Abstract
Purpose:
It has been previously shown that diabetic macular edema (DME) patients with relatively good vision can have slow reading speed. In this study, we evaluated the structural-functional correlation in a larger cohort of patients.
Methods:
The study was performed on patients with clinically significant DME. The best corrected visual acuity (BCVA) was recorded with letter counting on a modified ETDRS chart, the maximal reading speed (MRS) was recorded with MNREAD, the retinal sensitivity (MP5) was measured with Optos OTI (only the central five points were included in the analysis) and the central sub-field thickness (CST) was measured by Heidelberg Spectralis Spectral Domain Optical Coherent Topography (SD-OCT). The statistical analysis was carried out by SPSS.
Results:
There were 76 eyes included in the study. The mean patient age was 58.2 years, the mean BCVA was 76.5 letters, the mean MRS was 156.8 words per minute, the mean MP5 was 9.81 dB per point, and the mean CSF was 321.1 microns. It was found that faster MRS is correlated with younger age (p=0.001), better BCVA (p<0.0001), and better retinal sensitivity (p<0.0001), but not with CST (p=0.66). In fact, CST is not correlated with age (p=0.812), BCVA (p=0.113) or MP5 (p=0.485). After correction for age and BCVA, MRS is still correlated with MP5 (p=0.015).
Conclusions:
DME patients can have reduced reading speed despite good visual acuity. In this study, as one would expect, we confirmed that maximal reading speed is reduced in older patients and those with poor vision. However, MRS is not related to OCT findings. This is consistent with previous observations that retinal thickness is not a good indicator of retinal function in DME patients. MRS is often reported to be difficult to perform, inconsistent, and affected by language and educational level. However, in this study, we found that the central MP5 points are quick and easy to test in the majority of patients, and are highly correlated with MRS. MP5 might therefore be able to replace reading function in the assessment of DME patients.
Keywords: 499 diabetic retinopathy •
505 edema •
672 reading