This article is more than 5 years old. Information may no longer be current.
Anti-VEGFs efficacious treatment for myopic choroidal neovascularization
Further studies are needed to better define long-term treatment protocols and identify early markers of CNV.
Click Here to Manage Email Alerts
Anti-VEGF injections for myopic choroidal neovascularization, administered at a much lower frequency than is required for typical age-related macular degeneration, are an effective treatment, according to results of major randomized clinical trials and a comprehensive review of the literature by a panel of experts, published in a new consensus statement on management.
With myopia on the rise among young generations, the prevalence of pathologic myopia and myopic CNV is also expected to increase. The prevalence or myopia is 40% in East Asian countries, but in the U.S. it has reached 24%, and Europe has similar figures, as shown by the Rotterdam Study, Tien Yin Wong, MD, PhD, said.
Pathologic myopia is a possible consequence of high myopia and is estimated to affect about 3% of the global population, typically young people still of working age. If untreated, it leads to severe visual impairment and potentially blindness, with a consequent heavy individual and social burden.
“The only way we can prevent pathologic myopia and myopic CNV is to prevent myopia from developing or progressing. We have learned over these years that the most significant risk factor for myopia is outdoor activities. Children who spend more time outdoor are less likely to become myopic, and this has moved some communities to adopt this as a strategy for prevention. On the other hand, we also have the pharmacological approach with atropine eye drops and a mechanical approach with orthokeratology that suppresses myopic growth,” Wong said.
Diagnosis
The diagnosis of myopic CNV is based on a classic combination of signs and symptoms. Patients report distortion of vision and a central scotoma, usually a black spot in the center of their visual axis. Slit lamp examination shows evidence of hemorrhage and some minimal exudation or edema, not as marked in CNV as in AMD. OCT and fluorescein angiography are currently the gold standard for diagnosis.
“It is not easy to diagnose myopic CNV simply by OCT because the neovascular lesion is smaller than in AMD and in eyes with pathological myopia the OCT images are not as simple to interpret. Some eyes might have staphyloma and therefore an irregular shape, and some of the scans will not properly scan a very long eye,” Wong said.
Therefore, the need for fluorescein angiography is greater for myopic CNV than for AMD, in which OCT now plays a principal role. If there is suspicion of CNV, clinicians should not hesitate to perform fluorescein angiography, Wong recommended.
The new technology of OCT angiography (OCTA) is being tested in myopic CNV, and it is possible that the combination of OCT and OCTA will reduce the need for fluorescein angiography in the future.
“Hopefully we might be able to pick up markers of CNV much better, earlier and in a noninvasive manner. But OCTA is still far from perfect, and most physicians still need [fluorescein angiography] for a proper diagnosis,” he said.
Treatment
Anti-VEGF intravitreal injections have proven to be a highly successful treatment, and myopic CNV is one of the ocular conditions in which anti-VEGF gives the most satisfactory results.
“Most patients respond extremely well and require significantly fewer injections as compared with AMD-related CNV,” Wong said.
In three major studies, MYRROR, REPAIR and RADIANCE, the average number of injections was between two and three in the first year compared with almost seven to nine in the studies on AMD.
“Many patients respond so well that their VA goes back to almost normal if they are diagnosed and treated early,” Wong said.
Most poor responders present late and have a scar formation, or they have a background of pathologic myopia with fundoscopic changes such as multiple areas of atrophy. In these cases, even if the CNV is treated, visual acuity does not improve.
“Both Lucentis (ranibizumab, Genentech) and Eylea (aflibercept, Regeneron) have been tested in randomized clinical trials and are both equally good. We have good experience also using Avastin (bevacizumab, Genentech), but there are no formal trials testing it or comparing it to the other agents, as it was done for AMD,” Wong said.
Wong said that patients should be monitored and treated monthly for the first 3 months. If there is no disease activity and no fluid, the next interval can be extended by 2 weeks and maybe 1 month, and if eyes are stable for several months, they can be seen on a 3- to 4-month basis. If there is no recurrence, the interval can be up to 6 months or 1 year. If visual acuity is stable and the lesion is dry, no injection is needed.
For the small number of patients who do not respond to anti-VEGF treatment, there is no good alternative at the moment, Wong said.
“Steroids and PDT have been tried but have failed to prove effective,” he said.
He said that more research and more trials are needed in this area.
“Companies have concentrated their efforts on mostly AMD and diabetic macular edema and too little attention is given to pathologic myopia. The growing prevalence of this condition, as a consequence of the myopia epidemic, should not find us unprepared,” Wong said. – by Michela Cimberle
- Reference:
- Cheung CMG, et al. Ophthalmology. 2017;doi:10.1016/j.ophtha.2017.04.028.
- For more information:
- Tien Yin Wong, MD, PhD, can be reached at Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751; email: tien_yin_wong@nuhs.edu.sg or ophwty@nus.edu.sg.
Disclosure: Wong reports he is a consultant for Allergan, Bayer and Novartis.