gray-white fibrogranular substance in the lens anterior capsule and/or pupil margin during anterior segment examination. The underlying biochemical mechanisms of the disease have not yet been fully elucidated. Therefore, this study was designed to show the changes in aqueous humor and blood serum levels of matrix metalloproteinases (decorin and tenascin C), total antioxidants (TAS), and total oxidants (TOS) in both cataract patients who have unilateral PEX material and cataract patients who do not have unilateral PEX material. Methods. Biological samples were simultaneously collected from 22 cataract patients who had unilateral pseudoexfoliation (PEX patients) and 22 cataract patients who did not have unilateral pseudoexfoliation (control patients). From the collected biological samples, decorin (DEC) and tenascin C (TN-C) were measured with the enzyme-linked immunosorbent assay (ELISA) method, and TAS and TOS were measured with an autoanalyzer. Results. When decorin, tenascin C, and TOS values of PEX patients were compared with those of control patients, there was a statistically significant increase in all three parameters. Conversely, TAS values showed a statistically significant decrease in PEX patients compared to controls. DEC, TN-C, TAS values, and TOS values were significantly higher in aqueous fluid than in blood in both the PEX patient and control groups. Conclusions. We suggest that parameters such as DEC, TN-C, TAS, and TOS play a role in the etiopathology of pseudoexfoliation syndrome. Thus, bringing these increased levels of extracellular proteins and TOS and decreased levels of TAS back to within physiological limits can mediate the reorganization of the blood-aqueous fluid barrier and slow the progression of pseudoexfoliation syndrome.