Purpose: To identify any changes in corneal sensitivity and tear physiology after phacoemulsification and to evaluate the effectiveness of the use of ophthalmic lubricants.
Methods: The design of the study was longitudinal, parallel, randomised and double masked. Eighteen patients (average age 70.83 +/- 10.66 years, 7 males and 11 females) undergoing phacoemulsification were recruited and divided into three groups of six. In addition to the prednisolone acetate 1% and chloramphenicol 0.5% routinely given to patients postoperatively, the first two groups were given a tear lubricant (Refresh Soothe and Protect, Allergan Inc., Irvine, CA, USA) and saline (Chauvin Pharmaceuticals Ltd, Essex, UK), respectively, and the third was a control group and did not receive any additional eye drops. Tear production, evaporation, lipid layer interferometry and osmolarity along with corneal sensitivity were measured before and 3 days, 2 weeks, 1 month and 3 months after the surgery.
Results: Statistically significant detrimental changes were seen in all parameters of corneal sensitivity and tear physiology immediately after phacoemulsification. Tear physiology recovered within 1 month. Corneal sensitivity did not return to normal levels in 3 months, but a trend towards full recovery was seen. Saline and the tear lubricant were not found to have an effect on the improvement of tear physiology and corneal sensitivity post-surgically.
Conclusions: Deterioration in corneal sensitivity and tear physiology is seen immediately after phacoemulsification. Corneal sensitivity does not return to preoperative levels until 3 months postoperatively whereas the tear functions recover within 1 month.