Predictors Of Tear Film And Ocular Surface Disruptions After Cataract Surgery: An Exploratory Study

To study the various baseline factors contributing to ocular surface damage after uneventful cataract surgery and to develop a plan for rational use of ocular surface protectors before and after cataract surgery.

A Prospective non-randomised double masked comparative clinical trial conducted in the department of Cornea & Ocular surface diseases, at a Tertiary Eye Institute in South India.

200 cases of age related cataracts with and without Diabetes Mellitus were recruited. Preoperative evaluation of Meibomian gland morphology and the functional tear film using, automated quantitative non-invasive measurements including the tear meniscus studies, non-invasive tear break-up time, blink rate and meibography would be analysed and compared with 21 days and 3 months post surgery. Ocular Protection Index (OPI) was calculated as a function of ocular surface health by dividing tear break up time by interblink interval and analysed each visit. OPI of less than 1.0 is considered as ocular surface damage. Using logistic regression a mathematical formula was constructed to understand various factors contributing ocular surface damage.

Mean OPI was 1.3758 (0.61) at baseline, 0.9738 (0.97) at 21 days and 1.1038 (0.62) at 3 months. Repeated measures ANOVA showed a significant time effect (p<0.001). Mean blink interval was 7.91 (2.73) at baseline, 8.82 (4.04) at 21 days & 9.39 (2.98) at the end of 3months p<0.0001). Age adjusted DM influence on meibomian gland loss was 12.1% compared to non-DM 6.64%. A logistic regression model to ascertain the effects of DM and age on OPI was statistically significant, chi square=11.588, P=0.003. It explained 23.6% (Nagelkerke Rsquare) of the variance in treatment response and correctly classified 78.5% of cases. Elderly subjects, diabetics were 6.29 & 1.79 times more likely to sustain surface damages than their counterparts respectively.

Subjects over 60 years of age, irrespective of concomitant DM had borderline OPI, and are susceptible to develop ocular surface damages post cataract surgeries. Subjects with DM irrespective of age had borderline OPI, and are highly susceptible to develop ocular surface damages following cataract procedures. Subjects who are over 60 years with concomitant DM had OPI below normal and could develop surface damages even without cataract procedures and require a long-term ocular surface protectors