Rachel Annam

New Treatment Options for Noninfectious Uveitis

Autoimmune uveitis is a group of sight-threatening inflammatory diseases associated with an exacerbated immunological response to ocular proteins. The Standardization of Uveitis Nomenclature Working Group Guidelines have recommended the use of corticosteroids as the first line of therapy for patients who present with active uveitis. However, long-term use of corticosteroids is associated with numerous adverse effects including cataract, glaucoma and metabolic disorders. In this context, new drugs developed to treat rheumatic diseases, and other autoimmune diseases, are being employed often as monotherapy or combined with other immunosuppressive drugs in order to decrease the corticosteroid burden on patients and to manage refractive uveitis. These drugs are currently being evaluated in the framework of uveitis and may open a new horizon with less side effects and more responsiveness for chronic cases. Among others, calcineurin inhibitor voclosporin, mammalian target of rapamycin inhibitor sirolimus, and the IL-1 trap rilonacept, are among these new agents and will be scrutinized in detail in this chapter. More efficient modes of drug delivery are also being employed to deliver high concentration of drug locally and to minimize systemic side effects. The new modes of drug delivery that we will describe in the index chapter include nanoparticles and iontophoresis.

Association of retinal vessel calibre and visual outcome in eyes with diabetic macular oedema treated with ranibizumab.

PurposeThe study aims to identify the association between the baseline retinal vascular calibre and visual outcome of patients with diabetic macular oedema (DMO) treated with intravitreal ranibizumab.MethodsThe 1-M field (as defined in the ETDRS study) of the digital colour fundus photographs of DMO patients who had been treated primarily with ranibizumab in a clinical trial was assessed. Of the 84 patients, 25 had gradable retinal photographs that could be subjected to analyses by the Interactive Vessel Analysis (IVAN) software at baseline. The average retinal vascular calibre of the six largest venules (CRVE) and the six largest arterioles (CRAE) in the peripapillary area (0.5 and 1 disc diameter from the optic disc margin) was measured. The relationship between CRVE and CRAE at baseline and the change in visual acuity at month 12 was assessed using the Mann–Whitney U test.ResultsTen eyes from 10 patients who had shown an improvement of ≥2 lines of best corrected visual acuity (BCVA) at month 12 had a wider baseline CRVE (248.3±24.5 μm) compared with the 15 eyes from 15 patients who did not show the improvement of ≥2 lines (226.6±44.8 μm, P<0.05). The baseline CRAE did not differ significantly in these patients (156.1±22.7 vs 142±17.5 μm, P=0.17).ConclusionsA wider baseline retinal venular calibre may be a predictor of better visual outcome in DMO eyes treated with ranibizumab. Further prospective studies with a larger sample size and a broader range of disease severity and visual acuity are needed to confirm this finding.

Assessment of oxygen saturation in retinal vessels of normal subjects and diabetic patients with and without retinopathy using Flow Oximetry System

PURPOSE To assess oxygen saturation (StO2) in retinal vessels of normal subjects and diabetic patients with and without retinopathy using the modified version of the Flow Oximetry System (FOS) and a novel assessment software. METHODS The FOS and novel assessment software were used to determine StO2 levels in arteries and veins located between 1 and 2 mm from the margin of the optic disc and in the macular area. RESULTS Eighteen normal subjects, 15 diabetics without diabetic retinopathy (DM no DR), and 11 with non-proliferative diabetic retinopathy (NPDR) were included in final analysis. The mean [± standard deviation (SD)] StO2 in retinal arteries was 96.9%±3.8% in normal subjects; 97.4%±3.7% in DM no DR; and 98.4%±2.0% in NPDR. The mean venous StO2 was 57.5%±6.8% in normal subjects; 57.4%±7.5% in DM no DR; and 51.8%±6.8% in NPDR. The mean arterial and venous StO2 across the three groups were not statistically different (P=0.498 and P=0.071, respectively). The arterio-venous differences between the three study groups, however, were found to be statistically significant (P=0.015). Pairwise comparisons have demonstrated significant differences when comparing the A-V difference in the NPDR group to either normal subjects (P=0.02) or diabetic patients without DR (P=0.04). CONCLUSIONS The arterio-venous difference was greater, and statistically significant, in patients with NPDR when compared to normal subjects and to patients with diabetes and no retinopathy. The mean venous StO2 was lower, but not statistically significant, in NPDR compared with diabetics without retinopathy and with normal subjects.

7-Hexagon Multifocal Electroretinography for an Objective Functional Assessment of the Macula in 14 Seconds

Purpose: We present the multifocal electroretinogram (mfERG) with a 7-hexagon array as an objective test of macular function that can be recorded in 14 s. We provide normal values and investigate its reproducibility and validity. Methods: Healthy participants underwent mfERG testing according to International Society for Clinical Electrophysiology of Vision (ISCEV) standards using the Espion Profile/D310 multifocal ERG system (Diagnosys, LLC, Lowell, MA, USA). One standard recording of a 61-hexagon array and 2 repeated recordings of a custom 7-hexagon array were obtained. Results: A total of 13 subjects (mean age 46.9 years) were included. The median response densities were 12.5 nV/deg2 in the center and 5.2 nV/deg2 in the periphery. Intereye correlations were strong in both the center (ρCenter = 0.821; p < 0.0001) and the periphery (ρPeriphery = 0.862; p < 0.0001). Intraeye correlations were even stronger: ρCenter = 0.904 with p < 0.0001 and ρPeriphery = 0.955 with p < 0.0001. Bland-Altman plots demonstrated an acceptable retest mean difference in both the center and periphery, and narrow limits of agreement. We found strong correlations of the center (ρCenter = 0.826; p < 0.0001) and periphery (ρPeriphery = 0.848; p < 0.0001), with recordings obtained by the 61-hexagon method. Conclusions: The 7-hexagon mfERG provides reproducible results in agreement with results obtained according to the ISCEV standard.