Corneal confocal microscopic characteristics of acute angle-closure crisis

Background To investigate characteristics of the acute angle-closure crisis (AACC) and fellow eyes using confocal microscopy. Methods Unilateral AACC patients hospitalized at the Xi’an People’s Hospital from October 2017 to October 2020 were recruited in this cross-sectional study. Age-matched participants scheduled for cataract surgery were enrolled as a healthy control group. Corneal epithelial cells, subepithelial nerve fiber plexus, stromal cells, and endothelial cells were examined by confocal and specular microscopy. Results This study enrolled 41 unilateral AACC patients (82 eyes) and 20 healthy controls (40 eyes). Confocal microscopy revealed that the corneal nerve fiber density, corneal nerve branch density and corneal nerve fiber length were reduced significantly in AACC eyes. The stromal cells were swollen and the size of the endothelial cells was uneven with the deposition of punctate high-reflective keratic precipitate on the surface. In severe cases, the cell volume was enlarged, deformed, and fused. The corneal subepithelial nerve fiber, stromal layer, and endothelial layer were unremarkable in the fellow eyes, and the density of the endothelial cells was 2601 ± 529 cells/mm2, which was higher than 1654 ± 999 cells/mm2 in AACC eyes (P < 0.001). Corneal edema prevented the examination of 17 eyes using specular microscopy and in only four eyes using confocal microscopy. There were no significant differences in endothelial cell density between confocal and specular microscopy in the AACC eyes (P = 0.674) and fellow eyes (P = 0.247). The hexagonal cell ratio reduced significantly (P < 0.001), and average cell size and coefficient of variation of the endothelial cells increased significantly compared with fellow eyes (P < 0.001, P = 0.008). Conclusions AACC eye showed decreased density and length of corneal subepithelial nerve fiber plexus, activation of stromal cells, increased endothelial cell polymorphism, and decreased density.

Bilateral laser peripheral iridotomy in a co-occurrence of unilateral iridocorneal endothelial syndrome and chronic angle closure glaucoma

Purpose To report a case of unilateral Iridocorneal endothelial (ICE) syndrome- Progressive iris atrophy (PIA) with an overlapping chronic angle closure glaucoma (CACG) and to highlight the effect of bilateral Laser peripheral iridotomy (LPI) in such a co-occurrence. Case description A patient presented to us with bilateral gradual painless progressive diminution of vision. Both eyes (BE) had a clear cornea, shallow peripheral anterior chamber depth, grade 2 nuclear sclerosis, raised intraocular pressure and glaucomatous optic neuropathy. In addition, the Left eye (LE) had an irregular anterior chamber, peripheral anterior synechiae (PAS) extending to cornea, patchy iris atrophy, subtle corectopia and a low endothelial cell count on specular microscopy. Indentation gonioscopy led to the diagnoses of CACG BE with ICE syndrome- PIA LE. LPI was performed bilaterally. On Anterior Segment Optical Coherence Tomography (ASOCT), there was evident widening of the angle away from PAS in the Right eye as well as in the LE with PIA post LPI. Conclusion This is a unique case of unilateral PIA with an associated CACG in BE. It is the first case demonstrating the effect of bilateral LPI in such a case scenario. Though not indicated in ICE syndrome, LPI did show short term evidence of significant widening of the angle away from areas of PAS even in the eye with PIA having a limited high PAS and a concurrent primary (chronic) angle closure disease.

A Liquid Hydrogel to Restore Long Term Corneal Integrity After Perforating and Non-Perforating Trauma in Feline Eyes

Purpose: To evaluate long-term in vivo functionality of corneas regenerated using a cell-free, liquid hydrogel filler (LiQD Cornea) after deep corneal trauma in the feline model.Methods: Two healthy cats underwent 4 mm diameter stepwise 250/450 µm deep surgical corneal ablation with and without needle perforation. The filler comprising 10% (w/w) collagen-like peptide conjugated to polyethylene glycol (CLP-PEG) and 1% fibrinogen and crosslinked with 2% (w/w) 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM), was applied to the wound bed previously coated with thrombin (250 U/ml). In situ gelation occurred within 5 min, and a temporary tarsorrhaphy was performed. Eyes were examined weekly for 1 month, then monthly over 12 months. Outcome parameters included slit-lamp, Scheimpflug tomography, optical coherence tomography, confocal and specular microscopy, and immunohistochemistry studies.Results: The gelled filler was seamlessly incorporated, supporting smooth corneal re-epithelialization. Progressive in-growth of keratocytes and nerves into the filler corresponding to the mild haze observed faded with time. The regenerated neo-cornea remained stably integrated throughout the 12 months, without swelling, inflammation, infection, neovascularization, or rejection. The surrounding host stroma and endothelium remained normal at all times. Tomography confirmed restoration of a smooth surface curvature.Conclusion: Biointegration of this hydrogel filler allowed stable restoration of corneal shape and transparency in the feline model, with less inflammation and no neovascularization compared to previous reports in the minipig and rabbit models. It offers a promising alternative to cyanoacrylate glue and corneal transplantation for ulcerated and traumatized corneas in human patients.

