A standardized method to quantitatively analyze optical coherence tomography angiography images of the macular and peripapillary vessels.

BACKGROUND: Optical coherence tomography angiography (OCTA) is a relatively new non-invasive imaging technique to evaluate retinal vascular complexes. However, there is still a lack of standardization and reproducibility of its quantitative evaluation. Furthermore, manual analysis of a large amount of OCTA images makes the process laborious, with greater data variability, and risk of bias. Therefore, the aim of this study is to describe a fast and reproducible quantitative analysis of the foveal avascular zone (FAZ), macular superficial and deep vascular complexes (mSVC and mDVC, respectively), and peripapillary superficial vascular complex (pSVC) in OCTA images. METHODS: We survey models and methods used for studying retinal microvasculature, and software packages used to quantify microvascular networks. These programs have provided researchers with invaluable tools, but we estimate that they have collectively achieved low adoption rates, possibly due to complexity for unfamiliar researchers and nonstandard sets of quantification metrics. To address these existing limitations, we discuss opportunities to improve effectiveness, affordability, and reproducibility of microvascular network quantification with the development of an automated method to analyze the vessels and better serve the current and future needs of microvascular research. OCTA images of the macula (10°x10°, 15°x15°, or 20°x20° centered on the fovea) and peripapillary area (15 × 15º centered on optic nerve head) were exported from the device and processed using the open-source software Fiji. The mSVC, mDVC, and pSVC were automatically analyzed regarding vascular density in the total area and four sectors (superior, inferior, nasal, and temporal). We also analyzed the FAZ regarding its area, perimeter, and circularity in the SVC and DVC images. RESULTS: We developed an automated model and discussed a step by step method to analyze vessel density and FAZ of the macular SVC and DVC, acquired with OCTA using different fields of view. We also developed an automated analysis of the peripapillary SVC. CONCLUSION: Our developed automated analysis of macular and peripapillary OCTA images will allow a fast, reproducible, and precise quantification of SVC, DVC, and FAZ. It would also allow more accurate comparisons between different studies and streamlines the processing of images from multiple patients with a single command.

Complete reversal of bilateral optic nerve infiltration from lymphoblastic leukemia using chemotherapy without adjuvant radiotherapy.

BACKGROUND: Leukemic involvement of the eyes is rare, therefore, treatment relies on previous case reports. The treatment of ocular complications poses additional difficulties, because the eye is considered as a pharmacological "sanctuary" for patients with acute lymphoblastic leukemia (ALL). Therefore, radiotherapy is the main therapeutic choice; however, it might lead to many important side effects. To the best of our knowledge, this is the first case report of a bilateral leukemic optic nerve infiltration that remitted with chemotherapy without adjuvant radiotherapy. CASE PRESENTATION: A 30-year-old female patient with previous history of remitted ALL presented with a one-week history of floaters in her right eye. Her ophthalmological exam showed remarkable optic disc swelling, in both eyes. She was diagnosed with ALL relapse presenting as a bilateral optic nerve leukemic infiltration. Local radiotherapy was planned for both eyes, however, due to efficient recovery with chemotherapy, it was cancelled. Allogenic bone marrow transplantation was subsequently performed. The patient is being followed up and ALL remitted. CONCLUSION: Leukemia relapse on central nervous system, despite rare, is a sign of poor prognosis and requires prompt treatment. Its occurrence on ocular tissues is even rarer. It is hypothesized that the blood-brain barrier limits the delivery of chemotherapeutic drugs to the eye and infiltration of the optic nerve by leukemic cells might prejudice the flow of cerebrospinal fluid between the cranial space and the optic disc.

Safety and cost-effectiveness of single-use endolaser probe reprocessing in vitreoretinal surgery.

BACKGROUND: Endolaser probes have been designed and sold for single-use only. However, in Brazil, they are not included in the list of single-use medical products that are prohibited from being reprocessed and could potentially be reused if safety requirements are accomplished. Therefore, this study aimed to determine and compare the quality, safety and costs of reprocessed versus original single-use endolaser probes of a specific brand and model. METHODS: The study, conducted at a university hospital in Sao Paulo, Brazil, was divided in two phases. The first one tested the feasibility, sterility and physical integrity of ten reprocessed laser probes. In the second phase, all vitrectomy procedures using endolaser probes (reprocessed and original ones) from August 2017 to October 2019 were evaluated. The operated cases were followed for any signs of infection and number of defective probes for each group were counted. The cost of acquiring a new probe and for all reprocessing stages were evaluated and quantified in US dollars($). RESULTS: Microbiologic, residual ethilen oxide and microscopic evaluation of integrity of reprocessed laser probes were all within acceptable range. The second phase of this study included 590 endolaser probes, of which 375 were original and 215 were reprocessed. Functionality rates differed significantly between groups. Among the original probes, 373 (99.47%) were functioning and 2 (0.53%) were non-functioning. Among the reprocessed ones, 201 (93.5%) were functioning and 14 (6.5%) were non-functioning (p < .001). The average cost of one reprocessing was $3.00, and the average cost of an original probe was $150.00. Considering the loss rates, potential savings were $147.60 for each once-reprocessed probe. The frequency of infectious endophthalmitis was null in both groups. CONCLUSIONS: Our study showed that a single cycle endolaser probe reprocessing was safe and efficient, not associated with increase in endophthalmitis rate and proved to be significantly cost-effective, even considering a greater malfunction rate when compared to the original devices.

Optic coherence tomography features of subretinal vitreous substitutes.

BACKGROUND: To draw comparisons between spectral domain optic coherence tomography (SD-OCT) features of subretinal silicon oil (SO), perfluoro-n-octane (PFO) or C3F8 gas. METHODS: Cases diagnosed with retained subretinal vitreous substitutes (VS) were retrospectively selected. Demographic data were collected and OCT features were analyzed. RESULTS: In the 13 cases with subretinal PFO, hyper-reflectivity under the bubble was noted in 8 eyes (61.5%); choroidal shadow at the borders of the bubble in 11 eyes (84.6%); hyper-reflective halo around the bubble in 5 eyes (38.4%) and a hyper-reflective apical dot in 8 eyes (61.5%).The two cases with multiple PFO bubbles had complete septum dividing the bubbles. The one case with subretinal SO had hyper reflectivity under the bubble; no choroidal shadow at the edge of the bubble; hyper-reflective halo was noted around the bubble and the apical hyper-reflective dot was present; there was no complete septum dividing multiple bubbles. The single case with subretinal C3F8 had some bubbles with totally round base, incomplete septum, hyper reflectivity under the bubble, choroidal shadow at the edge of the bubble, a hyper-reflective halo and an apical dot. CONCLUSION: Different subretinal VS share similar SD-OCT characteristics. Round base bubbles are only observed with subretinal C3F8 gas, while incomplete septum are related to retained subretinal SO or gas.