Effect of Tear Film Changes on Visual Acuity after Uncomplicated Phacoemulsification Cataract Surgery

The aim of the study was to show the effect of tear film instability after uncomplicated ultrasound phacoemulsification cataract surgery in patients without previous tear film instability and to show its impact on the best corrected visual acuity (BCVA) one month after the surgery. The prospective cohort study included 30 patients of both sexes with cataract who underwent uncomplicated ultrasound phacoemulsification cataract surgery. Exclusion criteria included pre-existing ocular surface disease and tear film instability, topical antiglaucoma therapy, lid disorders, punctate epitheliopathy, corneal disorders, post-surgical corneal tear film instabilities, traumatic corneal scars, diabetic patients, posterior segment diseases and retinal surgeries, maculopathy, as well as previous or active uveitis that could compromise postoperative BCVA. All patients underwent full ophthalmic examination, corneal fluorescein staining, tear film break-up time test (TBUT) and visual acuity assessment on the day of surgery and 30 days after surgery. The difference in TBUT before and after phacoemulsification cataract surgery and difference in BCVA before and after cataract surgery were examined. All patients underwent ultrasound phacoemulsification cataract surgery followed by monofocal intraocular lens implantation performed by the same surgeon. The mean age of patients was 73±7 years. The study included 53% of female patients, with no statistically significant sex difference (Fisher exact test, p=0.72). BCVA was significantly improved after phacoemulsification cataract surgery with preoperative median BCVA 0.2±0.1 and postoperative median BCVA 1.0 (-0.1) (Wilcoxon test, p<0.001). TBUT was significantly worse in comparison to preoperative measurements. Preoperative median TBUT was 10±2 s. Postoperatively, 6 out of 30 patients had TBUT <5 s and 24 out of 30 patients had TBUT measurements between 6 and 10 s (Wilcoxon test, p<0.001). Fluorescein staining was negative preoperatively in all patients and positive in 10 out of 30 patients after surgery. Subjective symptoms of dry eye after surgery were reported by 5 out of 30 patients (TBUT <5 s and positive fluorescein staining). There was no significant difference in visual acuity considering dry eye symptoms (p=0.51, Mann-Whitney U test). The present study showed that uncomplicated phacoemulsification cataract surgery influenced tear film instability, worsened TBUT measurement and corneal fluorescein staining, but fortunately with no statistically significant impact on postoperative BCVA one month after surgery.