Objective
To quantify the density of the macular microvasculature and the area of the foveal avascular zone (FAZ) in patients recovered from Coronavirus Disease 2019 (COVID-19) using optical coherence tomography angiography (OCTA) analysis.
Methods
In a comparative cross-sectional, observational study, patients recovered from COVID-19 were included in this study. All included subjects exhibited a reverse transcription-polymerase chain reaction (RT-PCR) - confirmed diagnosis of COVID-19. Spectral domain macular OCTA was performed at least 2 weeks after recovery from systemic COVID-19. Vessel density (VD) of the superficial (SCP) and deep retinal capillary plexus (DCP) and the area of the FAZ were measured in COVID-19 recovered patients versus age-matched normal controls.
Results
Thirty-one recovered COVID-19 patients and 23 healthy normal controls were studied. Mean quality scan index was 7.64±0.66 in the COVID cases and 8.34±0.71 in the normal controls (p=0.001). Mean SCP VD and DCP VD of the COVID cohort was significantly lower than the SCP VD and DCP VD of the control group in the foveal and parafoveal regions. FAZ area was greater in the COVID cohort, but this difference was not statistically significant. In addition, in the COVID cohort, VD of the SCP and DCP were lower in patients with a history of COVID-19 hospitalization versus those without such a history but this did not reach statistical significance.
Conclusion
Patients recovered from COVID-19 displayed alterations in the retinal microvasculature including a significantly lower VD in the SCP and DCP. Patients with coronavirus infection may be at risk of retinal vascular complications.
BackgroundClosantel is a halogenated salicylanilide with a potent anti parasitic activity. It is widely used in management of parasitic infestation in animals, but is contraindicated in humans.Case presentationA 34-year-old man with depression was referred to our center with progressive loss of vision in both eyes 10 days after unintentional ingestion of three 500 mg tablets of Closantel. On fundus examination, left optic disc margin was blurred. His bilateral visual acuity was no light perception (NLP) despite prescribed IV erythropoietin injections 20,000 units daily for 3 days and 1gr intravenous methylprednisolone acetate for 3 days followed by 1 mg/kg oral prednisolone. On macular optical coherence tomography (OCT), a disruption in outer retina was observed. Electroretinogram and visual evoked potential tests showed visual pathway involvement.ConclusionsDestruction of neurosensory retina and visual pathways after accidental Closantel use is related to severe visual loss. This case alerts us about the destructive effect of this drug on humans even in low dosage which necessitates preventive efforts to reduce the chance of this morbid side effect.
Highlights
Convalescent plasma (CP) improves outcomes and decrease mortality rate in COVID-19.
CP seems to be most beneficial for treating severe COVID-19 with mild ARDS.
Early administration of CP could contribute to the treatment of severe COVID-19.
Purpose
To compare clinical outcomes between mechanical debridement photorefractive keratectomy (m-PRK) and trans-epithelial photorefractive keratectomy (t-PRK) in myopic patients.
Methods
Eighty eyes of 40 myopic patients with age between 18 and 55 years were included in this study. In each patient, one eye was randomly assigned for t-PRK, using the Amaris laser's ORK-CAM software and the other eye for m-PRK, using a spatula. Stromal ablation was done by Schwind Amaris 750S. Uncorrected and best corrected visual acuity (BCVA), refractive outcomes, epithelial healing, pain, and discomfort were compared between the groups on day 1, 3, 7 and month 1, 3, and 6.
Results
Preoperative spherical equivalent (SE) were −3.97 ± 2.08 diopter (D) and −3.98 ± 2.06 D in m-PRK and t-PRK eyes, respectively (
P
= 0.981). Operation time was significantly shorter in the t-PRK group than m-PRK (
P
< 0.001). Postoperative pain was experienced significantly higher in the t-PRK group measured by 11-point numeric scale of pain questionnaire on the first postoperative day (
P
< 0.001). Photophobia, tearing, and vision fluctuation were also significantly higher in the t-PRK group postoperatively. However epithelial defect size and re-epithelialization time were lower in the t-PRK group (
P
= 0.012 and
P
< 0.001, respectively). Postoperative parameters including SE, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and contrast acuity did not show any significant difference between the two groups during all intervals.
Conclusions
Although epithelial defect size and epithelial healing time were lower in t-PRK, postoperative pain, photophobia, and vision fluctuation were significantly less in the m-PRK group in the first postoperative days. There was no statistically significant difference between the groups after one week, and both mechanical and trans-epithelial techniques were shown to be safe and effective.
The objective of study was to determine the normative values of anterior and posterior best fit sphere (A-BFS and P-BFS) measured with Orbscan II Topography System. In this cross-sectional study, patients (age range: 18-40 years) referred to the Khatam Eye Hospital (Mashhad, Iran) were put in an observational cross-sectional study. The A-BFS and P-BFS were measured with the Orbscan II. The differences between genders, between right and left eyes, and age-related changes were evaluated. A total of 977 healthy participants consisted of 614 female and 363 male subjects aged 18-35 years participated. The average A-BFS in our study population was recorded as 43.060 ± 1.541 D (median: 43.00 D, mode: 43.10 D, range: 38.80-55.80 D). The average P-BFS in our study population was recorded as 52.702 ± 2.190 D (median: 52.60 D, mode: 53.10 D range: 46.9-62.20 D). The A-BFS and P-BFS were respectively 42.753 ± 1.629 and 52.327 ± 2.376 D in males and 43.242 ± 1.457 and 52.924 ± 2.041 D in females, which were statistically different between the genders (P < 0.001). However, A-BFS and P-BFS were not statistically different between right and left eyes (P = 0.649 and P = 0.688 respectively). In addition, A-BFS and P-BFS were not correlated with the age (r = 0.038, P = 0.096 and r = -0.142, P = 0.178 respectively). Considering 95 % confidence interval, A-BFS less than 43.13 D and greater than 42.99 D and P-BFS less than 52.80 D and greater than 52.60 D would be considered abnormal. Detailed description and analysis of A-BFS and P-BFS with Orbscan demonstrated that the obtained average value of BFS were higher in male than female and did not change with increasing age.
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