Retinal Response of Low Myopes during Orthokeratology Treatment

Abstract

The aim of this study was to evaluate the changes in retinal activity during orthokeratology (OK) treatment in 20 myopic eyes. Pattern electroretinography (PERG) and visual evoked potential (VEP) were assessed with the RETI-port/scan21 (Roland Consult, Wiesbaden, Germany). Measurements were taken at baseline (BL) and 1 night (1N), 15 nights (15N), 30 nights (30N), and 60 nights (60N) of OK lens wear. Repeated measures analysis of variance (ANOVA) and the Friedman test were used. Twenty eyes (23.20 ± 3.46 years, 70% female) with visual acuity ≤ 0.00 logMAR in post-treatment showed that despite a slight increase in retinal and cortical response amplitude, observed with both PERG and VEP, respectively, immediately after the initial treatment, these differences found were not statistically significant during the 60 days of OK treatment, despite a statistically significant increase in N95 response with PERG. This shows that retinal and cortical visual-related electrical activity is maintained or slightly increased during OK treatment.

Keywords: myopia control; orthokeratology; pattern electroretinography; visual evoked potentials.

Figure 1

(a) Checkerboard pattern with red fixation point; (b) typical waveform of pattern electroretinography (PERG), horizontal arrows indicate implicit time of N35, P50 and N95 (ms) and vertical arrows indicate amplitude values of P50 and N95; (c) typical waveform of visual evoked potential (VEP), horizontal arrows indicate implicit time of N75 and P100 (ms) and vertical arrow indicates amplitude of P100.

Figure 2

Box plot presentation of the variation of the implicit peak times (N35, P50 and N95) and the variation of the peak amplitude (P50 and N95) of the PERG wave before OK treatment (B-orange) and after OK treatment (Blue: 1N—1 night, 15N—15 nights, 1M—1 month, 2M—2 months). The circles and asterisk refer to outliers found in the measurements corresponding to the number of the eye shown in the figure.