The optic nerve and retinal vasculature in albinism: Normal or abnormal?

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IntroductionAlbinism, an inherited disorder resulting in reduced ocular melanin, is usually associated with reduced best-corrected visual acuity (BCVA), nystagmus, foveal hypoplasia and iris transillumination. The purpose of this study is to describe the optic nerve (ON) anatomy and peripapillary retinal vasculature in albinism and to examine the relationship to BCVA.MethodsThis IRB-approved study is a retrospective review of 34 patients with albinism and 51 controls seen at the University of Minnesota. The ON and peripapillary vasculature were analyzed by fundus photos using Ophthavision.ResultsOur data indicate that the optic disc diameter (DD) and ON area are statistically smaller in albinism than controls (p <0.001; P = 0.0008). Using DD to disc-macula ratio, with ‘macula’ determined as center of foveal avascular zone, more patients with albinism qualified as optic nerve hypoplasia. Significantly more patients with albinism had a double ring sign, situs inversus and a nasally-directed artery (p at least <0.0148). There was no significant difference between groups for ON color, vessel branching pattern, cilioretinal artery, tortuosity or vessels crossing the ON margin. No correlation of BCVA to DD or ON area was found.DiscussionIn this study, patients with albinism had smaller DD and ON area than controls, confirming the clinical impression of Spedick and Beauchamp (1986). The vasculature was heterogeneous within the albinism group. Reduced BCVA is not explained by the smaller DD and ON area.ConclusionsThe ON in albinism is smaller than controls. Further studies are required to elucidate the cause of the decreased BCVA in albinism. IntroductionAlbinism, an inherited disorder resulting in reduced ocular melanin, is usually associated with reduced best-corrected visual acuity (BCVA), nystagmus, foveal hypoplasia and iris transillumination. The purpose of this study is to describe the optic nerve (ON) anatomy and peripapillary retinal vasculature in albinism and to examine the relationship to BCVA. Albinism, an inherited disorder resulting in reduced ocular melanin, is usually associated with reduced best-corrected visual acuity (BCVA), nystagmus, foveal hypoplasia and iris transillumination. The purpose of this study is to describe the optic nerve (ON) anatomy and peripapillary retinal vasculature in albinism and to examine the relationship to BCVA. MethodsThis IRB-approved study is a retrospective review of 34 patients with albinism and 51 controls seen at the University of Minnesota. The ON and peripapillary vasculature were analyzed by fundus photos using Ophthavision. This IRB-approved study is a retrospective review of 34 patients with albinism and 51 controls seen at the University of Minnesota. The ON and peripapillary vasculature were analyzed by fundus photos using Ophthavision. ResultsOur data indicate that the optic disc diameter (DD) and ON area are statistically smaller in albinism than controls (p <0.001; P = 0.0008). Using DD to disc-macula ratio, with ‘macula’ determined as center of foveal avascular zone, more patients with albinism qualified as optic nerve hypoplasia. Significantly more patients with albinism had a double ring sign, situs inversus and a nasally-directed artery (p at least <0.0148). There was no significant difference between groups for ON color, vessel branching pattern, cilioretinal artery, tortuosity or vessels crossing the ON margin. No correlation of BCVA to DD or ON area was found. Our data indicate that the optic disc diameter (DD) and ON area are statistically smaller in albinism than controls (p <0.001; P = 0.0008). Using DD to disc-macula ratio, with ‘macula’ determined as center of foveal avascular zone, more patients with albinism qualified as optic nerve hypoplasia. Significantly more patients with albinism had a double ring sign, situs inversus and a nasally-directed artery (p at least <0.0148). There was no significant difference between groups for ON color, vessel branching pattern, cilioretinal artery, tortuosity or vessels crossing the ON margin. No correlation of BCVA to DD or ON area was found. DiscussionIn this study, patients with albinism had smaller DD and ON area than controls, confirming the clinical impression of Spedick and Beauchamp (1986). The vasculature was heterogeneous within the albinism group. Reduced BCVA is not explained by the smaller DD and ON area. In this study, patients with albinism had smaller DD and ON area than controls, confirming the clinical impression of Spedick and Beauchamp (1986). The vasculature was heterogeneous within the albinism group. Reduced BCVA is not explained by the smaller DD and ON area. ConclusionsThe ON in albinism is smaller than controls. Further studies are required to elucidate the cause of the decreased BCVA in albinism. The ON in albinism is smaller than controls. Further studies are required to elucidate the cause of the decreased BCVA in albinism.