I find this paper “Dry Eye After Cataract Surgery and Associated Intraoperative Risk Factors” by Yang Kyeung Cho, MD, PhD1 and Man Soo Kim, MD, PhD very informative. The entire article is on this web page http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2694295/.
To investigate changes in dry eye symptoms and diagnostic test values after cataract surgery and to address factors that might influence those symptoms and test results.
In the dry eye group, there were significant aggravations in Sx at 2 months postoperatively and in TMH at 3 days, 10 days, 1 month, and 2 months postoperatively, compared with preoperative values. All dry eye test values were significantly worse after cataract surgery in the non-dry eye group. With regard to incision location, there was no difference in tBUT, Sx, ST-I, or TMH in either the dry eye group or the non-dry eye group at any postoperative time point. Regarding incision shape, there was no difference in tBUT, Sx, ST-I or TMH at any postoperative time point in the dry eye group. In the superior incision sub-group of the non-dry eye group, tBUT and Sx were worse in the grooved incision group at day 1. In the temporal incision sub-group of the non-dry eye group, Sx were worse in the grooved incision group at 1 day, 3 days, and 10 days postoperatively. In both groups, significant correlations were noted between microscopic light exposure time and dry eye test values, but no correlation was noted between phacoemulsification energy and dry eye test values.
Cataract surgery may lead to dry eye. A grooved incision can aggravate the symptoms during the early postoperative period in patients without dry eye preoperatively. Long microscopic light exposure times can have an adverse effect on dry eye test values.
Dry eye sensation frequently occurs after cataract surgery. Affected patients may experience red or watery eyes and constant foreign body sensation. Lesions such as superficial punctate keratitis and epithelial defects may be seen on the cornea.
Generally, the etiology of dry eye following cataract surgery is characterized by one of two mechanisms.1 One patient group experienced an increase in pre-existing dry eye symptoms and the other group experienced surgically-induced dry eye. There are many factors that might affect the ocular surface environment after cataract surgery. Topical anesthesia and eye drops containing preservatives like benzalkonium chloride are well known to have effects on the corneal epithelium.1,13 Exposure to light from the operating microscope might also be associated with postoperative dry eye.1 Most corneal surgical procedures disrupt the normal organization of the corneal innervation, and this results in pathologic changes of the cornea and attendant discomfort.