Study Links Increases in RRD, Myopia Incidence

An increase in primary rhegmatogenous retinal detachment incidence (RRD) may be associated with a simultaneous increase in myopia (nearsightedness) among citizens residing in the Netherlands, according to study results published in JAMA Ophthalmology.

RRD develops from retinal breaks occurring at points of firm vitreoretinal adhesion and dynamic traction on the retina, such as during posterior vitreous detachment, researchers explained. The condition is one of the most common sight-threatening emergencies throughout the Western world, as even with timely surgery, an RRD can result in severe visual impairment.

To determine if the 2016 incidence rate of RRD in the Netherlands compares with that of 2009, and to identify trends in RRD risk factors in the Dutch population over the same time, researchers analyzed 2 national data sets. Data from all 14 vitreoretinal clinics in the Netherlands and data from a large Dutch population-based cohort study (Rotterdam Study) were included in the analysis.

In the Netherlands, all patients with diagnosed RRD are referred to 1 of the 14 centers included in the study (Dutch RRD Study Group). The Rotterdam Study consists of all inhabitants aged 45 years and older residing in a Rotterdam district (72% response rate; n = 14,926) making it representative of the middle and elderly Dutch populations. As part of the Rotterdam Study, all participants underwent an extensive ophthalmological examination.

Patients who received RRD surgery between 2016 and 2017 (defined as receiving conventional surgery, pars plana vitrectomy or pneumatic retinopexy) were included in the Dutch RRD Study Group. “RRD was defined as a retinal detachment with a retinal break, detected before or during surgery,” the researchers wrote, while “tractional, exudative, and traumatic retinal detachments were excluded, as was any prior retinal detachment in the same eye.”

Overall, in 2016, 4447 Dutch individuals with a primary RRD underwent vitreoretinal surgery, resulting in an annual incidence rate of 26.2 (95% CI, 25.4-27.0) per 100,000 person-years. Patients had a median age of 61 years. Thirty-six (0.8%) of these individuals also developed bilateral primary RRD within the same year.

In terms of migration, the population of the Netherlands remained largely stable within the study window. Because all legal residents are obliged to enroll in a collective health insurance system, the risk of missed RRD cases was minimized in the current study.

Analyses revealed:

• In 2016, overall RRD incidence rate increased by 44% compared with similar data from 2009
• The incidence rate was highest in the age categories 55 to 59 years (76.2 per 100,000 person-years) and 60 to 64 years (78.7 per 100,000 person-years)
• Of 4447 cases, 2975 (66.9%) were male and 1472 (33.1%) were female
• Increases from 2009 to 2016 were observed in both phakic (1994 to 2778; 39%) and pseudophakic eyes (1004 to 1666; 66%), suggesting cataract extraction did not solely account for the overall rise
• Between 2009 and 2016, prevalence of mild, moderate, and severe myopia among persons aged 55 to 75 years increased by 15.6% (881 of 4561 [19.3%] vs 826 of 3698 [22.3%]), 20.3% (440 of 4561 [9.6%] vs 429 of 3698 [11.6%]), and 26.9% (104 of 4561 [2.3%] vs 107 of 3698 [2.9%]), respectively data from the Rotterdam Study show

“An increase in myopia prevalence may be an alternative explanation for the rise in incident RRD cases after 2009,” the researchers hypothesized. The coincidence does not prove a causal relationship between the 2 conditions and further studies in other countries are needed to confirm the findings.

“The link between myopia and RRD may involve a posterior vitreous detachment. Myopic eyes experience a posterior vitreous detachment at an earlier age and with a higher risk of retinal breaks,” the authors wrote. “The latter may be explained by a thinner retina, both in the equatorial and pre-equatorial region, with myopic axial globe elongation.”

Previous reports have also demonstrated a shift to more myopia in recent birth cohorts around the world. “Consequently, the increase in RRD incidence in the Netherlands may be even larger in the future, which should alert policy makers in future health care planning,” the researchers said.

A relatively limited period of data collection (within 1 year) and the lack of data on refraction or axial length of the incident RRD cases mark limitations to the study. Future studies ought to include this risk factor in the case description, the authors concluded.

Reference

van Leeuwen R, Haarman AEG, van de Put MAJ, Klaver CCW, and Los LI. Association of rhegmatogenous retinal detachment incidence with myopia prevalence in the Netherlands. JAMA Ophthalmol. Published online November 25, 2020. doi:10.1001/jamaophthalmol.2020.5114