If the individuals on L-DOPA did develop AMD, the age of occurrence of the disease was about eight years later than for those without L-DOPA treatment, and for wet AMD, it was about five years later. At least two further reviews summarize a small “proof of concept” clinical research study by Figueroa et al. in 2021 that evaluated whether individuals who already had wet AMD could receive improvement if they took oral L-DOPA. The summary given by both reviews indicates that oral L-DOPA could cause retinal fluid to decrease by almost 30% even without standard anti-VEGF treatment, and this was accompanied by improvement in visual acuity. In addition, there was about a 50% reduction in the need for anti-VEGF injections. RPE and L-DOPA in amelioration of wet AMD
The retinal pigment epithelium (RPE) (see diagram) has an essential role in the eye. It secretes a large variety of factors including at least 22 proteins important in maintaining the structure, function and micro-environments on the two sides of the RPE. (The two sides of the RPE include the choroid side, where blood vessels form and bring nourishment to the eye, and the photoreceptor side, with rods and cones that receive light signals.) In particular, the RPE secretes vascular endothelial growth factor (VEGF) at its basement membrane, with the VEGF reaching the choriocapillaris to maintain proper blood vessel formation in the choroid region. Many factors, including genetic factors, hypoxia, oxidative stress and inflammatory stressors, may cause pathologic over-production of VEGF by the RPE.
The American Academy of Ophthalmology practice guidelines do not recommend laser coagulation therapy for macular degeneration, but state that it may be useful in people with new blood vessels in the choroid outside of the fovea who dont respond to drug treatment. There is strong evidence that laser coagulation will result in the disappearance of drusen but does not affect choroidal neovascularisation. A 2007 Cochrane review on found that laser photocoagulation of new blood vessels in the choroid outside of the fovea is effective and economical method, but that the benefits are limited for vessels next to or below the fovea.Photodynamic therapy has also been used to treat wet AMD. The drug verteporfin is administered intravenously; light of a certain wavelength is then applied to the abnormal blood vessels. This activates the verteporfin destroying the vessels. Cataract surgery could improve visual outcomes for people with AMD, though there have been concerns about surgery increasing the progression of AMD. A randomized controlled trial found that people who underwent immediate cataract surgery (within two weeks) had improved visual acuity and better quality of life outcomes than those who underwent delayed cataract surgery (6 months).Radiotherapy has been proposed as a treatment for wet AMD but the evidence to support the use of modern stereotactic radiotherapy combined with anti-VEGF is currently uncertain and is awaiting the results of ongoing studies.Nucleoside reverse transcription inhibitors like they are used in anti-HIV therapy was associated with a reduced risk of developing atrophic macular degeneration.