Retinal Microvascular Density and Perfusion during an Insulin-Induced Hypoglycemia Episode: A Warning Call.

Aim: To evaluate retinal vascular perfusion and density by optical coherence tomography angiography (OCTA) before, during, and after hypoglycemia in individuals with diabetes mellitus with or without diabetic retinopathy (DR). Methods: A focused clinical history was performed, followed by an ophthalmological examination to document retinopathy status. OCTA was performed at baseline, at hypoglycemia, and at glucose normalization. Eye tracking and eye alignment devices on the platform were used to obtain a macular thickness cube (512 × 128) and vascular perfusion and density protocols of 3 × 3 mm. Retinal vascular reactivity was analyzed with superficial plexus vascular perfusion and density protocols on OCTA. Results: Fifty-two participants encompassing 97 eyes fulfilled the eligibility criteria. Their mean age was 42.9 ± 15.1 years (range, 22 to 65), and 20 (38.2%) were men. We found a statistically significant difference in vascular perfusion and density when comparing all groups at baseline. The controls had higher vascular perfusion and density values than the cases. Vascular perfusion and density were significantly reduced in all groups during the hypoglycemia episode, except for vascular density in DR cases. Conclusion: Acute hypoglycemia significantly alters the retinal vascularity in DM patients with and without DR, suggesting that repeated episodes of acute hypoglycemia could exacerbate retinopathy in the long term.

Use of Evicel Fibrin Sealant in Optic Disc Pit-Associated Macular Detachment.

Optic disc pit is a rare congenital anomaly of the optic nerve. Retinal detachment is a common complication with poor outcomes. Many surgical alternatives have been described for the treatment of this condition, producing variable results. Herein, the authors describe four cases of optic disc pit-associated macular detachment managed with pars plana vitrectomy, fluid-air exchange, drainage of subretinal fluid through the optic disc pit, temporal peripapillary laser, and application of Evicel fibrin sealant (human) (Ethicon, Bridgewater, NJ) over the optic disc head. Case 1 showed stable visual acuity and improvement of subretinal fluid. Cases 2 and 3 showed visual acuity and subretinal fluid improvements. At the 1-week follow-up visit, Case 4 showed almost total subretinal fluid absorption. The sealant invariably disappeared between 1 and 2 weeks and was tolerated by all patients. This case series suggests that Evicel fibrin sealant may be considered as an adjunctive option in the surgical treatment of optic disc pit-associated maculopathy. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:358-363.].

Optical coherence tomography angiography in chorioretinal disorders.

Optical coherence tomography angiography (OCTA) is a novel imaging modality that incorporates blood motion contrast to create angiograms of the retinal vasculature in a noninvasive manner, without the use of dye. It is a safe procedure and can be repeated as frequently as desired. The use of OCTA for delineation of choroidal neovascular membranes, for the study of microvascular abnormalities in diabetic patients, to assess nonperfused areas in retinal occlusions and vascular changes in macular telangiectasia are some of the potential OCTA applications. However, it is not free of drawbacks. Major limitations include the small field of view and its great sensitivity to movement. As a result, it is prone to motion artifacts, leading to poor-quality images. The scope of the body literature regarding this new modality rapidly increases as we learn how to better use this technology. Our objective is to point overall aspects of OCTA, including its limitations and review some of its initial reports on chorioretinal diseases.

Vitreoretinal instruments: vitrectomy cutters, endoillumination and wide-angle viewing systems.

There have been many advances in vitreoretinal surgery since Machemer introduced the concept of pars plana vitrectomy, in 1971. Of particular interest are the changes in the vitrectomy cutters, their fluidics interaction, the wide-angle viewing systems and the evolution of endoillumination through the past decade and notably in the last few years. The indications of 27-gauge surgery have expanded, including more complex cases. Cut rates of up to 16,000 cuts per minute are already available. New probe designs and pump technology have allowed duty cycle performances of near 100% and improved flow control. The smaller vitrectomy diameter can be positioned between narrow spaces, allowing membrane dissection and serving as a multifunctional instrument. Enhanced endoillumination safety can be achieved by changing the light source, adding light filters, increasing the working distance and understanding the potential interactions between light and vital dyes commonly used to stain the retina. Wide-angle viewing systems (contact, non-contact or a combination of both) provide a panoramic view of the retina. Non-contact systems are assistant-independent, while contact systems may be associated with better image resolution. This review will cover some current aspects on vitrectomy procedures, mainly assessing vitrectomy cutters, as well as the importance of endoillumination and the use of wide-angle viewing systems.

Anti-VEGF in a Marathon Runner's Retinopathy Case.

Central retinal vein occlusion (CRVO) is one of the most common retinal vascular disorders. Intense exercise associated CRVO have been described in otherwise healthy young patients. We describe a case of a young male ultramarathoner who presented with a CRVO, presumably associated with dehydration, making part of a marathon runner's retinopathy. Resolution of macular edema and subretinal fluid, with visual acuity improvement, was observed after 3 monthly injections of ranibizumab. Our case suggests that dehydration could be involved in the mechanism of CRVO in healthy young patients and ranibizumab may be an effective treatment option for marathon runner's retinopathy.

Management of optic disk pit-associated macular detachment with tisseel fibrin sealant.

BACKGROUND: Optic disk pit-associated macular detachment is a challenging condition to treat. Many surgical methods have been used to treat this condition with varying degrees of success. METHODS: We managed optic disk pit-associated macular detachment in three cases with pars plana vitrectomy, fluid-air exchange, drainage of subretinal fluid through the optic disk pit, application of Tisseel fibrin sealant (Baxter Healthcare Corporation, CA) to the optic disk pit, C3F8 gas injection, and postoperative prone positioning. RESULTS: All three patients maintained flat maculae and had improved vision. Patient 3 had postoperative macular hole formation. This was managed successfully with pars plana vitrectomy, internal limiting membrane peeling, fluid-air exchange, and C3F8 gas injection. CONCLUSION: Our case series suggest that Tisseel fibrin sealant in conjunction with pars plana vitrectomy can be used successfully for management of optic pit disk-associated macular detachments.