Cataract Surgery Destabilises Temporary the Tear Film of the Ocular Surface

Background Symptoms due to dry eye in the form of kerato-conjunctivitis sicca (KCS) are often seen after cataract surgery. We investigated the influence of cataract surgery on tear film stability on the ocular surface. Material and Methods 60 eyes of 60 patients who underwent cataract surgery were included in a prospective study in 2017 at the Eye Hospital in Hanoi (Vietnam National Institute of Ophthalmology). The mean age of the patients was 65 +/- 10 years. The phacoemulsification was performed under topical anaesthesia by a clear corneal incision and implantation of a foldable IOL. The parameters for the evaluation of the change of the tear film included subjective patient data using the Ocular Surface Disease Index questionnaire (OSDI), findings of the Schirmer I test, the tear break-up time (TBUT) as well as the tear meniscus height (TMH) measured noninvasively with the Keratograph 5M (Oculus). In addition, conjunctival and corneal changes were examined after vital staining with fluorescein for the cornea and rose bengal for the conjunctiva. Data were collected preoperatively, at 1 week, 1 month and 3 months postoperatively. According to DEWS, the disease is classified into 4 groups: mild, moderate, severe and very severe. Results One week after surgery, the total score according to OSDI was significantly increased with a total value of 14.4 +/- 4.2 (p = 0.001). Schirmer I was 15.8 +/- 4.3mm preoperatively and decreased significantly in the first postoperative week (p = 0.001), before reaching the preoperative level again after three months. TBUT was 12.6 +/- 1.5 s preoperatively, decreased significantly to 9.7 +/- 1.5 s during the first postoperative week, and normalized to 12.4 +/- 1.3 s by the end of the third month. The meniscus height was 0.245 +/- 0.055 mm preoperatively, significantly lowered to 0.229 +/- 0.057 mm in the first postoperative period and nearly normalised by the third postoperative month to 0.241 +/- 0.051 mm. In the first postoperative week, the rate of mild KCS was observed in 30% of patients. At one month, this decreased to 10% and at three months was no longer demonstrable in any patient. Conclusion One of three patients experienced mild KCS after cataract surgery. The symptoms lasted up to three months. This should be taken into account preoperatively and appropriate therapy should be planned.