Prevalence and Progression of Pigment Clumping Associated with Idiopathic Macular Telangiectasia Type 2
Year of Publication
Meleth, AD; Toy, B; Krishnadev, N; Murphy, RP; Chew, EY; Wong, WT; Nigam, DL
Annual Meeting, Association for Research in Vision and Ophthalmology (ARVO)
Ft. Lauderdale, FL
clinical (human) or epidemiologic studies; degenerations/dystrophies; macula/fovea; macular disease; macular telangiectasia type 2; natural history
Purpose: To determine incidence and progression of pigment clumping in patients with MacTel2. Methods: Patients with a diagnosis of MacTel2 in at least one eye and at least 12 months of follow-up were identified from two retinal clinics and reviewed retrospectively. Fundus photographs at baseline and subsequent visits were evaluated longitudinally for the presence and location of involvement of pigment clumping. Correlative analyses of pigment clumping with visual acuity, OCT findings, and microperimetry findings were also performed. Results: The study involved 54 eyes in 27 patients with a mean follow-up of 42.5±14.2 months (range 12-79 months). At the initial/baseline visit, 53 eyes (98%) were determined to have clinical signs of MacTel2. Of these, 18 eyes (34%) had evidence of pigment clumping. Mean baseline logMAR visual acuity was significantly lower in eyes with pigment clumping (n = 18) compared to eyes without (n = 35) (0.58±0.27 (approximately 20/76) versus 0.26±0.31 (20/36)); p <0.01, student’s t-test). Longitudinal review revealed that new onset of pigment clumping occurred in 12/35 (34%) eyes, with the majority of new pigment appearing in the temporal perifoveal region. Quantitative analysis revealed that pigment clumping in all eyes increased as a function of time. Neovascular changes were observed in7/53 (13%) eyes with MacTel2; in 3 eyes, neovascular changes preceded the onset of pigment clumping, while in 3 eyes, pigment clumping was present concurrently with neovascular changes and in the final eye, pigment was present prior to neovascular changes. Conclusions: Pigment clumping is a clinical feature commonly found in MacTel2 and may be associated with lower visual acuity in affected eyes. Pigment clumping arises in typical fundus locations and increases in total area during the natural history of the disease. No apparent association was detected between pigment clumping and the development of neovascular changes. Pigment clumping is a prominent feature in the progression of MacTel2 and may constitute a useful outcome measure for clinical study.