Optic Nerve Head Optical Coherence Tomography Angiography Findings after Coronavirus Disease

Purpose: To quantify the microvasculature density of the optic nerve head (ONH) using optical coherence tomography angiography (OCTA) analysis in patients recovered from Coronavirus Disease 2019 (COVID-19). Methods: In a comparative cross-sectional, observational study, patients recovered from COVID- 19 whose initial diagnosis was confirmed by an rRT-PCR of a nasopharyngeal sample were included in this study. OCTA of ONH was performed in included patients and normal controls. Vascular density (VD) of the all vessels (AV) and small vessels (SV) inside the disc and radial peripapillary capillary (RPC) network density was measured in COVID-19 recovered patients and compared with similar parameters in an age-matched group of normal controls. Results: Twenty-five COVID-19 patients and twenty-two age-matched normal controls were enrolled in the study and one eye per participant was evaluated. The mean whole image SV VD in the COVID-19 group (49.31 ± 1.93) was not statistically significantly different from that in the control group (49.94 ±. 2.22; P = 0.308). A decrease in RPC VD was found in all AV and SV VD measured, which became statistically significant in whole peripapillary SV VD, peripapillary inferior nasal SV VD, peripapillary inferior temporal SV VD, peripapillary superior nasal SV VD, and grid-based AV VD inferior sector (P < 0.05). Inside disc SV VD in the COVID-19 group (49.43 ± 4.96) was higher than in the control group (45.46 ± 6.22) which was statistically significant (P = 0.021). Conclusion: Unremarkable decrease was found in ONH microvasculature in patients who had recovered from COVID-19. These patients may be at risk of ONH vascular complications. Increase in inner disc SV VD may be an indicator of ONH hyperemia and edema

Branch Retinal Artery Occlusion in a Patient with Patent Foramen Ovale

Purpose: To report branch retinal artery occlusion (BRAO) in a patient with patent foramen ovale (PFO). Case Report: A 29-year-old female patient was referred for sudden onset superior visual field defect in her left eye. Ocular examination revealed visual acuity of 20/32 in the affected eye along with a positive relative afferent pupillary defect. A calcified white embolus was noted at the first bifurcation of the inferior temporal artery in her left eye together with mild retinal edema. With a diagnosis of BRAO, the patient received oral acetazolamide, topical timolol, ocular massage and anterior chamber paracentesis. The visual field defect partially recovered and the embolus moved to the third bifurcation level as revealed by fundus examination. An extensive workup, including neurology, rheumatology, cardiology and hematology consultation, carotid ultrasonography, transthoracic/transesophageal echocardiography and laboratory testing was performed. All results were within normal limits except for a small-sized PFO detected by transesophageal echocardiography. Low-dose aspirin therapy was initiated and over the subsequent two years, no other embolic event occurred. Conclusion: The association between PFO and BRAO has not yet been reported. Intracardiac right-to-left shunting through a PFO, accentuated by Valsalva maneuver, may predispose to embolic events while the source of initial thrombosis remains unknown

Photocatalytic Dye Decomposition over CaMnO_3−δ and Pr_0.5Ca_0.5MnO₃: A Combined XPS and DFT Study

In the field of environmental sustainability, the development of highly efficient photocatalytic under a wide wavelength range with band engineering is regarded as a promising strategy to enhance photocatalytic dye degradation. Here, we report on CaMnO3−δ and Pr0.5Ca0.5MnO3 perovskite materials prepared by a sol-gel combustion method. From X-ray photoelectron spectroscopy (XPS), the particle surfaces of both compounds are oxygen deficient, while the surface hydroxyl and carbonyl groups’ adsorption on the surface of Pr0.5Ca0.5MnO3 particles is more pronounced. FT-FIR spectroscopy has been used to investigate the covalent bonds and oxygen vacancy characteristics. Photocatalytic activities were investigated by the degradation of methylene blue and methyl orange under UV light. It was observed that both dye molecules are more degraded over CaMnO3−δ. The underlying mechanisms behind the photoexcitation and degradation process are established via the Spin-polarized Density Functional Theory (DFT)

Sulfur Mustard Exposure and Non-Ischemic Central Retinal Vein Occlusion

A 41-year-old man was referred with a complaint of visual loss in his left eye and his best corrected visual acuity was 20/80. Slit lamp examination showed arborizing conjunctival vessels and dry eye. Fundus examination and fluorescein angiography revealed a non-ischemic central retinal vein occlusion. Cardiovascular, rheumatologic, and hematologic work up showed no abnormal findings. An ascertained history of exposure to sulfur mustard during the Iran-Iraq war was documented in his medical history. Four sessions of intravitreal bevacizumab injections were done as needed. After two-year follow-up, visual acuity in his left eye improved to 20/25 and macular edema was resolved without any need for further interventions. We conclude that sulfur mustard gas exposure may be considered as a predisposing factor for central retinal vein occlusion, as was found in our patient (an Iranian war veteran) by excluding all yet known etiologies and predisposing factors

