Ocular Hypotony Rate Higher After Dexamethasone Implant Than Triamcinolone

Ocular hypotony was more common among patients who received a dexamethasone implant than those who underwent intravitreal triamcinolone injections for postoperative macular edema.

Ocular hypotony rates are higher among eyes that receive dexamethasone implants compared with those that receive intravitreal triamcinolone for postoperative macular edema following vitrectomy, according to a poster presented at the American Society of Retina Specialists meeting, held in Seattle, July 28 to August 1, 2023. 

Presenter Bita Momenaei, MD, discussed the research conducted by a team from Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University. They reviewed ocular hypotony rates and other types of complications in eyes following dexamethasone implantation (0.7 mg) or intravitreal triamcinolone (2 mg) for the treatment of macular edema following vitrectomy.

The retrospective case series included 148 eyes (147 adult patients), 75 in the dexamethasone group and 73 in the intravitreal triamcinolone group. Included patients had received either treatment for post-vitrectomy macular edema between July 2014 and December 2021 and underwent at least 3 months of follow-up (2.5±1.6 years). Eyes were excluded if they received both treatments because of switches in the follow-up period.

Data was analyzed with the Mann–Whitney rank-sum test, Student’s t-test, chi-square test, and Fisher’s exact test.

The incidence of ocular hypotony, which causes transient visual impairment, was significantly higher in vitrectomized eyes treated with dexamethasone, compared with eyes treated with intravitreal triamcinolone.

Dexamethasone was associated with a higher transient Ocular hypotony rate per eye and per injection (10 eyes [13%], 30/443 injections [7%]) intravitreal triamcinolone 2 eyes [3%], 2/262 injections [0.8%]). Mean visual acuity dropped at ocular hypotony. A median of 12 days following resolution of hypotony, visual acuity was restored to the level it was at before injection, without surgery.

Vitreous hemorrhage, rhegmatogenous retinal detachment, and ocular hypertension incidence rates were not statistically significantly different between the groups. Ocular hypertension (>24 mm Hg per eyes) occurred in 31% of eyes in the dexamethasone group and 22% of the eyes in the intravitreal triamcinolone group (P =.307). Dexamethasone implant migrated into the anterior chamber in 4 eyes.

An elevated rate of ocular hypertension among the dexamethasone group compared with the intravitreal triamcinolone group was not statistically significant.

“The incidence of ocular hypotony, which causes transient visual impairment, was significantly higher in vitrectomized eyes treated with dexamethasone, compared with eyes treated with intravitreal triamcinolone. Injections other than the inferotemporal quadrant or rotating injection sites may be recommended,” Dr Momenaei explained.  

Disclosure: Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

References:

Momenaei BA, Wakabayashi T, Liu CK, et al. A comparison of ocular complications after 0.7-mg dexamethasone implant versus 2 mg of intravitreal triamcinolone in vitrectomized eyes. American Society of Retinal Specialists (ASRS) 41st Annual Meeting; July 28-August 1, 2023; Seattle.