[Neurodegenerative biomarkers of the response to diabetic macular edema treatment]

[A modern perspective on the pathogenesis of proliferative diabetic retinopathy]

This article reviews the pathogenic mechanisms underlying proliferative diabetic retinopathy (DR), focusing on the development of angio-fibrotic switch, neurodegeneration, pro-inflammatory and pro-angiogenic biomarkers, emphasizes the modern perspectives on the role of the vitreous body and mechanical traction in DR progression. Understanding of these pathogenic mechanisms will provide new opportunities for improvement and development of treatments for DR at earlier stages, before significant and persistent functional impairment occurs.

Peripapillary retinal nerve fiber layer thickness as a diagnostic tool for pseudophakic cystoid macular edema

PURPOSE

To investigate the effects of pseudophakic cystoid macular edema (PCME) on retinal nerve fiber layer (RNFL) thickness before and after treatment using optical coherence tomography (OCT).

METHODS

A retrospective, observational study of consecutive patients diagnosed with PCME after cataract surgery. Patients underwent macular and RNFL OCT imaging at time of diagnosis and during follow up. OCT was performed for both the study eye and the contralateral healthy eye which served as control. All patients were followed for a period of at least 6 months.

RESULTS

Overall, 40 eyes of 40 patients with a mean age of 71.1 ± 8.1 years of which 45% (n = 18) were of male gender were included in this study. At presentation, the central thickness in the PCME eye was significantly higher than in the contralateral eye (515.7 ± 127.9μm versus 238.1 ± 41.8μm, p < 0.001). Similarly, all macular measurements were significantly higher in the PCME eye compared to the contralateral eye (p < 0.001 for all). In terms of RNFL measurements, the PCME eyes had greater global (p < 0.001), superonasal (p = 0.001) and superotemporal (p = 0.005) thickness values. PCME eyes demonstrated a significant decrease in thickness for all macular and RNFL parameters following resolution of CME (p < 0.05 for all).

CONCLUSIONS

PCME patients presents with greater global, superotemporal and superonasal RNFL thickness in comparison to the other healthy eye. After resolution of PCME, there is significant thinning of RNFL. Peripapillary RNFL thickness may serve as an additional parameter for diagnosis and follow-up of PCME.

[Retinal tomography features of thrombotic microangiopathy associated with atypical hemolytic-uremic syndrome]

OBJECTIVE

To evaluate structural and morphological changes in the retina using optical coherence tomography (OCT) in patients with thrombotic microangiopathy (TMA) associated with atypical hemolytic-uremic syndrome (aHUS).

MATERIAL AND METHODS

The study analyzed OCT data of 14 patients (28 eyes) with an established diagnosis of aHUS including such indicators as central retinal thickness (CRT), thickness of the retinal nerve fiver layer (RNFL), ganglion cell layer (GCL), retinal pigment epithelium (RPE), etc.

RESULTS

Patients with aHUS were noted to have an increase in CRT, paracentral acute middle maculopathy in the form of a hyperreflective defect primarily of the inner nuclear layer of paracentral localization, as well as disorganization of the RPE, which was observed statistically significantly more often compared to healthy persons (p=0.0001, p=0.001 and p=0.009 respectively). In the subgroup with thrombotic retinopathy (6 people) a statistically significant increase in CRT and peripapillary RNFL was found (p=0.004 and p=0.001) compared to patients without thrombotic retinopathy, as well as the presence of paracentral acute middle maculopathy and transudative macular retinoschisis (p=0.0001 and p=0.004). A statistically significant thinning of the peripapillary RNFL was revealed (p=0.0001) in the subgroup with symptoms of Purtscher-like retinopathy (PLR) found retrospectively (4 people) compared to patients without retrospective PLR symptoms. A statistically significant decrease in CRT was revealed (p=0.018) in the subgroup of patients receiving systemic therapy with eculizumab (5 people) compared with patients not receiving this therapy. Statistically significant correlations were recorded between the studied OCT indicators, laboratory indicators, and the level of systolic blood pressure (p<0.05).

CONCLUSION

According to OCT, paracentral acute middle maculopathy is a biomarker of thrombotic retinopathy and the activity of systemic TMA associated with aHUS. Arterial hypertension is an additional aggravating factor in the development of paracentral acute middle maculopathy and transudative macular retinoschisis. Targeted therapy with eculizumab leads to an effective decrease in CRT, which is potentially associated with regression of ischemic edema. The outcome of PLR involves thinning of peripapillary RNFL.

[Anti-VEGF therapy for diabetic retinopathy]

Diabetic retinopathy (DR) is one of the most severe complications of diabetes mellitus, its treatment involves specialists of different areas - endocrinologists, diabetes specialists, therapists, cardiologists, surgeons, anesthesiologists etc. For ophthalmologists the objective is to diagnose ocular pathological changes associated with diabetes mellitus, and to prescribe required treatment in a timely manner. Treatment methods used in DR can be divided into three main groups: laser coagulation of the retina, intravitreal injection of medications - inhibitors of the vascular endothelial growth factor (VEGF) and glucocorticoids, as well as surgical treatment. The present literature review addresses the use of anti-VEGF drugs in the therapy of DR, specifically the latest medications, the most important studies on the treatment of DR and diabetic macular edema (DME), as well as post hoc analysis of such studies, the role of these medications in the therapy of refractory DME and proliferative stage DR. The review also addresses the upcoming strategies for therapy, as well as the importance of medications in prevention of DR and DME.