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Minerva Oftalmologica 2004 March;46(1):55-76

Copyright © 2004 EDIZIONI MINERVA MEDICA

language: Italian

Lasers in ophthalmology

Menchini U., Giansanti F., Virgili G., Giambene B., Cappelli S., Sodi A.

Laser technology in ophthalmology is used to diagnose and treat many ocular diseases. The aim of this paper is to describe the different lasers used in ophthalmology and to report the clinical results of the laser therapy of some ocular diseases such as age related macular degeneration, diabetic retinopathy, retinal vein occlusion, retinal detachment and glaucoma. Therapeutic lasers can be classified in different ways. According to the effect of the laser on the tissue, laser can be classified: a) laser with thermic action; b) laser with mechanical action; c) laser with photochemical-photodynamic action. In the treatment of exudative age-related macular degeneration (AMD), laser photocoagulation and photodynamic therapy (PDT) with verteporfin are supported by randomized-controlled clinical trial, especially for some kind of choroidal neovascularization (CNV). Usually laser photocoagulation is used to treat extrafoveal lesions, while photodynamic therapy is used to treat subfoveal lesions. Laser therapy according to the results of the Early Treatment of Diabetic Retinopathy Study (ETDRS) is effective to prevent and reduce the risk of moderate and severe visual loss (visual acuity reduction of 50% or visual acuity <5/200). The loss of visual acuity depends on the development of a clinical significant macular edema or a high risk proliferative diabetic retinopathy and its consequence as fibrovascular proliferation, vitreous hemorrhage, tractional retinal detachment and neovascular glaucoma. There are different tipes of laser adopted to treat diabetic retinopathy as argon laser, double frequency YAG laser, Krypton and diode laser. Although some experts state that actually there is not any treatment of certain efficacy for the treatment of central retinal vein occlusion (CRVO), there are some information about the laser therapy of CRVO derived from 2 important clinical trials conducted by the Central Vein Study Group. As to branch retinal vein occlusion, photocoagulation is performed to avoid complications of this disease, macular edema and retinal neovascularization. Data obtained from the Collaborative Branch Vein Occlusion Study have allowed to establish present guidelines for photocoagulation. The review of ophthalmologic literature devoted to the prevention of retinal detachment revealed that optimal trials regarding prophylactic treatment are unavailable. Prospective randomized trials of therapy to prevent retinal detachment have not been performed. In the last years diagnostic and therapeutic laser technology showed many improvements for the treatment of glaucoma. Anyway, the most common laser techniques such as iridotomy, trabeculoplasty and gonioplasty, have had few changes since 1980. Recently other techniques such as goniophotoablation, laser selective trabeculoplasty, transcleral and endocyclophotocoagulation, have been introduced in clinical practice, but they are yet under investigation.