The role of fundus autofluorescence in late-onset retinitis pigmentosa (LORP) diagnosis

Abstract

Purpose: To demonstrate the utility and characteristics of fundus autofluorescence in late-onset retinitis pigmentosa.

Methods: Observational case series. Patients diagnosed with late-onset retinitis pigmentosa were identified retrospectively in an institutional setting. Twelve eyes of six patients were identified and medical records were reviewed.

Results: All patients presented with slowly progressive peripheral field loss and initial clinical examination revealed only subtle retinal changes. There was a notable lack of intraretinal pigment migration in all patients. Five out of six patients underwent magnetic resonance imaging of the brain to rule out intracranial processes and all were referred from another ophthalmologist for further evaluation. Fundus autofluorescence was ultimately employed in all patients and revealed more extensive retinal pathology than initially appreciated on clinical examination. Fundus autofluorescence directed the workup toward a retinal etiology in all cases and led to the eventual diagnosis of late-onset retinitis pigmentosa through electroretinogram testing.

Conclusion: Fundus autofluorescence may be a more sensitive marker for retinal pathology than stereo fundus biomicroscopy alone in late-onset retinitis pigmentosa. Early use of fundus autofluorescence imaging in the evaluation of patients with subtle retinal lesions and complaints of peripheral field loss may be an effective strategy for timely and cost-efficient diagnosis.

Keywords: Fundus autofluorescence; late-onset retinitis pigmentosa; magnetic resonance imaging.

FIGURE 1

Case 1. Fundus photographs (a & b) reveal retinal pigment epithelium atrophy along the arcades and peripapillary regions in both eyes without suggestions of intraretinal pigment migration. Fundus autofluorescence (c & d) shows extensive hypofluorescent regions along the arcades and mid-periphery. Regions of scalloped atrophy are noted nasally in both eyes.

FIGURE 2

Case 2. Fundus photographs (a & b) reveal peripapillary atrophy in both eyes and a large chorioretinal scar superonasally and congenital hypertrophy of the retinal pigment epithelium inferonasally in the right eye. No optic nerve pallor, arteriolar attenuation, or intraretinal pigment migration is noted. Fundus autofluorescence (c & d) shows hypofluorescence in the peripapillary regions and along the arcades of both eyes.

FIGURE 3

Case 3. Fundus photographs (a & b) demonstrate mild optic nerve pallor and minimal pigmentary changes in the macula of both eyes. In the peripheral retina (not shown) there was a rare intraretinal pigment migration with lacunar cobblestone degeneration at the periphery. Fundus autofluorescence (c & d) shows hypofluorescence in the peripapillary region extending along the arcades.

FIGURE 4

Case 4. Color photographs (a & b) demonstrate a normal funduscopic examination and a notable absence of the typical clinical signs of retinitis pigmentosa such as waxy optic nerve pallor, attenuated arterioles, and intraretinal pigment migration. Fundus autofluorescence (c & d) reveals a hyperfluorescent ring commonly associated with retinitis pigmentosa.

FIGURE 5

Case 5. Fundus photographs (a & b) reveal rare intraretinal pigment inferiorly and peripheral drusen in both eyes. Fundus autofluorescence (c & d) shows high-density macular fluorescence rings and displacement of macular pigment in the foveal region consistent with chronic cystoid macular edema.

FIGURE 6

Case 6. Fundus photographs (a & b) reveals rare intraretinal pigment and bull’s eye maculopathy. Hypofluorescence of the midperiphery is seen on fundus autofluorescence imaging (c & d), consistent with retinitis pigmentosa.