Material and method
This study was conducted in the Department of Eye Diseases and Skin and Venereal Diseases of Harran University in 2019-2020. Study protocol was approved by the Ethics Committee of Harran University (Document Number: E.35564) and informed consent was received from the participants. The right eyes of sixty generalized vitiligo patients and the right eyes of 60 healthy individuals paired with this patient group in terms of age and gender were included in the study as a control group.
A comprehensive medical history including the drugs used for each patient was taken and general dermatological physical examinations were performed by the same dermatologist. Both groups also underwent a full ophthalmological examination, which included the best corrected visual acuity, intraocular pressure measurement with the Goldmann Applanation Tonometer, refraction, biomicroscopy of the anterior and posterior segment of the eye. Axial length was measured using ultrasonic biometrics Pac-Scan 300p (Sonomed Escalon, NY) and visual field examination was performed using Humphrey perimetry (Carl Zeiss Meditec, Dublin, CA) with 30-2 program.
People under the age of 18, people with cataract or glaucoma, people with a BCVA of 20/40, people with a history of ocular surgery, people with optic nerve or retina disorders, people with systemic diseases that can affect the eye such as diabetes mellitus and hypertension were not included in the study and all patients between the ages of 18 - 40 with generalized vitiligo diagnosis were included in the study.
Choroidal thickness measurements were performed by the same experienced technician in increased depth imaging mode with the Heidelberg spectral domain optical coherence tomography device (SD-OCT, Heidelberg Engineering, Germany). The choroidal thickness was measured manually by marking the distance between the outer border of the retinal pigment epithelium and the choroid-sclera compound. In addition to the thickness of the subfoveal choroid, seven measuring points were determined, including 3 nasal and 3 temporal with 500 µm intervals in the temporal and nasal directions. N1, N2 and N3 abbreviations were given to the points identified in the nasal respectively, from the central to the periphery; and T1, T2 and T3 abbreviations were given to the points identified in the temporal respectively, from the central to the periphery (figure 1). Peripapillary RNFL thickness parameters were calculated automatically with fast RNFL mode. The software calculated average thickness values (µm) for each of the six sectors centred on the optical disk (temporal, temporal superior, temporal inferior, nasal, nasal inferior, and nasal superior) (figure 2). Sections below signal strength index 6/10 were not evaluated. Measurements were made between 09.00-12.00 in the morning to prevent diurnal changes.