Combined Subconjunctival Injection of Dexamethasone for the Management of Acute Primary Angle Closure: A Randomized Controlled Trial

Huang, W., Li, X., Gao, K., & Zhang, X. (2019). Combined subconjunctival injection of dexamethasone for the management of acute primary angle closure: A randomized controlled trial. British Journal of Ophthalmology; 0, 1-5.

This article is a randomized control trial published in 2019 that primarily examines the effect of a 425 mg dexamethasone subconjunctival injection in addition to a standard regimen of topical pilocarbine QID, timolol BID, brinzolamide BID, an alpha-2 agonist BID, acetazolamide 250 mg TID, and mannitol 250 mL QD compared to the standard regimen alone in the reduction of intraocular pressure (IOP) in the setting of acute angle closure glaucoma. Successful IOP reduction was considered if tonometry measured between 6 and 21 mmHg. Secondarily, the researchers measured complications between the treatment groups, intraoccular inflammation variables by slit-lamp biomicroscopy without pupil dilation, conjunctival erythema, and cilliary flush.

The two treatment groups each included 21 adult patients diagnosed with acute angle closure glaucoma for a total of 42 participants. Due to the injection vs no injection groups, the participants were not blinded, but the observers at each evaluation were blinded. IOP measurements and clinical assessments were done at baseline and 3, 6, 12, and 24 hours after initial treatment and clinical assessment.

The researchers found the following results:

• IOP at 24 hours was significantly lower in the dexamethasone group compared to the standard group (p = .017)
• Significantly higher success rate in the experimental group (p = .027), but all participants experienced some degree of improvement
• Significantly improved conjunctival erythema (p = .012) and cilliary flush (p = .048) in the experimental group
• Improved pain scale in the experimental group (p = .013)
• No complications observed in either group

One limitation of the study was that the sample size was extremely small, limiting the power of the result. Additionally, the study not initially being blinded might have allowed for bias, particularly with the measurements like conjunctival erythema, cilliary flush, and the inflammation variables that were more subjective on the part of the observers. Finally, the study was conducted outside of the United States, limiting its generalizability. Still, it is an interesting experimental model and worthwhile to explore further in the treatment of acute angle closure glaucoma.