Title

PREVALENCE OF FOCAL INNER, MIDDLE AND COMBINED RETINAL THINNING IN DIFFERENT STAGES OF DIABETIC RETINOPATHY USING OPTICAL COHERENCE TOMOGRAPHY AND ITS RELATIONSHIP WITH SYSTEMIC AND OCULAR PARAMETERS

Introduction

To determine the prevalence of focal inner, middle and combined inner and middle retinal thinning (FIRT, FMRT, and FCRT, respectively) in different stages of diabetic retinopathy (DR) using optical coherence tomography (OCT) and to assess the relationship between such findings with ocular or systemic parameters.

Methods

A cross-sectional, masked, comparative and consecutive study consisting of healthy subjects and diabetic patients with different stages of DR. Forty-nine horizontal macular scans of each eye were obtained using Spectral Domain—OCT (SD-OCT) and analyzed for the presence of FIRT, FMRT or FCRT and any relationship with systemic or ocular parameters.

Results

380 eyes of 190 patients were examined. Although some diabetic patients without DR demonstrated focal retinal thinning (FRT), more prevalent and more severe FRT were observed in eyes with advanced DR, in comparison with the eyes of healthy subjects. Analysis revealed statistically significant positive correlation among FIRT, FMRT and FCRT. FRT was associated with coronary artery disease (CAD) and DR stages, positively correlated with diabetic duration, glycated hemoglobin levels and serum creatinine, and negatively correlated with visual acuity, estimated glomerular filtration rate, and choroidal thickness. No relationship was observed with age, gender, race, capillary blood glucose test (BGT), fast BGT, height, weight, diabetic type, systemic arterial hypertension, dyslipidemia, body mass index, axial length of the eye, systolic and diastolic blood pressure or macular central subfield thickness.

Discussion

FRT occurs in all stages of DR and is increasingly prevalent with the severity of DR. Inner, middle and combined FRT is positively correlated. Patients with long diabetes duration, poor glucose control, renal dysfunction, or CAD are more susceptible to development of FRT that can lead to visual dysfunction.

Keywords

Superficial capillary plexus ischemia, deep capillary plexus ischemia, choroidal thickness, diabetic retinopathy, optical coherence tomography, retinal thinning.

Area

CLINICAL CASE

Authors

Rony C Preti, Maria F Abalem, Maria F Abalem, LEANDRO C ZACHARIAS, LEANDRO C ZACHARIAS, MARIO R L MONTEIRO, MARIO R L MONTEIRO, DAVID SARRAF, DAVID SARRAF