Abstract
Purpose:
To assess the prevalence and severity of ocular surface disease symptoms and signs in glaucoma patients
Methods:
Glaucoma subjects (n=64) and age matched controls (n=59) underwent a full ophthalmological examination including visual acuity and visual field examination, tear film break-up time (TBUT, in seconds), corneal staining score (using National Eye Institute scale), and Schirmer’s test with anesthesia. The Ocular Surface Disease Index (OSDI) questionnaire was administered to assess symptoms. A total OSDI score, vision-related subscore (derived from questions about vision/task performance), and discomfort-related subscore (derived from questions about ocular surface discomfort) were calculated for each subject.
Results:
Total corneal staining grade was greater in glaucoma subjects than controls (6.4 vs. 4.1, p<0.001), but the groups did not differ significantly in TBUT or Schirmer’s test (p>0.20 for both). Multivariable linear regression showed that glaucoma therapy burden was associated with a higher total corneal staining grade (β=+0.9 for each additional glaucoma drop; 95% CI=0.5-1.3; p<0.001), but not with TBUT or Schirmer’s test (p>0.20 for both). Glaucoma subjects had significantly higher total OSDI scores than controls (16.7 vs. 7.9, p<0.001), largely due to higher vision-related subscores compared to controls (11.1 vs. 3.3, p<0.001). Despite greater corneal staining scores in glaucoma patients, ocular discomfort-related subscores were similar in both groups (5.7 vs. 4.6, p=0.30). In multivariable analyses, each 5 decibel decrement in better-eye visual field mean deviation was associated with a 4.7 point increase in total OSDI score (95% CI=1.9-7.5; p=0.001) and a 3.7 point increase in the vision-related subscore (95%CI=1.7-5.6; p<0.001), but did not predict a higher discomfort-related subscore (β=1.1 point, p=0.07).
Conclusions:
Glaucoma is associated with significant ocular surface disease. The extent of glaucoma therapy seems to be predictive of severity of corneal staining. Although glaucoma patients report higher OSDI scores, this seems to be largely related to visual field loss, producing greater vision-related symptoms or difficulty with daily activities such as reading and driving. Therefore, total OSDI score may not be an appropriate means of assessing ocular surface disease in glaucoma patients. Further study is needed to establish other reliable methods to be utilized in this susceptible population.
Keywords: 463 clinical (human) or epidemiologic studies: prevalence/incidence