Disruption of external limiting membrane (ELM) integrity on spectral domain optical coherence tomography (SD-OCT) is associated with lower visual acuity outcomes in patients suffering from diabetic macular edema (DME). However, no automated methods to detect ELM and/or determine its integrity from SD-OCT exist.

Researchers included 16 subjects diagnosed with clinically significant DME (CSME) and these subjects underwent macula-centered SD-OCT (Heidelberg Spectralis, 512 x 19 x 496 voxels). They also scanned 16 subjects without retinal thickening and normal acuity (Carl Zeiss Cirrus, 200 x 200 x 1024 voxels). They achieved automated quantification of ELM disruption as follows. First, 11 surfaces were automatically segmented using their standard 3D graph search approach [18]; the sub-volume between surface six and 11 containing the ELM region was flattened based on the segmented retinal pigment epithelium (RPE) layer; a second, edge-based graph search surface-detection method segmented the ELM region in close proximity "above" the RPE; and each ELM A-scan was classified as disrupted or non-disrupted based on six texture features in the vicinity of the ELM surface. The vessel silhouettes were considered in the disruption classification process to avoid false detections of ELM disruption.

In subjects with CSME, large areas of disrupted ELM are present, the researchers noted. In normal subjects, ELM was largely intact. Additionally, the mean and 95% confidence interval (CI) of the detected disruption area volume for normal and CSME subjects were mean_normal=0.00087 mm³ and CI_normal=(0.00074, 0.00100), mean_CSME=0.00461 mm³ and CI_CSME=(0.00347, 0.00576) mm³, respectively.

In this preliminary study, the study researchers were able to show that automated quantification of ELM disruption is feasible and can differentiate continuous ELM in normal subjects from disrupted ELM in subjects with CSME. They have started determining the relationships of quantitative ELM disruption markers to visual outcome in patients undergoing treatment for CSME.

The authors of this observational cohort study sought to present and evaluate a new method of estimating rates of retinal ganglion cell (RGC) loss in glaucoma by combining structural functional measurements.

The study included 213 eyes of 213 glaucoma patients followed up for an average of 4.5 ± 0.8 years with standard automated perimetry visual fields and optical coherence tomography (OCT). The authors noted that a control group of 33 eyes of 33 glaucoma patients underwent repeated tests over a short period to test the specificity of the method. They used an additional group of 52 eyes from 52 healthy subjects followed up for an average of 4.0 ± 0.7 years to estimate age-related losses of RGCs. They obtained estimates of RGC counts from standard automated perimetry and OCT, and used a weighted average to obtain a final estimate of the number of RGCs for each eye. The study authors calculated the rate of RGC loss for each eye using linear regression. Progression was defined by a statistically significant slope faster than the age-expected loss of RGCs.

From the 213 eyes, 47 (22.1%) showed rates of RGC loss that were faster than the age-expected decline. The authors of the study also reported that a larger proportion of glaucomatous eyes showed progression based on rates of RGC loss rather than based on isolated parameters from standard automated perimetry (8.5%) or OCT (14.6%; p<.01), while maintaining similar specificities in the stable group.

In conclusion, the rate of RGC loss estimated from combining structure and function performed better than either isolated structural or functional measures for detecting progressive glaucomatous damage.

To evaluate the effect of concomitant systemic therapy in patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) treated by intravitreal bevacizumab and to propose a mechanism for different interindividual response, the following retrospective, nonrandomized, single-center, consecutive interventional case series study was performed.

A total of 46 eyes from 46 patients with CNV secondary to AMD were treated by monthly intravitreal 1.25 mg bevacizumab injections on a pro re nata regime. Patients' files were revised and changes in Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), central foveal thickness as determined by spectral domain optical coherence tomography (SD-OCT), number of injections performed, occurrence of severe adverse effects, and systemic concomitant medication were recorded. The effect of systemic medication on final BCVA, central foveal thickness and number of injections performed was evaluated.

It was reported that the most frequent systemic medications recorded were angiotensin-converting-enzyme inhibitors in 19 patients, beta-adrenergic blocking agents (n=18), nonsteroidal anti-inflammatory drugs (n=17), diuretics (n=16), calcium channel blockers (n=14), benzodiazepines (n=11), proton-pump inhibitors (n=9) and statins (n=8). A total of 32 patients had arterial hypertension and average follow-up was 25.1 months (standard deviation [SD]=8.9). Average gain in BCVA was 0.9 (SD=13.6) and –2.1 letters (SD=15.9) at 12 months and 24 months, respectively. It was noted that the average reduction in central foveal thickness was 111 µm (SD=54) and 105 µm (SD=71) at 12 months and 24 months, respectively. The average number of intravitreal injections required was 6.7 (SD=3.2). Furthermore, patients on treatment with systemic beta-adrenergic blocking agents required fewer intravitreal injections (5.2, SD=2.4 vs. 7.9, SD=3.4) and this difference was statistically significant (p=0.0068, multiple linear regression).

It was determined that concomitant systemic beta-adrenergic blocking agents treatment may reduce the need for repeated intravitreal injections of bevacizumab in patients with CNV associated with AMD.