Researchers recently examined IRIS Registry data to assess factors associated with laser trabeculoplasty (LTP) responses. The retrospective cohort study included 263,480 eyes that underwent LTP for glaucoma. Eyes that achieved a less than 20% IOP reduction after eight weeks were considered non-responders, while responders experienced a greater than or equal to 20% IOP reduction.

In the cohort, the mean baseline IOP was 19.1±5mm Hg and participants were on a mean of 2.1±1.5 medications before the laser procedure. Overall, the researchers reported a response rate of 36.9%, with a 68.8% response rate for those with a baseline IOP greater than 24mm Hg. They noted that a higher baseline IOP was associated with reduced odds of non-response, while angle recession, uveitis and aphakia increased the odds of a non-response. 

Only 19.6% of eyes in the study had no preoperative medications; of those on at least one medication at baseline, 76.3% saw a reduction in the number of medications post-op.

The researchers concluded that further studies in LTP responder survival and implementation lag would optimize resources in glaucoma therapy.

Chang TC, Parrish RK, Fujino D, et al. Factors associated with favorable laser trabeculoplasty response: IRIS Registry Analysis. Am J Ophthalmology. October 10, 2020. [Epub ahead of print].