Optic Nerve Head and Retinal Nerve Fiber Layer Differences Between Caribbean Black and African American Patients as Measured by Spectral Domain OCT

Abstract

Findings of this study suggest that optic nerve and RNFL morphology is markedly similar between Caribbean blacks and African Americans once adjusted for optic nerve size but cannot be considered equivalent in all measures, particularly in the superior nerve fiber layer.

Optic disc morphometry using spectral domain optical coherence tomography in a Nigerian population

“…The authors however acknowledge that failure to identify any difference might be a result of the small sample size. 13 A study of Pakistani eyes performed with a Topcon Maestro SD-OCT (same equipment as our study) reported a mean disc area of 2.24 ± 0.44 mm 2 was lower than our findings while an Indian study which used a similar brand of OCT machine reported a mean DA of 2.47 ± 0.37 mm 2 . 24 Based on our literature search, very few studies have evaluated the optic disc parameters using the Topcon 3D OCT-1 Maestro brand for comparison.…”

“…Rao et al 13 which conducted a study comparing optic disc parameters between Caribbean blacks and African Americans but did not find any difference in the DA between the two study groups. The authors however acknowledge that failure to identify any difference might be a result of the small sample size.…”

“…Race measures some combination of genetic, socioeconomic, and cultural factors in addition to phenotypic characteristics and geographic ancestry. 13,14 Studies conducted in the United States of America, using various imaging technologies, have consistently reported that people of black African descent have the largest optic disc size. 9,10,15,16 These studies would have recruited blacks who have evolved into an heterogeneous people with considerable diversity from different continents from countries mainly in sub-Saharan Africa, the Caribbean, and South America.…”

“…9,10,15,16 These studies would have recruited blacks who have evolved into an heterogeneous people with considerable diversity from different continents from countries mainly in sub-Saharan Africa, the Caribbean, and South America. 14 While Rao et al 13 reported that Caribbean blacks and African Americans have similar optic nerve dimensions, studies assessing optic disc dimensions in indigenous black Africans are quite scarce. Failure to identify possible intra-racial variations of optic disc size might undermine the diagnostic ability during the subjective assessment of the optic disc for glaucoma evaluation and other optic nerve-related disorders.…”

A Common Glaucoma-risk Variant of SIX6 Alters Retinal Nerve Fiber Layer and Optic Disc Measures in a European Population: The EPIC-Norfolk Eye Study

“…Some investigators have reported significantly larger optic nerve parameters, including VCDR, optic disc area, and optic cup volume in African Americans or those of African ancestry 27,28. However, other investigators found that the differences in VCDR were lost after adjustment for disc area 29,30. In this study, it is interesting to note that allele-related associations with optic nerve parameters were strengthened after correction for disc area.…”