Abstract
Purpose :
To assess reading test performance and its longitudinal change in patients with Type 2 Macular Telangiectasia (MacTel).
Methods :
Eighty-three (83) patients enrolled in the MacTel Natural History Observation Study at Moorfields Eye Hospital were analysed. Patient underwent ETDRS best corrected visual acuity, reading acuity and reading speed test with MNRead with each eye and IReST.
Monocular data are reported for the right eye for simplicity.
Out of the 83 patients, 38 patients (45.8%) had one single assessment as enrolled in the study as part of the Registry and 45 patients (54.2%) had repeated tests at their follow ups as per study protocol.
Results :
Mean visual acuity at baseline was 0.357 LogMAR with the right eye. Mean Reading Acuity was 0.371 LogMar (range -0.300 - 1.010) mean Critical Print Size was 0.822 LogMAR (0.200 - 1.300), mean Maximum Reading Rate was 130.775 wpm (words per minute, 37 - 220). Mean Maximum Reading Rate with IReST test was 101wpm (0 - 235). In general, reading acuity was strongly associated with single letter acuity (R2=0.61) but neither were strongly associated with maximum reading speed (R2<0.3). Four eyes (2.4%) showed a reduced measured reading speed on MNRead (<160wpm) despite having a visual acuity of 0.0 LogMAR or better.
Mean follow up for the 45 patients with repeated tests was 28.1 months (6 - 49). With the right eye, the mean change in Reading Acuity was 0.039 LogMar (SD 0.322), the mean change in Critical Size Print was 0.100 LogMar (SD 0.215) and the mean change in Maximum Reading Rate was 5.459 wpm (SD 29.490).
Twenty-two (22) patients (26.5%) underwent serial MNRead tests with both eyes open. In this subset of patients mean Reading Acuity at baseline and its mean change were 0.210 LogMAR and 0.003 LogMar (SD 0.006) respectively, mean Critical Size Print were 0.700 LogMAR and 0.003 LogMar (SD 0.0091), mean Maximum Reading Rate were 134.636 wpm and -1.813 wpm (SD 11.184).
Mean change in Mean Maximum Reading Rate with IReSTtest was -3.786 wpm (SD 34.204).
Conclusions :
Patients with MacTel show a reduced reading speed performance and this can be documented also in eyes with good vision. The reduced speed performance shows relative stability over time, with some variability between individuals. Further analysis to evaluate the level of drop in reading speed with regards to the location of the scotoma on microperimetry test would be of value.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.