Comparative Evaluation of Macular Thickness in Sickle Cell and Non-Sickle Cell Disease Patients at the University College Hospital (Uch) Ibadan, Oyo State, Nigeria

Abstract

BACKGROUND: The prevalence of sickle cell disease (SCD) is high in Nigeria, and macular thinning is one of its ocular complications. However, there are currently no local data in the literature on macular thickness in Nigerians with SCD. This study provides comparative baseline data on the macular thickness profile of an indigenous Nigerian population to address this gap. AIMS: To determine the macular thickness of participants with SCD and compare with their age- and sex-matched participants without SCD at the University College Hospital (UCH), Ibadan. MATERIALS AND METHODS: This was a hospital-based comparative study conducted at the University College Hospital, Ibadan. Patients with SCD aged 18 years and above were age- and sex-matched with non-SCD controls (haemoglobin AA genotype). All participants underwent a full ophthalmic examination, refraction and A-scan biometry and macular thickness was measured with an Optovue iScan spectral-domain optical coherence tomography machine. Data from the left eye of each participant were analysed with IBM Statistical Package for Social Sciences (SPSS) version 25.0. RESULTS: Seventy participants were recruited into the study and 30 (42.9%) were males. The mean age of all the subjects in the study was 35.9 ± 11.0 years. Group 1 (SCD) comprised 19 (27.1%) Hb SS and 16 (22.9%) Hb SC, whereas Group 2 (non-SCD) were 35 (50%) Hb AA subjects. The SCD group had lower mean macular thickness (MMT) of 271.1 ± 20.2 µm compared to non-SCD group with MMT of 278.5 ± 13.5 µm, but this was not statistically significant (P = 0.076). Macular thickness was generally lower in SCD group in all the ETDRS map regions of the macular compared to the non-SCD group with values ranging from 3.0 to 11.5 µm, but statistically significant difference was observed only in the inner inferior macular (P = 0.026) and inner temporal macular (P = 0.046) regions. There was no statistically significant difference in distant visual acuity between non-SCD and SCD participants (P = 0.605). CONCLUSION: This study observed focal macular thinning in SCD compared to non-SCD. However, focal macular thinning was not associated with poorer distant visual acuity in patients with SCD.