Eye

No other branch of Surgical subspecialties may experience such dramatic improvements in treatment than that of Ophthalmology (diseases and surgery of the eye).

Age-Related Macular Degeneration

Visudyne is approved in Europe and the USA for the treatment of age related macular degeneration (ARMD) (leaky type) of the eye. age-related macular degeneration (AMD), the most common cause of legal blindness in our maturing Western population [see
“The Challenge of Macular Degeneration,” by Hui Sun and Jeremy Nathans; Scientific American, October 2001]. Most people who acquire AMD have a benign form and do not lose their sight, but about a tenth have a much more aggressive type called wet AMD. In this case, abnormal, leaking blood vessels, like miniature knots of varicose veins, grow underneath the retina and ultimately damage the sharp central vision required forreading and driving. As the disease progresses, central vision is obliterated, making it impossible to recognize people’s faces or the details of objects.

Diabetic Retinopathy

Although a great deal of research and effort has been applied to the condition of ARMD, little research with PDT has been conducted for possible benefits in a similar ‘leaky vessel’ eye condition which could conceivably benefit greatly with PDT; diabetic retinopathy (DR). When a person has diabetes for a number of years fragile and ‘leaky’ small vessels in the retina of the eyes (the lining of the inside of the eye where the light and images of vision are focused) very commonly develop. The leaky protein and hemorrhages associated with diabetic retinopathy in many cases lead to decreases in vision, vitreous hemorrhages (bleeding into the jelly that fills up the eyeball), scarring, retinal detachments, glaucoma (high pressure in the eye) and eventually blindness. The recommended current treatment for many cases of DR is ‘pan-retinal photocoagulation’ or laser burns to large areas of the peripheral retina (areas away from the optic nerve and macula where the central and best vision is present.) Unfortunately, these burns result in a decreased night vision and ‘tunnel’ vision and although clinically has been shown to be helpful in reducing or slowing the cascade of progressively damaging effects on the eye, it is in many people's minds somewhat of a blunt instrument as a therapy. PDT with a photosensitizer which selectively concentrates on the new leaky vessels and with appropriate light therapy delicately closes off and closes the abnormal vessels potentially could represent an elegant, highly selective and effective therapy for DR with few if any significant side effects. It could also well be a more cost-effective and available to the increasing numbers of patients around the world with diabetes and diabetic retinopathy.

view of retina showing leakage and small hemorrhages as well as many yellow dots (laser scars from previous laser treatments-'Pan-retinal Photocoagulation'

Open-Angle Glaucoma (high pressure in the eye) & Cataracts (cloudy lens of the eye)

Neovascularization of cornea, anterior chamber angle, iris and conjunctive (pterygiums)

PDT may also be helpful in 1. clearing the passages in the trabecular meshwork where fluid drains out of the eye 2. clearing early cataracts (the lens of the eye is derived from the same ectodermal layers as the skin), which show huge benefits from PDT for many skin conditions. 3. Eliminating many protozoal infections in the eye that presently need fairly toxic meds to treat 4. Neovascular ingrowths of the cornea, anterior chamber angle iris and conjunctiva. 5. Pterygiums and recurrant pterygiums. 6. various congenital and developmental tumors of the eye. As modern sensitizers are approved a whole new world of therapeutic possibilites will unfold.