Pupil dilation for diabetic retinopathy screening carries low acute angle closure risk

medwireNews: Among more than 80,000 patients participating in a teleretinal diabetic retinopathy screening (TDRS) program, the risk for acute angle closure (AAC) after pharmacologic pupillary dilation was less than 1 in 40,000 per dilation, shows a study in JAMA Ophthalmology.

Assessing data from 84,008 US patients who underwent dilated fundus examination as part of a TDRS program in 2013–2024, researcher Lauren Daskivich (Department of Health Services, Los Angeles, California, USA) and colleagues say that they “identified a very low risk of AAC following pharmacologic dilation.”

They found that only four cases of AAC occurred within 14 days of pupillary dilation with tropicamide 0.5% or 1.0%, at an associated AAC risk of 2.4 per 100,000 dilations (0.002%) in at least one eye, or 4.8 per 100,000 patients (0.005%).

Daskivich et al say that “[p]harmacologic pupillary dilation is fundamental to comprehensive eye examinations and improves detection of retinal and optic nerve pathology, including diabetic retinopathy.” However, the procedure is not widely adopted by non-eye care professionals “primarily due to concerns about triggering an AAC attack.”

They claim that their study of a high-volume TDRS program serving a diverse safety net population “support[s] the overall safety of dilation in this setting,” and stress that “it is imperative to continue the discussion on how to balance the benefits of dilation for earlier and more accurate detection of eye disease against the very low risk of AAC after dilation.”

The study participants had a mean age of 55 years and 55% were women, with the majority (67.7%) of Hispanic ethnicity.  None of the patients had received care from an eye professional within the previous 12 months. A total of 168,796 dilations were performed, equating to a mean of 2.01 dilations per patient.

All four cases of ACC occurred in women with a phakic intraocular lens who presented with unilateral vision loss 1 day after TDRS dilation. All received prompt ophthalmic care resulting in good visual outcomes, including improved best-corrected visual acuity for three out of the four women.

The researchers also assessed the validity of the ICD–9 and ICD–10 codes used to identify and classify ACC, and found that among the four cases, three were correctly coded as AAC glaucoma and one as anatomical narrow angle, with no additional ACC cases identified following a manual review of the medical records during the 2 weeks studied as well as for up to a year after pharmacologic dilation.

In a linked editorial, Rachel Chong and Tin Aung, both from the National University of Singapore, note that the study “supports the general safety of routine pupil dilation for diabetic retinopathy screening,” but that “longitudinal assessment of [intraocular pressure] and monitoring of angle changes may still be useful to evaluate the effects of repeated dilation in patients undergoing regular teleretinal screening.”

Indeed, they conclude that “[t]he long-term evaluation of progression to [primary angle closure] or AAC with repeated dilation in high-risk patients remains a valuable endeavor for future studies.”

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JAMA Ophthalmol 2025; doi:10.1001/jamaophthalmol.2025.3162
JAMA Ophthalmol 2025; doi:10.1001/jamaophthalmol.2025.3249