Photocatalytic Dye Decomposition over CaMnO3−δ and Pr0.5Ca0.5MnO3: A Combined XPS and DFT Study

In the field of environmental sustainability, the development of highly efficient photocatalytic under a wide wavelength range with band engineering is regarded as a promising strategy to enhance photocatalytic dye degradation. Here, we report on CaMnO3−δ and Pr0.5Ca0.5MnO3 perovskite materials prepared by a sol-gel combustion method. From X-ray photoelectron spectroscopy (XPS), the particle surfaces of both compounds are oxygen deficient, while the surface hydroxyl and carbonyl groups’ adsorption on the surface of Pr0.5Ca0.5MnO3 particles is more pronounced. FT-FIR spectroscopy has been used to investigate the covalent bonds and oxygen vacancy characteristics. Photocatalytic activities were investigated by the degradation of methylene blue and methyl orange under UV light. It was observed that both dye molecules are more degraded over CaMnO3−δ. The underlying mechanisms behind the photoexcitation and degradation process are established via the Spin-polarized Density Functional Theory (DFT)

Trachoma: Past, present and future

AbstractPurposeTo review the background, epidemiology and current management of trachoma in endemic areas and worldwide.MethodsReview of literature.ResultsTrachoma is one of the leading causes of preventable blindness in developing countries. It was reported as one of the seven most neglected tropical diseases that can be prevented via drug administration. Its infliction is primarily aimed at those living in areas deprived of clean water and proper sanitation. It is estimated that trachoma is the cause of visual impairment in about 2.2 million people worldwide of which about 1.2 million are completely blind. With implementation of the SAFE (surgery, antibiotics, facial cleanliness, and environmental control) strategy with support from the International Trachoma Initiative (ITI) the incidence of trachoma has decreased significantly in the Middle East and North Africa region.ConclusionWith the enhancement of socioeconomic and sanitary status of people, advent of new generations of antibiotics, training of expert ophthalmologists and eye care facilities the prevalence of trachoma is decreasing

White-to-white corneal diameter:normal values in healthy Iranian population obtained with the Orbscan II

AIM:To determine the normative values of white-to-white corneal diameter with Orbscan II Topography System and to compare right and left eyes data in the normal young population.Methods:A total of 1001 healthy participants aged 18-45y participated in this observational cross-sectional study. The study population consisted of 616 female and 385 male subjects. The corneal diameter was measured with the Orbscan II. The differences between genders, between right and left eyes and age-related changes were evaluated. Statistical analyses were performed using Student’s t-test.RESULTS:The average white-to-white distance in our study population was recorded as 11.65±0.36 mm (median:11.60 mm, mode:11.70 mm, minimum:10.50 mm and maximum:13.60 mm). The white-to-white distance was 11.60±0.35 mm in males and 11.71±0.36 mm in females which was statistically different between genders (P<0.01). However, white-to-white distance was not statistically different between right and left eyes. In addition, this parameter decreased with increasing age. Considering 95% confidence interval, corneal diameter less than 10.93 mm and greater than 12.34 mm would be considered as microcornea and megalocornea, respectively based on this study population, using the Orbscan II topography.CONCLUSION:Detailed description and analysis of corneal diameter with Orbscan demonstrate that the obtained average value of horizontal white-to-white is higher in male than female and decreases slightly with increasing age. Our data also suggests the cut off values for definition of microcornea and megalocornea, which can be employed with this population

Macular retinal and choroidal thickness profile in patients with thyroid‐associated orbitopathy compared to healthy individuals: A cross‐sectional study

Abstract Background and Aims To evaluate the macular thickness profile and central subfoveal choroidal thickness in patients with thyroid‐associated orbitopathy (TAO) compared to healthy subjects. Methods We used the convenience sampling method and divided all participants into the patients and control groups. Based on the clinical activity score (CAS) in the first examination, the patient group was divided to two subgroups: the patients with CAS < 3 and the patients with CAS ≥ 3. Complete ophthalmologic examinations and optical coherence tomography imaging were performed for all participants. Results The mean ± SD of central choroidal thickness was 277 ± 76.58 microns for the control and 326.07 ± 56.574 micron for the patient group which was statistically significant (p = 0.003). We also found that the parafoveal inner thickness is significantly lower in patients compared to healthy subjects (p = 0.02). A comparison of neuro‐structural data between the two subgroups of patients showed a significant difference in central choroidal thickness (p = 0.05). Conclusion This study showed that central choroidal thickness in patients with CAS ≥ 3 compared to those with CAS < 3 and also in the patient group compared to healthy individuals have a significantly increasing trend