The purpose of this study was to report 5 cases of acute corneal graft rejection after COVID-19 vaccination and perform a review of the literature.Methods: This was a case series and review of literature dated on the October 10, 2021. Results:We describe 5 cases-2 patients with Descemet stripping automated endothelial keratoplasty (for Fuchs endothelial dystrophy) who presented with acute corneal graft rejection after their first dose of mRNA (BNT162) vaccine. The other 3 patients who had penetrating keratoplasty performed more than 10 years ago for keratoconus presented with acute graft rejection-2 patients after their second dose of adenovirus vector (AZD1222) vaccine and 1 patient after first dose of mRNA (BNT162) vaccine. Three patients were not using any topical steroid treatment at the time of diagnosis of graft rejection. The mean duration between vaccination and onset of symptoms was 16.86 6 6.96 days for the mRNA vaccine and 17 6 11.89 days for the adenovirus vector vaccine. Conclusions: Corneal graft rejection has recently been reportedafter COVID-19 vaccination. Patients with keratoplasty need to be advised regarding the risk of corneal graft rejection and warning symptoms of rejection after COVID-19 vaccination. Seeking early referral to the emergency department and increasing topical steroids pre-COVID-19 and post-COVID-19 vaccination may reduce the risk of rejection.

Objectives: To analyze the reproducibility of the new iC100 rebound tonometer, to compare its results with the applanation tonometry and iCare PRO and to evaluate the preference between them. Materials and methods: For the study of reproducibility, 15 eyes of 15 healthy Caucasian subjects were included. Three measurements were taken each day in three separate sessions. For the comparative study, 150 eyes of 150 Caucasian subjects were included (75 normal subjects and 75 patients with glaucoma). Three consecutive measurements were collected with each tonometer, randomizing the order of use. The discomfort caused by each tonometer was evaluated using the visual analogue scale. Results: No statistically significant differences were detected between sessions. In the comparison between tonometers, the measurements with iC100 were statistically lower than those of Perkins (−1.35 ± 0.417, p = 0.004) and that iCare PRO (−1.41 ± 0.417, p = 0.002). The difference between PRO and Perkins was not statistically significant ( p = 0.990). The mean time of measurement (in seconds) with iC100 was significantly lower than with Perkins (6.74 ± 1.46 vs 15.53 ± 2.01, p < 0.001) and that PRO (6.74 ± 1.46 vs 11.53 ± 1.85, p < 0.001). Visual analogue scale score with iC100 was lower than Perkins (1.33 ± 0.99 vs 1.73 ± 1.10, p < 0.05). In total, 61.7% preferred iC100 against Perkins. Conclusion: The reproducibility of this instrument has been proven good. iC100 underestimates intraocular pressure compared to applanation tonometry at normal values and tends to overestimate it in high intraocular pressure values. Most of the subjects preferred iC100 tonometer.

The purpose of this study was to compare corneal topography and densitometry measurements in patients with primary open-angle glaucoma (POAG) and healthy subjects.Patients and Methods: A total of 200 eyes of 75 patients with POAG and 125 healthy controls underwent corneal topography and densitometry (Oculus Pentacam HR). The data compared in the 2 groups were: anterior chamber angle, anterior chamber depth, and anterior chamber volume, keratometry (K minimum , K maximum , and K mean ), central corneal thickness, central anterior elevation, anterior elevation apex, maximum anterior elevation, and posterior elevation apex. Densitometry measurements were made at 3 depths on a 12-mm-diameter circle divided into 4 concentric rings (0 to 2, 2 to 6, 6 to 10, and 10 to 12 mm). The diagnostic capacity of the corneal variables was assessed through the areas under the receiver operating characteristics curve. Results:The corneal density of practically all depth layers and total corneal density were significantly higher in the POAG than the control group (P < 0.05). Total corneal density was positively correlated with age (r = 0.623; P < 0.001) and also showed a good diagnostic capacity for glaucoma [area under the curve = 0.617; 95% confidence interval (CI): 0.541-0.697; P < 0.001]. In a multiple linear regression designed to assess its relationship with age, sex, central corneal thickness, and K mean , age emerged as a significant confounder both in controls (coefficient = 0.315; P < 0.001; 95% CI: 0.246-0.384) and patients (coefficient = 0.370; P < 0.001; 95% CI: 0.255-0.486). Conclusion:Corneal densitometry measurements showed a good diagnostic capacity for POAG suggesting this type of examination could have clinical applications in the diagnosis and management of glaucoma.

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Objective Following nerve injury, the projection of posterior visual pathway lesions into the macular ganglion cell layer (GCL) region indicates retrograde trans-synaptic degeneration (RTSD) as a mechanism of functional damage. Our purpose is to assess GCL damage and the impacts of ischemic brain lesions affecting the visual pathway on macular microvascularization in patients with stroke. Methods In a case-control study, we examined 15 ischemic stroke patients who showed visual field defects and 50 healthy controls using the high-resolution optical coherence tomography (OCT) techniques such as spectral domain-OCT (SD-OCT) to measure retinal nerve fiber layer (RNFL) and GCL thicknesses, and OCT angiography (OCTA) to assess damage to the macular microvasculature. Results In the cases, the correlation was detected among the site of vascular damage, visual field defect, retinal GCL thinning, and normal RNFL thickness. Further observations were significant reductions in macular thickness, GCL thickness, outer retinal layer vascular density, and vascular area in deeper retinal layers (p < 0.05). Conclusion Our findings suggest that ocular microvasculature abnormalities could serve as diagnostic and/or prognostic markers in patients with stroke and support the described use of GCL thickness as an image marker of visual pathway RTSD after brain injury.