Abstract
Purpose :
Very little information is known about the incidence of dry-eye disease (DED) in developing countries in contrast to industrialized populations. Some studies have largely related DED in those areas to vitamin A deficiency and infectious diseases (Trachoma). However, as many developing countries have recently transitioned (some still transitioning )into emerging economies such transformations may impact disease and health including DED. Our purpose was to evaluate the epidemiology of DED particularly regarding the differences between rural and urban populations.
Methods :
Using a custom made meibographer, meibographs were captured of upper and lower lids of 111 subjects (45males,mean age = 48.0± 22.99) visiting two ophthalmic practices (1 rural,1 urban) in Ghana. Meibomian gland (MG) area was determined by intensity threshold segmentation and calculated with ImageJ software. Meibomian Gland Loss (MGL) was quantified by outlining its area and expressing it as a percentage of the total MG area. Additionally Schirmer’s test, Ocular Surface Staining (OSS) and tear break-up time (TBUT) were measured and symptoms were evaluated with the SPEED II questionnaire. Spearman rank correlation was performed to determine the relationship between MGL and the clinical variables. Differences between groups were analyzed using Mann -Whitney U and Chi-square tests. P< 0.005 was considered significant.
Results :
Average MGL was higher in rural populations than urban populations for the upper lids (31.05 %±27.28 vs 17.96 %±22.01 U=1988.5, p =0.008) and lower lids (34.04±29.24 vs 20.00 ±24.90 U=1986.5, p = 0.008). All other clinical DED parameter but TBUT differed significantly between rural and urban populations (U =1195.5,p=0.043). Overall, there were significant correlations between MGL and age ( rs = 0.82, p =0.001),TBUT (rs = -0.72, p < 0.001), Schirmer’s scores (rs = -0.68, p < 0.001) and OSS (rs = 0.59, p < 0.001). However, there was insignificant correlation MGL and SPEED II score (rs = 0.02 p= 0.84)
Conclusions :
This is the first study that systematically investigated MGL in an African population. While MGL correlated with most clinical signs, to our surprise MGL was greater in the rural population; which may be due to higher rate of recurrent eye infections. Results show similarities to previous studies from developed countries, including lack of correlation between signs and symptoms..
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.