BKC and CME: Is benzalkonium chloride hindering our efforts to achieve the desired postoperative visual acuity?

To evaluate and compare the change in postoperative central macular thickness in patients receiving benzalkonium chloride (BKC)-preserved and BKC-free medications after uneventful phacoemulsification.

V.M.M.C & Safdarjung Hospital, New Delhi (a tertiary health care hospital).

Prospective randomized comparative observational study.

Once patients were selected, the baseline standard ophthalmic examination was done.

140 eyes were enrolled and randomly divided into two groups. (a) Group I: receive BKC-preserved topical medications and (b) Group II: receive BKC-free topical medications of same constituents postoperatively. Group I patients received topical BKC-preserved moxifloxacin 0.5% + dexamethasone 0.1% eye drops six times a day, timolol maleate 0.5% twice daily, tropicamide 0.8% + phenylephrine 5% once a day for 6 weeks, and Group II received same BKC-free topical eye drops for 6 weeks. Postoperatively, the patients were reviewed at day 1, week 1, week 6 for same parameters.

Quantitative variables: paired and unpaired t test. p value < 0.05 was considered statistically significant.

The mean CMT in μm at 1 week in Group I was 269.39 ± 14.56 and in Group II was 270.04 ± 6.56. The mean CMT in µm at 6 weeks in Group I was 270.39 ± 17.18 and in Group II was 270.90 ± 7.00.

Neither do BKC-preserved topical medications have any independent role in increasing the central macular thickness after uneventful surgery nor do they have any role in causing pseudophakic CME.