To evaluate foscarnet sodium in treating cytomegalovirus retinitis in patients with AIDS. Twenty-four previously untreated persons with AIDS and cytomegalovirus retinitis who were at low risk for loss of their visual acuity. PATIENTS were randomly assigned to receive either no therapy (delayed treatment, control group) or immediate treatment with intravenous foscarnet at a dose of 60 mg/kg body weight three times a day for 3 weeks (induction regimen) followed by a maintenance regimen of 90 mg/kg once a day. PATIENTS were examined weekly until they reached the primary clinical end point, defined as progression of their retinitis border by 750 microns or the development of a new retinal lesion due to cytomegalovirus. Progression was evaluated using retinal photographs by masked readers. Secondary evaluations included changes in visual acuity, cytomegalovirus shedding in the blood and urine, serum levels of human immunodeficiency virus type 1 (HIV-1) p24 antigen, and total CD4 T lymphocyte counts. The mean time to progression of retinitis was 3.2 weeks in the control group (n = 11) compared with 13.3 weeks in the treatment group (n = 13) (P less than 0.001). Nine of 13 patients in the treatment group had positive blood cultures for cytomegalovirus at entry and all nine cleared their blood of cytomegalovirus by the end of the induction period (P = 0.004) compared with one of six patients in the control group. No reductions in p24 levels were seen in the control patients compared with a reduction of more than 50% in p24 levels for all four patients on treatment for whom follow-up levels were available. The main adverse effects of foscarnet treatment were seizures (2 of 13 patients), hypomagnesemia (9 of 13), hypocalcemia (11 of 13), and elevations in serum creatinine above 176.8 mumol/L (2.0 mg/dL) (3 of 13). The control patients received an average of 0.2 units of blood per week compared with an average of 0.6 units of blood per week for the patients on treatment. The administration of foscarnet decreases the rate of progression of cytomegalovirus retinitis in persons with AIDS. Its judicious use is likely to prevent loss of vision in these patients. In this study, however, there was little change in visual acuity in patients in either the immediate or delayed treatment group because only patients with non-sight-threatening disease were selected.
In proliferative diabetic retinopathy (PDR), vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF) cause blindness by neovascularization and subsequent fibrosis, but their relative contribution to both processes is unknown. We hypothesize that the balance between levels of pro-angiogenic VEGF and pro-fibrotic CTGF regulates angiogenesis, the angio-fibrotic switch, and the resulting fibrosis and scarring. VEGF and CTGF were measured by ELISA in 68 vitreous samples of patients with proliferative DR (PDR, N = 32), macular hole (N = 13) or macular pucker (N = 23) and were related to clinical data, including degree of intra-ocular neovascularization and fibrosis. In addition, clinical cases of PDR (n = 4) were studied before and after pan-retinal photocoagulation and intra-vitreal injections with bevacizumab, an antibody against VEGF. Neovascularization and fibrosis in various degrees occurred almost exclusively in PDR patients. In PDR patients, vitreous CTGF levels were significantly associated with degree of fibrosis and with VEGF levels, but not with neovascularization, whereas VEGF levels were associated only with neovascularization. The ratio of CTGF and VEGF was the strongest predictor of degree of fibrosis. As predicted by these findings, patients with PDR demonstrated a temporary increase in intra-ocular fibrosis after anti-VEGF treatment or laser treatment. CTGF is primarily a pro-fibrotic factor in the eye, and a shift in the balance between CTGF and VEGF is associated with the switch from angiogenesis to fibrosis in proliferative retinopathy.
18 August 2021 in Ocular Immunology and Inflammation
The COVID-19 pandemic has galvanized the development of new vaccines at an unprecedented pace. Since the widespread implementation of vaccination campaigns, reports of ocular adverse effects after ...