Population studies

IRIS Registry update

Population studies illuminate rare conditions, outcomes and disparities in care. Howard Larkin reports

AAO’s Intelligent Research in Sight IRIS® Registry is living up to its promise of shedding light on low-incidence occurrences and broad population trends. Launched in 2014, the IRIS Registry is the USA’s first comprehensive eye disease registry. It currently includes data from nearly 66 million unique patients and 367 million patient visits.

At AAO 2020 Virtual conference, more than 20 papers, posters and presentations featured IRIS Registry-based research ranging from surgical outcomes in rare conditions to demographic disparities in outcomes for more common conditions.

RARE CONDITIONS On the rare condition end of the spectrum, an AAO Best Poster winner by Peter J Belin MD and Polly A Quiram MD, PhD, of Minneapolis, USA, examined treatment patterns and outcomes of paediatric retinal detachments (RD) associated with hereditary vitreoretinal degenerative diseases including Stickler and Marfan syndromes. Looking for cases of rhegmatogenous RDs in patients aged 18 or younger from across the USA, from 2013 through 2018 they found a total of 421 eyes of 353 patients with one year or more of follow-up.

Among the findings were that patients underwent a mean 1.98 surgeries per eye in one year, with higher rates of additional surgeries required in eyes that initially underwent complex RD repair at 41% than for pars plana vitrectomy at 26%, or scleral buckle at 15%. Powered by IRIS Registry, this outcomes study provides insight into the variability of technique in this small population that may not be available examining results from a single centre, the authors said.

In another study of sympathetic ophthalmia, a rare, bilateral granulomatous uveitis resulting from autoimmune reaction to antigen exposure during trauma or surgery, Nathan Eli Hall BS, MS, of Harvard University, found that women are at higher risk than men, accounting for 66.71% of cases. The study identified 817 cases among 70 million records, and determined the most frequent precipitating procedure was cataract surgery at 89.73%, with women at significantly higher risk in this subcategory as well.

LARGE POPULATION STUDIES On the large population end of the spectrum, a poster by Bret L Fisher MD and colleagues of Panama City, Florida, USA, compared the mean time to posterior capsule opacification (PCO) in different types of IOLs implanted in 43,032 eyes with two years or more of follow-up from 2016 to 2018. Overall. 35.7% of eyes had a diagnosis of PCO after two years or more, with a mean time to diagnosis of 268 days after surgery. Multifocal and extended depth of focus lenses had a shorter time to PCO compared with monofocals, while hydrophobic acrylic lenses by two large manufacturers showed differing mean lengths of time to PCO, with 269 days for Tecnis (Johnson & Johnson) compared with 300 days for AcrySof (Alcon).

An IRIS Registry study comparing glaucoma patients who received the first-generation iStent trabecular bypass device as a standalone procedure with those who received it combined with cataract surgery was presented by Robert T Chang MD, of Stanford University, Palo Alto, California, USA. It found that standalone patients were more likely to have had previous ocular procedures including cataract surgery, nonfiltering and filtering glaucoma surgery, and laser treatments than combined patients, and had more moderateto-severe disease than the combined group. The study involved 995 standalone and more than 187,000 combined surgery patients operated on from 2013 through early 2020.

Nearly 2.7% of eyes in the USA with pathologic high myopia (PHM) experienced retinal detachments between 2013 and 2018, according to an IRIS-powered study by Danielle Fujino MPH of the California, USA, Department of Public Health, Flora Lum MD, of the Academy and Scott P Kelly of Pfizer Inc. Of 461,281 eyes in 249,381 patients with PHM, 12,402, or 2.69%, had retinal detachments during the period. Eyes with glaucoma prior to myopia or vitreous degeneration prior to myopia were more likely to experience RD, as were patients in the Midwest or western regions.

DEMOGRAPHIC DETERMINANTS Several studies examined demographic and social determinants of health in eye care. One study involving 203,673 patients looked at baseline and outcomes findings for diabetic macular oedema patients who received at least one anti-VEGF injection. Nisha A Malhotra, Rishi P Singh MD and colleagues at the Cleveland Clinic, USA, found that Hispanic patients had fewer anti-VEGF injections and poorer visual outcomes than non-Hispanic patients, and more patients presented in the southern region of the USA. Those with private insurance had better visual outcomes than those on public insurance regardless of ethnicity or geographic location.

“With a growing pool of aggregated data, the IRIS Registry empowers ophthalmologists to recognise disease patterns, better define risk factors and identify effective treatment options for their patients,” said Dr Lum, Academy’s vice president of Quality and Data Science. “All IRIS Registry studies being presented at AAO 2020 Virtual this year reveal interesting and promising results for a better future in eye care.”

...women are at higher risk than men, accounting for 66.71% of cases Nathan Eli Hall BS, MS

With a growing pool of aggregated data, the IRIS Registry empowers ophthalmologists to recognise disease patterns, better define risk factors and improve prevention and treatment options for their patients Flora Lum MD