Peripapillary retinal nerve fiber layer thickness in sickle-cell hemoglobinopathies using spectral-domain optical coherence tomography

Abstract

Purpose: To determine whether patients with a sickle-cell hemoglobinopathy without glaucoma have peripapillary retinal nerve fiber layer (RNFL) thinning by spectral-domain optical coherence tomography.

Design: Prospective study.

Methods: All patients with a sickle cell hemoglobinopathy (sickle-cell disease, sickle-cell hemoglobin C disease, and sickle-cell thalassemia) and age-similar, race-matched controls underwent a comprehensive eye examination and spectral-domain optical coherence tomography of the macula and optic nerve head using the Heidelberg Spectralis (Heidelberg Engineering, Inc, Carlsbad, California, USA). Participants with prior retinal treatments (laser or surgery), diabetes mellitus, glaucoma, or other ocular diseases were excluded. The sickle-cell disease patients were grouped into those with focal macular thinning and those without. Those with macular thinning were grouped further into mild, moderate, and severe thinning groups based on temporal macular thickness. Analysis of variance testing and post hoc analysis with the Tukey test and Pearson correlation were performed to assess for peripapillary RNFL thickness differences among different groups.

Results: One hundred fifty-one eyes of 88 sickle-cell patients and 55 eyes of 30 age-similar and race-matched (black) controls were included. Sickle-cell patient eyes with macular thinning (n = 81) had thinner mean peripapillary RNFL thicknesses in the nasal sector (P = .01) compared with non-sickle-cell control eyes and in the superotemporal sector (P = .01) compared with sickle-cell patient eyes without macular thinning (n = 70). In the severe macular thinning subgroup (n = 55), the mean peripapillary RNFL thickness was significantly thinner than that of controls (P < .05) in 6 of 7 sectors. There is a positive linear relationship between temporal macular thickness and global peripapillary RNFL thickness with a Pearson correlation coefficient of 0.60 (P < .0001).

Conclusions: Nonglaucomatous, black sickle-cell patients with focal macular thinning on spectral-domain optical coherence tomography have significantly thinner peripapillary RNFL than those without macular thinning or controls. The degree of thinning correlates with severity of temporal macular thinning. These patients may require different peripapillary RNFL thickness thresholds for future glaucoma evaluations.