Effect of Myopic Femtosecond Laser-Assisted LASIK on Anterior Chamber Inflammation (Flare Values) and Corneal Endothelium: A Prospective before and after Study

Purpose. This study aimed to investigate whether femtosecond laser-assisted LASIK (FS-LASIK) surgery causes inflammation in the anterior chamber and to analyze its effect on endothelial cells. Methods. This prospective, longitudinal study included left eyes of 30 patients (19 females) who had undergone FS-LASIK surgery due to myopia and myopic astigmatism. Endothelial cell density (ECD) and morphological measurements were performed using a specular microscopy, and laser flare photometry was used to measure the anterior chamber flare values on the day of surgery. iFS™ Advanced FS and VISX STAR S4-IR Wavescan Excimer Laser platforms were used. Flare measurements were repeated on the postoperative 1st day and 7th day and the 1st and 3rd months. The endothelial measurements were repeated in the 3rd month. Results. Preoperatively, the mean flare was 5.59 ± 1.24 photons/ms; it was 6.49 ± 2.42 on the postoperative 1st day, 5.87 ± 2.27 on the 7th day, 5.68 ± 1.66 on the 1st month, and 5.35 ± 1.24 on the 3rd month. A significant difference was observed only between the preoperative and postoperative 1st day flare values ( p = 0.047 ). The decrease in the ECD was clinically insignificant but statistically significant, with an average of 97.0 ± 209.9 cell count/mm2 (3.3%, p = 0.017 ). However, there was no significant change in the coefficient of variation ( p = 0.448 ) and hexagonality ( p = 0.096 ). No significant correlation was found between the increase in the flare value on the postoperative 1st day and variables. A significant correlation was found between the decrease in ECD and the preoperative ECD (r = 0.356, p = 0.027 ). Conclusion. FS-LASIK caused minimal inflammation in the anterior chamber on only the 1st postoperative day; additionally, a minimal decrease of cell count with no morphological changes were noted in the endothelial cells on postoperative 3rd month. This trial is registered with NCT04899258.

Parry Romberg Syndrome with contralateral iridocorneal endothelial syndrome: a unique case

Parry-Romberg syndrome (PRS) is a rare disorder which causes progressive hemifacial atrophy, with ocular manifestations like hypotony, enophthalmos and corneal edema on the ipsilateral atrophic side. This is a report of a unique case of PRS with contalateral manifestations like ectropion uvea, correctopia and endothelial deposits, along with polymegathism and pleomorphism seen on specular microscopy suggestive of Iridocorneal Endothelial (ICE) Syndrome. ICE syndrome and PRS have not been reported together in any literature so far. This case highlights the importance of a thorough glaucoma workup and corneal examination on the atrophic facial side as well as on the apparently normal side in all cases of PRS.

Correlation between ocular biometric parameters and corneal endothelium in a sample of young Egyptian adults

Background: To evaluate the normative values of corneal endothelial cell parameters within a group of healthy young Egyptian adults using specular microscopy and to examine any correlations between endothelial parameters and refractive or biometric parameters.Methods: In this cross-sectional study, specular microscopy was used to study the right eyes of 150 healthy young volunteers and evaluated endothelial cell parameters, including cellular density, hexagonality (HEX), and coefficient of variation (CV) at 15 different points on the back corneal surface, which were later grouped into the central zone and either four quadrants or three annular zones. The same eyes underwent refractive and biometric assessments.Results: Hundred fifty healthy adults were examined, and the age ranged from 20 to 30 years, with a median of 23 (interquartile range, 21?27) years. The mean ± standard deviation of central cell density was 2902.7 ± 270.7 cells/mm2. The superior paracentral area had the lowest mean density (2895.8 cells/mm2), but the highest mean HEX (67.7%), while the inferior peripheral area had the highest mean density (3100.5 cells/ mm2) but the lowest mean HEX (64%). The difference in cell density among the three annular zones was not statistically significant (P = 0.365). However, HEX and CV in the central and paracentral zones differed statistically significantly from those of the peripheral zone (P < 0.001 and P = 0.014, respectively). Weak but non-significant correlations were detected between endothelial cell density and all measured refractive and biometric parameters.Conclusions: The findings of this study provided useful normative biometric and specular data in a specific age group and a specific population, and could be useful in planning intraocular surgery in young Egyptian adults. However, future longitudinal studies with a larger sample could refine more endothelial cell parameter specifications over time.

Protocol to test the efficacy and safety of frequent applications of skin electrical stimulation for Leber hereditary optic neuropathy: a single-arm, open-label, non-randomised prospective study

IntroductionLeber hereditary optic neuropathy (LHON) is an acute or subacute inherited optic neuropathy caused by mitochondrial mutations. More than 90% of patients with LHON have one of three point mutations (ie, G3460A, G11778A and T14484C). We previously reported that a 12-week session of skin electrical stimulation (SES) with a 2-week interval significantly improved visual acuity and field tests 1 week after the last stimulation and without adverse effects in 10 cases of LHON carrying the mt DNA G11778A mutation. In the present study, we will examine the magnitude and persistence of the efficacy and presence or absence of adverse events using SES with a more frequent stimulation protocol.Methods and analysisThis study will be a single-arm, open-labelled, non-randomised clinical study that analyses 15 cases of LHON with G11778A mutation. All participants will take a portable SES device home and perform SES by themselves every other day for 12 weeks. The logarithm for the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) at 1 week after the last SES will be measured as the primary outcome. LogMAR BCVA will be measured at four and 8 weeks after the last SES treatment. The Humphrey visual field sensitivity test using size V stimulation and critical fusion frequency at 1, 4 and 8 weeks after the last SES session will be secondary outcome measurements. Slit-lamp examination, optical coherence tomography and specular microscopy will also be performed to verify the safety of SES.Ethics and disseminationThe protocol was approved by the Institutional Review Board at Kobe University, Japan (Approval No.C190030). This study is in progress and deserves Pre-result. All documents communicating with the ethics committee will be reposited by the researcher. Modifications to the protocol will be reviewed by the ethics committee and implemented after approval. Data monitoring will be performed by a researcher who is not involved in the study every 6 months after approval. The research summary results will be registered in the Japan Registry of Clinical Trials (jRCTs) and made available to participants in accordance with the terms described in the documents. In addition, the results of this study will be presented at domestic and international meetings and published in peer-reviewed journals within a year after data is fixed.Trial registration numberjRCTs052200033.