The prevalence of macular telangiectasia type 2 in the Beaver Dam eye study

Abstract

Purpose: To examine the prevalence of macular telangiectasia type 2 and lesions characterizing it.

Design: Population-based cohort study.

Methods: setting: City and township of Beaver Dam, 1988-1990. study population: A total of 4790 people 43-86 years of age. observation procedure(s): Grading from stereoscopic fundus photographs to measure macular telangiectasia type 2. main outcome measure: Prevalent macular telangiectasia type 2.

Results: Macular telangiectasia type 2 was present at baseline in 0.1% of the population (95% confidence interval [CI] 0.09, 0.1). The frequencies of loss of retinal transparency, crystals in the inner retinal layers, blunted retinal vessels, localized intraretinal pigment migration in the juxtafoveolar region, and presence of yellow deposits and lamellar holes in the foveal area in those without macular telangiectasia type 2 varied from 0.06% for retinal telangiectatic vessels to 1.2% for lamellar holes. Smoking was associated with pigment clumping (odds ratio [OR] per pack year 1.02; 95% CI 1.00, 1.03; P = .02), retinal pigment epithelial (RPE) depigmentation (OR 1.02 per pack year; 95%CI 1.00, 1.04; P = .02), loss of transparency (OR 1.02 per pack year; 95% CI 1.00, 1.03; P = .008), and the presence of a yellow spot in the fovea (OR 2.24 current vs past or never smoker; 95% CI 1.29, 3.89; P = .004), but not with presence of macular telangiectasia type 2 (OR 2.72; 95% CI 0.45, 16.28; P = .27).

Conclusions: The prevalence of macular telangiectasia type 2 (0.1%) is higher than previously thought. These data are useful in estimating the burden of this condition in the population. The role of smoking in the development of macular telangiectasia type 2 requires further study.

Figure 1

Lesions characterizing macular telangiectasia type 2 from patients not participating in the Beaver Dam Eye Study. A. Loss of transparency; B. Retinal crystals (black arrow) and pigment clumping (white arrow); C. Lamellar hole (black arrow), yellowish spot, and retinal vessel blunting (white arrow); D. Telangiectatic retinal vessels (black arrow), pigment clumping, and RPE depigmentation.

Figure 2

Development of macular telangiectasia type 2 in right eye of participant categorized as having macular telangiectasia type 2 in left eye. L. Baseline - left eye with blunted retinal vessels, retinal pigment clumping, retinal crystalline deposits, RPE depigmentation, and retinal telangiectatic vessels (black arrow); 5 year follow-up visit - a temporal lesion of pigment clumping and depigmentation has appeared with increasing size at the 10 year and 15 year follow-up visits (white arrow); R. Baseline and 5 year follow-up visit - right eye with beginnings of blunted retinal vessels and retinal crystals; 10 year follow-up visit - now labeled as having macular telangiectasia type 2 with retinal crystals, pigment clumping, and RPE depigmentation temporal to the macula (black arrow); 15 year follow-up visit - a temporal lesion of retinal pigment clumping and depigmentation (white arrow) similar to the left eye has developed.

Figure 3

Four other participants with macular telangiectasia type 2 at the Beaver Dam Eye Study baseline examination in 1988–90. A. Right eye with pigment clumping (black arrow), retinal crystals, retinal vessel blunting, and RPE depigmentation; B. Left eye of same person with lamellar hole (green arrow), pigment clumping, RPE depigmentation, and retinal crystals; C. Left eye with RPE depigmentation (black/white arrow), pigment clumping, retinal crystals, and a loss of retinal transparency; other eye with no signs of macular telangiectasia type 2 is not shown; D. Left eye with retinal crystals (yellow arrow), pigment clumping, and RPE depigmentation; other eye with no signs of macular telangiectasia type 2 is not shown; E. Right eye with loss of retinal transparency (gray arrows), retinal vessel blunting, retinal crystals, pigment clumping and RPE depigmentation; F. Left eye of same person with a lamellar hole, loss of retinal transparency, vessel blunting, retinal crystals, pigment clumping and RPE depigmentation.