Looking Ahead: Visual and Anatomical Endpoints in Future Trials of Diabetic Macular Ischemia.
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ABSTRACT:
SUBMITTER: Cheung CMG
PROVIDER: S-EPMC8619758 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:In this era of evidence-based medicine, significant progress has been made in the field of pharmacotherapeutics for the management of diabetic macular edema (DME). A. number of landmark clinical trials have provided strong evidence of the safety and efficacy of agents such as anti-vascular endothelial growth factors for the treatment of DME. Decades of clinical research, ranging from the early treatment of diabetic retinopathy study to the present-day randomized clinical trials (RCTs) testing novel agents, have shifted the goal of therapy from preventing vision loss to ensuring a maximum visual gain. Systematic study designs have provided robust data with an attempt to optimize the treatment regimens including the choice of the agent and timing of therapy. However, due to a number of challenges in the management of DME with approved agents, further studies are needed. For the purpose of this review, an extensive database search in English language was performed to identify prospective, RCTs testing pharmacological agents for DME. In order to acquaint the reader with the most relevant data from these clinical trials, this review focuses on pharmacological agents that are currently approved or have widespread applications in the management of DME. An update on clinical trials presently underway for DME has also been provided.
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Project description:PurposeVitreous vitamin C, as an anti-oxidant, is responsible for regulating oxygen tension and oxidative stress in the eye. Oxidative stress and retinal ischemia are implicated in the development of proliferative diabetic retinopathy (PDR). In this study, we aimed to determine whether vitreous level of vitamin C is compromised in patients with PDR and to investigate the association of diabetic macular ischemia and vitamin C.MethodsThis prospective study enrolled forty patients who underwent pars plana vitrectomy for the treatment of PDR (PDR group, n = 20) and idiopathic epiretinal membrane (control group, n = 20). Serum, aqueous humor, and the vitreous were collected for the analysis of vitamin C level by HPLC. Diabetic macular ischemia (DMI) in PDR group was evaluated with fluorescein angiography (FA).ResultsPDR patients (60.4 ± 2.1 y) were younger than non-diabetic control patients (67.4 ± 1.2 y). Serum, aqueous, and vitreous levels of vitamin C in PDR were 38.7%, 22.5%, and 11.1% of non-diabetic control group, respectively. All PDR patients had DMI (grade 1: 25%, grade 2: 30%, grade 3: 30%, grade 4: 15%). DMI grade was inversely correlated with the level of vitreous vitamin C (r = -0.546, P = 0.019), not with HbA1C, serum, or aqueous vitamin C level. In addition, the level of vitreous vitamin C (4.5 ± 2.6 μg/ml) in high DMI group (Gr 3 &4) was lower than that (31.0 ± 9.1 μg/ml) in low DMI group (Gr 1&2) (P = 0.015).ConclusionsVitreous level of vitamin C in PDR patients showed a tenfold decrease, which was associated with the degree of macular ischemia. This suggests that vitreous vitamin C depletion may cause macula ischemia in PDR patients.
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Project description:PurposeTo assess different microperimetry (MP) macular sensitivity outcome measures capturing functional deterioration in eyes with geographic atrophy (GA) secondary to age-related macular degeneration (AMD).DesignPatients were included from 2 identically designed, phase III, double-masked, randomized controlled clinical trials, Chroma (NCT02247479) and Spectri (NCT02247531).ParticipantsPatients enrolled were aged ≥ 50 years with bilateral GA and no evidence of previous or active neovascular AMD.MethodsPatients were randomized 2:1:2:1 to receive through 96 weeks intravitreal lampalizumab 10 mg every 4 weeks (LQ4W), every 6 weeks (LQ6W), or corresponding sham procedures. For this study, mesopic macular sensitivity of the central 20° was assessed using MP-1 microperimeter at selected sites.Main outcome measuresTwo exploratory endpoints were developed, namely perilesional sensitivity (average of points adjacent to absolute scotomatous points) and responding sensitivity (average of all nonscotomatous points; > 0 dB at baseline) by using customized masks for each patient. These were compared with conventional MP endpoints (mean macular sensitivity and number of absolute scotomatous points).ResultsOf 1881 Chroma and Spectri participants, 277 agreed to participate in the present study. Of these, 197 (LQ4W, n = 63; LQ6W, n = 68; pooled sham, n = 66) had reliable MP results. Enlargement of GA lesion area by approximately 2 mm2/year across treatment groups was accompanied by deterioration in all MP parameters. There was no difference in worsening of macular sensitivity or absolute scotomatous points among treatment groups. Perilesional and responding sensitivities showed greater decline over time than mean macular sensitivity. Change in GA lesion area at week 48 showed better correlation with perilesional sensitivity (r = -0.17) and responding sensitivity (r = -0.20) than mean macular sensitivity (r = -0.03), while the correlation was highest with the number of absolute scotomatous points (r = 0.37).ConclusionsPerilesional or responding macular sensitivity measured by MP should be considered more sensitive endpoints than mean macular sensitivity for monitoring functional decline over time in GA. Although perilesional, responding, and mean macular sensitivity had weak correlation with GA lesion area, the number of absolute scotomatous points may provide additional information on the anatomic/functional correlation.Financial disclosuresProprietary or commercial disclosure may be found after the references.
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