Near reading speed changes after the panretinal photocoagulation in diabetic retinopathy patients; Using the reading speed measure application.

Abstract

Purpose : To investigate near reading speed change after the panretinal photocoagulation in diabetic retinopathy patients using the reading speed application.

Methods : Prospective study was conducted to the patients undergoing PASCAL (pattern scanning laser) panretinal panretinal photocoagulation(PRP) due to diabetic retinopathy. Near reading speed were measured at before PRP and at 1 week, 1 month, and 4 months after PRP by using reading speeding application. A third-generation retina display iPad was used to present the chart, and the sentences were presented randomly for each size of letter. The subjects repeated the test silently (reading only) and out loud (reading and speaking) to prevent them from skipping reading words. When the participant is finished examination, the app automatically calculates the near reading speed in words per minute (WPM) and letters per minute (LPM). We also analyzed changes in near and far visual acuity, pupil size, central retinal thickness and choroidal thickness before and after PRP.

Results : Forty-four diabetic patients and forty age-matched control were enrolled in the study. The mean age of diabetic patients and age matched control were 53.81 ± 10.75, 51.50 ± 6.55 years, respectively. The mean duration of diabetes mellitus was 10.14 ± 7.51 years, and 17 patients with non-proliferative diabetic retinopathy and 24 patients with proliferative diabetic retinopathy. The near reading speed (WPM and LPM) of diabetic retinopathy group was significantly slower than age-matched control group. The near reading speed (WPM and LPM) tended to decrease at 1 week after PRP, however this decrease was recovered to its original level at 1 and 4 months after PRP. The pupil size (mesopic and photopic condition) was constantly increased. There were no significant changes in near and far visual acuity before and after PRP. There was no significant change in central retinal thickness before and after PRP. Choroidal thickness increased at 1 week after PRP and decreased gradually at 1 month and 4 months.

Conclusions : The near reading speed was decreased at 1 week after PRP, and it recovered with time. This is thought to be caused by temporary impairment of the parasympathetic nerve innervation to the ciliary body after the PRP. Therefore, we could know that PRP with PASCAL laser did not cause permanent impairment of near reading speed.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.