Clear corneal incisions used in phacoemulsification sever ophthalmic nerve endings, which are responsible for sensory innervation of the cornea. This trauma leads to decreased stimulation necessary for tear production, eventually resulting in dry eye disease. Other, not less important factors include topical anesthesia, preservatives in eye drops used during and after surgery, microscope light toxicity, frequent irrigation, older age group, prolonged phaco time and many other factors [1]. Dry eye disease is difficult to treat, with time becomes chronic and complicated, while measures undertaken to prevent its incidence may result in far better results. We chose to benefit from temporary punctal plugs as they resolve within 60-80 days after implantation, which is the time needed for corneal nerve fibers to regenerate [1], [2]. The upper punctum is responsible for 30 % of tear film drainage, after being occluded the inferior punctum compensates, resulting in 20% retention of tear film, which is about the same amount of average decrease in FTBUT one week after surgery (22.60%) according to control group in our study (tab. 4).
Implanting temporary punctal plugs DURAPLUGS – EAGELVISION resulted in an important increase in visual acuity in the first (study) group, compared to second (control) group in all follow up periods ( one day, one week, one month ) after surgery ( tab.2). These results might be explained by the role of punctal plugs in tear film function improvement and prevention of dry eye disease. Meniscus height improvement in the first group compared to second was evident one day and one week after surgery, while the difference was not evident one month after surgery (tab. 3). Similar results were obtained regarding FTBUT(tab. 4), which became better in the first group compared to the second one week and one month after surgery, but the difference was statistically evident only one month after surgery. Meniscus height results might be due to reflex tearing during the first week caused by surgical trauma, which augmented tear retention effect of the punctal plugs, thus increasing meniscus height difference between the two groups, while FTBUT difference between the two groups became evident only one month post- surgery after recession of reflex tearing. Occluding only one punctum (upper), led to a favorable moderate balanced increase in tear film retention, seen one month after surgery in eyes implanted with temporary punctal plugs. We presume that punctal plugs compensated decreased lacrimal film function seen in eyes without implants.
Patients treated with temporary punctal plugs might experience foreign body sensation or irritation, so we investigated patient's satisfaction, as to whether they had foreign body sensation or irritation. Results showed that the difference was not evident between the two groups, which might be related to surgical trauma that super imposed the suspected probable irritating effect of punctal plugs. We have not encountered any case of canaliculitis or retention of lacrimal plugs or any other complications in the lacrimal system even in patients seen during 10 years after surgery. This might be due to exclusion of patients with any eye or lacrimal system infections or pathologies, in addition to implanting punctal plugs in the sterile operating room environment.
Post-phaco dry eye disease is a chronic, difficult to treat complication, often leads up to disappointing results [1]. We suggest a new approach for dealing with it, using preventive measures, as prevention is better than treatment.