Over the past decade, the global incidence of rhegmatogenous retinal detachment (RRD) has increased and may be associated with a coincidental increase in the risk factors of RRD.¹ To confirm the key RRD risk factors affecting the Dutch population, researchers from the Dutch Rhegmatogenous Retinal Detachment Study Group have evaluated the incidence of RRD in the Netherlands over a 7-year period and found that the increasing RRD incidence may be associated with a simultaneous myopic shift.¹ As other known RRD risk factors such as age distribution and cataract surgical rate could not solely explain the rising incidence of RRD among the Dutch population, further population-based studies are warranted to better understand the association between RRD incidence and global myopia prevalence.¹

Affecting 18.2 persons per 100,000 population in the Netherlands, RRD is the most common form of retinal detachment that occurs when fluid gains access into the subretinal space through a retinal tear^.1,2 Myopia, which accelerates posterior vitreous detachment (PVD) that commonly precedes RRD, can increase the risk of developing RRD by 10-folds among those with myopia of over 3 dioptres.^2,3 Similarly, the prevalence of PVD is associated with an aging population; where 27% of patients aged 60-69 were found to have PVD, the prevalence was increased to 63% among those over the age of 70.3 On the other hand, cataract surgery is also a known risk factor for RRD with approximately 1 in 5 RRDs being pseudophakic.²

To determine the relationship between the change in RRD incidence and the prevalence of these RRD risk factors in the Netherlands, Dr. Redmer van Leeuwen from the Department of Ophthalmology, University Medical Center Utrecht, the Netherlands and his team have evaluated Dutch RRD patients, from 14 vitreoretinal clinics in the Netherlands, who have undergone vitreoretinal surgery in the year of 2009 and 2016.¹ In addition, the change in prevalence of myopia was estimated from the prospective population-based Rotterdam Study that included 14,926 Rotterdam inhabitants at the age of 45 years and older.¹

Previously reported by the investigators, 2,998 RRD patients from the Netherlands underwent surgery in 2009, which is equivalent to an annual RRD incidence of 18.2 per 100,000 person-years.⁴ Whereas the Dutch population had only increased by 3% from 2009 to 2016, the number of RRD patients who underwent surgery in 2016 has increased to 4,447, representing a 44% increase in annual RRD incidence rate that is equivalent to 26.2 per 100,000 person-years.¹

While age is a known risk factor for RRD, the age-specific incidence rates in 2016 were not significantly different than the observed numbers in 2009.^1,3 The median age of RRD patients was similar, at 61 years and 60 years, between 2016 and 2009 respectively, indicating that age distribution cannot solely explain the increase in RRD incidence among the Dutch population.¹ Likewise, despite an increase in cataract surgery from 55.9 per 10,000 persons in 2000 to 88.5 per 10,000 persons in 2009, the overall ratio of phakic to pseudophakic RRD actually decreased from 2.0 in 2009 to 1.7 in 2016.¹ Similar to age distribution, cataract extraction could not solely account for the overall increase in RRD incidence.¹

Conversely, the Rotterdam Study showed that, from 2009 to 2016, there was a 15.6%, 20.3% and 26.9% increase in low, moderate and high myopia, respectively, among the Rotterdam inhabitants aged 55 to 75.¹ In the same period, this increasing trend of myopia was consistently observed in both genders with a 2.3% and 2.0% increase among male and female individuals, respectively.¹ While this coincidence did not prove a causal relationship, the global rising trend of myopia among recent birth cohorts warranted further population-based studies to determine the causation between RRD incidence and global myopia prevalence.¹

Indeed, a recent local study has reported a myopia prevalence of 25.0% among Hong Kong children aged 6 to 8 years with 72.2% of their parents also having myopia.⁵ With the local prevalence being much higher than other regions of China, policies to prevent myopia should be noted in future healthcare planning to limit further increase in RRD incidence.^1,5 “The myopic shift among younger age groups will be stronger. Consequently, the increase in RRD incidence in the Netherlands may be even larger in the future, which should alert policymakers in future health care planning,” concluded Dr. van Leeuwen.