Purchase this article with an account.
S. Baumueller, P. Charbel Issa, F. G. Holz, H. P. N. Scholl; Disease Progression in Patients With Macular Telangiectasia Type 2 Monitored by Microperimetry. Invest. Ophthalmol. Vis. Sci. 2009;50(13):755.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Macular telangiectasia type 2 (MacTel type 2) is a rare bilateral macular disease characterised by incompetent macular capillaries and progressive neurosensory macular atrophy. Besides slow deterioration of visual acuity, parafoveal scotomas have been described as characteristic functional alterations. We analyzed visual acuity loss and progression of parafoveal sensitivity loss in patients with nonproliferative MacTel type 2.
In a prospective observational longitudinal study, 15 eyes of 8 patients with MacTel type 2 underwent serial standardized microperimetry (MP1, Nidek) and best-corrected visual acuity (BCVA) testing. Retinal sensitivity was measured at 45 locations on a 8 deg (horizontal) by 4 deg (vertical) matrix of 1 deg spacing centered at the macular area. At follow up, fundus-related microperimetry allowed to re-evaluate the same testing points and to record changes in retinal sensitivity over time. In order to avoid learning effects within the analyzed period, several exams were performed before the baseline test until overall stable results were obtained. Microperimetry was always obtained by the same examiner (PCI).
Mean follow up time was 13 months. Change in sensitivity was ≥10db in 4 eyes (group 1), ≥6db in 4 eyes (group 2) and between -4db and +4db in the remaining7 eyes (group 3). Two eyes within group 1 lost 7 ETDRS letters, while all other eyes remained stable (+/- 5 letters). All except one eye in groups 1 and 2, but only one eye in group 3 presented with a scotoma at baseline.
Paracentral loss of retinal sensitivity appears to precede loss in distance visual acuity in MacTel type 2. A subset of eyes without scotoma at baseline remained stable while all eyes with a scotoma at baseline showed further deterioration of parafoveale sensitivity. This suggests that a certain degree of disease related retinal damage is necessary before progressing scotomas develop. Microperimetry will be helpful in studying the natural history and to monitor treatment effects in MacTel type 2.
This PDF is available to Subscribers Only