July 1, 2020
By Xiao Nicole Liu, MOptm
PhD Candidate, Brien Holden Vision Institute
It is well recognized that having myopia increases the risk for developing a number of sight-threatening conditions, namely myopic macular degeneration (MMD), retinal detachment (RD), cataract and open angle glaucoma (OAG). To illustrate the pressing need for a holistic myopia management approach, Haarman et al. (2020) conducted a systematic review and meta-analyses of all observational studies performed from 1988 to 2019, calculated the precise estimates of risks per myopia category for sight-threatening conditions , and revealed their specific impacts on vision.
One of the most noteworthy findings of this study is that, unlike the previous public perceptions, risks of MMD, RD, cataract and OAG increased not only among the population with high myopia, but also for those with low or moderate myopia. Although less likely to develop bilateral low vision compared to high myopes, low and moderate myopic groups are still significantly susceptible to those complications. An astonishing 100 times higher risk of MMD were found in myopes, along with three times higher risk of RD and a doubled risk of OAG.
Additionally, the study revealed a strong relationship between severity of myopia, age of the patient, and visual impairment, which indicated a critical window for possible intervention. Taking the natural course of MMD as an example, significant vision losses were observed over a 10-year follow-up period. Therefore, the authors suggested that patients with severe myopia (10 diopters or greater spherical equivalent myopic refractive error) need to have ophthalmologic screenings at the age of 30, and patients with SER of -6 to -10 diopters need to have their screenings at age 50, in order to seize the opportunity to act for a better outcome.
To conclude, the authors wish to increase the alertness amongst patients, eye care professionals and policy makers to complications of myopia. This work highlighted the urgent need of a comprehensive strategy for myopia prevention and treatment through detailed examination of myopia associated complications and their profound threats to vision.
The Complications of Myopia: A Review and Meta-Analysis
Annechien E G Haarman, Clair A Enthoven, J Willem L Tideman, Milly S Tedja, Virginie J M Verhoeven, Caroline C W Klaver
Purpose: To determine the risk between degree of myopia and myopic macular degeneration (MMD), retinal detachment (RD), cataract, open angle glaucoma (OAG), and blindness.
Methods: A systematic review and meta-analyses of studies published before June 2019 on myopia complications. Odds ratios (OR) per complication and spherical equivalent (SER) degree (low myopia SER < -0.5 to > -3.00 diopter [D]; moderate myopia SER ≤ -3.00 to > -6.00D; high myopia SER ≤ -6.00D) were calculated using fixed and random effects models.
Results: Low, moderate, and high myopia were all associated with increased risks of MMD (OR, 13.57, 95% confidence interval [CI], 6.18-29.79; OR, 72.74, 95% CI, 33.18-159.48; OR, 845.08, 95% CI, 230.05-3104.34, respectively); RD (OR, 3.15, 95% CI, 1.92-5.17; OR, 8.74, 95% CI, 7.28-10.50; OR, 12.62, 95% CI, 6.65-23.94, respectively); posterior subcapsular cataract (OR, 1.56, 95% CI, 1.32-1.84; OR, 2.55, 95% CI, 1.98-3.28; OR, 4.55, 95% CI, 2.66-7.75, respectively); nuclear cataract (OR, 1.79, 95% CI, 1.08-2.97; OR, 2.39, 95% CI, 1.03-5.55; OR, 2.87, 95% CI, 1.43-5.73, respectively); and OAG (OR, 1.59, 95% CI, 1.33-1.91; OR, 2.92, 95% CI, 1.89-4.52 for low and moderate/high myopia, respectively). The risk of visual impairment was strongly related to longer axial length, higher myopia degree, and age older than 60 years (OR, 1.71, 95% CI, 1.07-2.74; OR, 5.54, 95% CI, 3.12-9.85; and OR, 87.63, 95% CI, 34.50-222.58 for low, moderate, and high myopia in participants aged >60 years, respectively).
Conclusions: Although high myopia carries the highest risk of complications and visual impairment, low and moderate myopia also have considerable risks. These estimates should alert policy makers and health care professionals to make myopia a priority for prevention and treatment.
Haarman, A. E. G., C. A. Enthoven, J. W. L. Tideman, M. S. Tedja, V. J. M. Verhoeven and C. C. W. Klaver (2020). “The Complications of Myopia: A Review and Meta-Analysis.” Invest Ophthalmol Vis Sci 61(4): 49.