Laser Photocoagulation in Retinal Vein Occlusion

Abstract

Retinal vein occlusion (RVO) is the second most common retinal vascular disease after diabetic retinopathy which is a frequently devastating cause of blindness in mainly in older patients over 60 years of age. Its prevalence changes according to studies in overall populations are from 5.2 to 16 per 1,000 [1][2][3][4] . People with end-organ damage caused by diabetes mellitus and hypertension have strongly increased risk for RVO. The majority of individual diagnosed with RVO defined more than one component of the systemic vascular and metabolic disease, such as the presence of Diabetes Mellitus, hyper tension and high serum lipids. Coexisting metabolic diseases are important factors for prognosis and laser treatment response [1][2][3][4][5] .There are mainly two types of RVO according to occlusion side branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). In BRVO occlusion is located in the any branch of the retinal vein system, while occlusion located exactly in the central retinal vein in CRVO. Different researches shows that BRVO is 4-6 times more common than CRVO and it has been estimated that there are around 80 new cases of CRVO/million population/ year. Although CRVO most commonly affects one eye, in around 10% of patients the disease affects both eyes [2][3][4][5][6][7] . Even RVO was first recognized over a century ago, the exact pathogenesis is not completely nderstood and therefore exact treatment methods not found yet. The condition may be due to a combination of three systemic changes known as Virchow's triad: (1) hemodynamic changes such as venous stasis; (2) degenerative changes of the vessel wall; and (3) blood hypercoagulability [6,8,9] . According to clinical findings, fundus appearance, Fluorescein angiography and electrophisiological results Hayreh futher divided RVO into three types: (1) BRVO is divided further into major BRVO (a) and macular BRVO (b) according to localization; (2) CRVO is divided into ischemic and non-ischemic types due to presence or absence of ABSTRACTVisual acuity is primarily decreased secondary to macular edema, retinal ischemia and complications of neovascularisation in both BRVO and CRVO. Panretinal Laser photocoagulation or Focal photocoagulation is an effecting treatment for neovascularisation and prevention of complications of neovascularisation by ablating ischemic retina in either BRVO or CRVO. But Macular Laser photocoagulation can be use for treatment of non ischaemic macular oedema in only BRVO either alone or combination with other Anti-VEGF or Anti-inflammatory medication.

Efficacy and Safety of Laser Therapy on Ischemic Central Retinal Vein Occlusion: A Systematic Review and Analysis of Clinical Studies

“…Within the therapeutic spectrum, laser therapy has been a cornerstone in managing both ischemic and nonischemic CRVO, primarily through procedures such as laser photocoagulation aimed at reducing macular edema and preventing neovascularisation. Despite its utility, the efficacy of laser photocoagulation in improving visual acuity in CRVO has been limited, contrasting its more pronounced benefits in cases of branch retinal vein occlusion (BRVO) [5,6]. The advent of pharmacological interventions, notably anti-VEGF agents, has heralded a paradigm shift in treatment approaches, offering new avenues for addressing the underlying pathophysiological mechanisms of CRVO [7][8][9].…”