Structural and functional changes over time in MacTel patients

PURPOSE: To investigate functional and morphologic alterations over a 1-year review analysis in patients with type 2 idiopathic juxtafoveal retinal telangiectasia (MacTel).

METHODS: Nine eyes of 9 patients with MacTel underwent repeated scotopic and photopic fine matrix mapping (FMM), 10-2 photopic microperimetry, and imaging studies.

RESULTS: Early Treatment Diabetic Retinopathy Study visual acuity assessment showed a median difference between examinations of 1.0 letter (range, -3 to 4 letters). The difference of sensitivity values of all test points was 4.5 dB (range, 0.4 -5.5 dB) for microperimetry 1, 0.4 dB (range, -0.8 to 1.7 dB) for photopic, and -1.7 dB (range, -6.1 to 1.0 dB) for scotopic fine matrix mapping, respectively. The difference in test points of more than a 10-dB loss compared with age-matched controls was higher for scotopic than for photopic testing (P= 0.03, Wilcoxon signed ranks test). Small progression of scotoma correlated with a slight increase in retinal blood vessel dilatation and hyperfluorescence and subtle enlargement of pigmented plaques.

CONCLUSION: Changes in central visual acuity and microperimetry testing after 1 year most likely do not extend beyond test-retest variability. The deterioration of scotopic sensitivity confirms our previous results of more severe rod compared with cone dysfunction in MacTel. Changes in fine detail visual function over a 1-year period may be useful parameters for interventional trials.