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Stimulus deprivation amblyopia (SDA) develops due to an obstruction to the passage of light secondary to a condition such as cataract. The obstruction prevents formation of a clear image on the retina. SDA can be resistant to treatment, leading to poor visual prognosis. SDA probably constitutes less than 3% of all amblyopia cases, although precise estimates of prevalence are unknown. In developed countries, most patients present under the age of one year; in less developed parts of the world patients are likely to be older at the time of presentation. The mainstay of treatment is removal of the cataract and then occlusion of the better-seeing eye, but regimens vary, can be difficult to execute, and traditionally are believed to lead to disappointing results.Our objective was to evaluate the effectiveness of occlusion therapy for SDA in an attempt to establish realistic treatment outcomes. Where data were available, we also planned to examine evidence of any dose response effect and to assess the effect of the duration, severity, and causative factor on the size and direction of the treatment effect.We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to October 2013), EMBASE (January 1980 to October 2013), the Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2013), PubMed (January 1946 to October 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com ), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 28 October 2013.We planned to include randomized and quasi-randomized controlled trials of participants with unilateral SDA with visual acuity worse than 0.2 LogMAR or equivalent. We did not specify any restrictions for inclusion based upon age, gender, ethnicity, co-morbidities, medication use, or the number of participants.Two review authors independently assessed study abstracts identified by the electronic searches.We did not identify any trials that met the inclusion criteria specified in the protocol for this review.We found no evidence on the effectiveness of any treatment for SDA. Future randomized controlled trials are needed in order to evaluate the safety and effectiveness of occlusion, duration of treatment, level of vision that can be realistically achieved, effects of age at onset and magnitude of visual defect, optimum occlusion regimen, and factors associated with satisfactory and unsatisfactory outcomes with the use of various interventions for SDA.

Infestation with Toxoplasma gondii, a parasite, occurs in different body tissues including the eye. It occurs in people throughout the world. The main animal that hosts the organism is the cat, but its principal source is unknown. The parasite is transmitted through ingestion of under-cooked meat and food or drinking water contaminated with cat feces. The disease in the eye has a wide spectrum of presentation, ranging from no symptoms to severe visual impairment. The usual mode of treatment involves administration of anti-parasitic agents. Sometimes corticosteroids are used to supplement anti-parasitic agents with the goal of decreasing the intensity of tissue damage. In this review, we examined evidence on whether using corticosteroids in addition to anti-parasitic agents is more effective than anti-parasitic agents alone. We searched multiple electronic databases for trials evaluating the use of corticosteroids in the management of toxoplasma infestation of the eye. We found no randomized controlled trials to support the use of corticosteroids in addition to anti-parasitic agents for toxoplasma infestation of the eye. Further research is needed and should focus on generating evidence to support regular use of corticosteroids in the management of patients with ocular toxoplasmosis, the dosage, duration of use and time of initiation during the course of anti-parasitic treatment. Outcomes relevant to patients, such as time to recovery from signs and symptoms of visual impairment, should be assessed in future trials addressing this question.

BACKGROUND: Age‐related macular degeneration (AMD) is the most common cause of uncorrectable severe vision loss in people aged 55 years and older in the developed world. Choroidal neovascularization (CNV) secondary to AMD accounts for most cases of AMD‐related severe vision loss. Intravitreous injection of anti‐vascular endothelial growth factor (anti‐VEGF) agents aims to block the growth of abnormal blood vessels in the eye to prevent vision loss and, in some instances, to improve vision. OBJECTIVES: • To investigate ocular and systemic effects of, and quality of life associated with, intravitreous injection of three anti‐VEGF agents (pegaptanib, ranibizumab, and bevacizumab) versus no anti‐VEGF treatment for patients with neovascular AMD • To compare the relative effects of one of these anti‐VEGF agents versus another when administered in comparable dosages and regimens SEARCH METHODS: To identify eligible studies for this review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register (searched January 31, 2018); MEDLINE Ovid (1946 to January 31, 2018); Embase Ovid (1947 to January 31, 2018); the Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to January 31, 2018); the International Standard Randomized Controlled Trials Number (ISRCTN) Registry (www.isrctn.com/editAdvancedSearch ‐ searched January 31, 2018); ClinicalTrials.gov (www.clinicaltrials.gov ‐ searched November 28, 2018); and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en ‐ searched January 31, 2018). We did not impose any date or language restrictions in electronic searches for trials. