XFG was defined as the presence of PXM on the anterior lens capsule or pupillary margin, elevated IOP ([greater than or equal to]21 mmHg), glaucomatous optic disc changes (vertical cup-to-disc ratio [C/D] [greater than or equal to]0.5, C/D asymmetry [greater than or equal to]0.2), characterized visual field defects in computed perimetry (Zeiss Humphrey visual field analyzer white-to-white 30-2 threshold program).
A total of 277 individuals (58 XFG, 48 XFS, 171 controls) over 40 years old were recruited for this study in Eskisehir Osmangazi University Department of Glaucoma.
In both XFS and XFG, a strong association with the risk allele of each individual SNP (rs2165241T, rs1048661G, and rs3825942G) was observed (Table 2).
According to previous studies, females are affected by XFS more often than males, whereas XFG is more severe in males than females.
(10,11,12,13,14,15,16,17,18,19,20,21,22) In the present study the G allele and GG genotype of rs3825942 was present in all XFS and XFG cases.
In several studies researching whether LOXL1 gene polymorphism has any role in predicting XFG development, no significant association was found in the differentiation of XFS and XFG.
The main inclusion criteria were the appearance of unilateral or bilateral XFS and the existing bilateral XFG.
In this study, XFS subjects were those without glaucomatous disc changes or VF defects, while XFG subjects also had these changes and treatable IOP besides exfoliation.
In the bilateral XFG group, there were 14 (50.00%) men and 14 (50.00%) women.
The mean ([+ or -]SD) age was 80.39[+ or -]4.04 years in the bilateral XFS group; 77.67[+ or -]5.79 in the unilateral XFS group; 71.25[+ or -]5.96 in the bilateral XFG group; and 75.69[+ or -]5.68 in the control group of healthy subjects.
In the XFG group, 7 of 56 (12.5%) eyes had normal RNFL thickness in inferior quadrant, 20 of 55 (35.71%) eyes in superior quadrant, 52 (92.86%) eyes in nasal quadrant, and 39 (69.64%) eyes in temporal quadrant.
Analysis of the mean RNFL thickness showed that the smallest number of eyes were within the reference values in the XFG group (9 of 56; 16.07%), followed by bilateral XFS (32 of 48; 66.67%) and unilateral XFS (the same percentage in clinically visible and fellow eye, 22 of 30; 73.33%).