BACKGROUND: Gestational diabetes mellitus (GDM) is a risk factor for the development of type II diabetes and it causes maternal and child morbidity. Screening for diabetic retinopathy (DR) is important because patients who develop DR have no symptoms until macular edema and/or proliferative diabetic retinopathy (PDR) are already present. The aim of this study was to determine the early retinal findings of GDM.

MATERIAL AND METHODS: This study was conducted in a tertiary research center. We conducted a prospective cross-sectional study with 3 groups: Group 1 consisted of 36 pregnant women with GDM, Group 2 consisted of 24 healthy pregnant women, and Group 3 consisted of 38 healthy non-pregnant women of reproductive age. Spectralis optical coherence tomography (OCT) was used for the assessment. Macular, choroid, and retinal nerve fiber layer (RNFL) thicknesses were evaluated in patients with GDM and comparisons were made among pregnant women with GDM, healthy pregnant women, and healthy non-pregnant women for these parameters.

RESULTS: The nasal part of the RNFL was significantly thinner in the GDM group than in the healthy pregnant group. None of the patients had retinopathy or macular edema at the time of examination.

CONCLUSIONS: Decreased nasal part of RNFL thickness may be the first retinal change in patients with GDM. Our study suggests that OCT should be performed for the patients with GDM for detection of early retinal changes associated with GDM.

Keywords: Case-Control Studies, Choroid - pathology, Cross-Sectional Studies, Diabetes, Gestational - pathology, Diabetic Retinopathy - pathology, Macular Edema - pathology, Nerve Fibers - pathology, Optic Disk - pathology, Pregnancy, Prospective Studies, Retinal Degeneration - pathology, Tomography, Optical Coherence - methods, Visual Acuity