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that evaluated pegaptanib, ranibizumab, or bevacizumab versus each other or versus a control treatment (e.g. sham treatment, photodynamic therapy), in which participants were followed for at least one year. DATA COLLECTION AND ANALYSIS: Two review authors independently screened records, extracted data, and assessed risks of bias. We contacted trial authors for additional data. We compared outcomes using risk ratios (RRs) or mean differences (MDs). We used the standard methodological procedures expected by Cochrane. MAIN RESULTS: We included 16 RCTs that had enrolled a total of 6347 participants with neovascular AMD (the number of participants per trial ranged from 23 to 1208) and identified one potentially relevant ongoing trial. Six trials compared anti‐VEGF treatment (pegaptanib, ranibizumab, or bevacizumab) versus control, and 10 trials compared bevacizumab versus ranibizumab. Pharmaceutical companies conducted or sponsored four trials but funded none of the studies that evaluated bevacizumab. Researchers conducted these trials at various centers across five continents (North and South America, Europe, Asia, and Australia). The overall certainty of the evidence was moderate to high, and most trials had an overall low risk of bias. All but one trial had been registered prospectively. When compared with those who received control treatment, more participants who received intravitreous injection of any of the three anti‐VEGF agents had gained 15 letters or more of visual acuity (risk ratio [RR] 4.19, 95% confidence interval [CI] 2.32 to 7.55; moderate‐certainty evidence), had lost fewer than 15 letters of visual acuity (RR 1.40, 95% CI 1.27 to 1.55; high‐certainty evidence), and showed mean improvement in visual acuity (mean difference 6.7 letters, 95% CI 4.4 to 9.0 in one pegaptanib trial; mean difference 17.8 letters, 95% CI 16.0 to 19.7 in three ranibizumab trials; moderate‐certainty evidence) after one year of follow‐up. Participants treated with anti‐VEGF agents showed improvement in morphologic outcomes (e.g. size of CNV, central retinal thickness) compared with participants not treated with anti‐VEGF agents (moderate‐certainty evidence). No trial directly compared pegaptanib versus another anti‐VEGF agent and followed participants for one year; however, when compared with control treatments, ranibizumab and bevacizumab each yielded larger improvements in visual acuity outcomes than pegaptanib. Visual acuity outcomes after bevacizumab and ranibizumab were similar when the same RCTs compared the same regimens with respect to gain of 15 or more letters of visual acuity (RR 0.95, 95% CI 0.81 to 1.12; high‐certainty evidence) and loss of fewer than 15 letters of visual acuity (RR 1.00, 95% CI 0.98 to 1.02; high‐certainty evidence); results showed similar mean improvement in visual acuity (mean difference [MD] ‐0.5 letters, 95% CI ‐1.5 to 0.5; high‐certainty evidence) after one year of follow‐up, despite the substantially lower cost of bevacizumab compared with ranibizumab. Reduction in central retinal thickness was less among bevacizumab‐treated participants than among ranibizumab‐treated participants after one year (MD ‐11.6 μm, 95% CI ‐21.6 to ‐1.7; high‐certainty evidence); however, this difference is within the range of measurement error, and we did not interpret it to be clinically meaningful. Ocular inflammation and increased intraocular pressure (IOP) after intravitreal injection were the most frequently reported serious ocular adverse events. Researchers reported endophthalmitis in less than 1% of anti‐VEGF‐treated participants and in no cases among control groups. The occurrence of serious systemic adverse events was comparable across anti‐VEGF‐treated groups and control groups; however, the numbers of events and trial participants may have been insufficient to show a meaningful difference between groups (evidence of low‐ to moderate‐certainty). Investigators rarely measured and reported data on visual function, quality of life, or economic outcomes. AUTHORS' CONCLUSIONS: Results of this review show the effectiveness of anti‐VEGF agents (pegaptanib, ranibizumab, and bevacizumab) in terms of maintaining visual acuity; studies show that ranibizumab and bevacizumab improved visual acuity in some eyes that received these agents and were equally effective. Available information on the adverse effects of each medication does not suggest a higher incidence of potentially vision‐threatening complications with intravitreous injection of anti‐VEGF agents compared with control interventions; however, clinical trial sample sizes were not sufficient to estimate differences in rare safety outcomes. Future Cochrane Reviews should incorporate research evaluating variable dosing regimens of anti‐VEGF agents, effects of long‐term use, use of combination therapies (e.g. anti‐VEGF treatment plus photodynamic therapy), and other methods of delivering these agents.