Minimum Corneal Diameter and Anterior Steep Axis Curvature Share the Same Meridian: A Novel Finding.

Purpose: To define the external scleral sulcus (ESS) on a Scheimpflug image and use it for a morphometric analysis of corneal diameter (CD).

Design: Retrospective, cross-sectional study of pediatric Asian-Indian eyes.

Methods: One random eye of 353 subjects between 5 and 18 years underwent 25-scan Pentacam HR imaging.

New simulation software to predict postoperative corneal stiffness before laser vision correction.

Purpose: To develop a new virtual surgery simulation platform to predict postoperative corneal stiffness (Kc mean ) after laser vision correction (LVC) surgery.

Setting: Narayana Nethralaya Eye Hospital and Sankara Nethralaya, India; Humanitas Clinical and Research Center, Italy.

Design: Retrospective observational case series.

Inflammation and dry eye disease-where are we?

The presence of inflammation in dry eye disease (DED) results in increased patient symptomatology, ocular surface damage and worsening tear dysfunction. It also affects the health of meibomian glands and their secretions which further aggravates ocular surface disease. This article reviews current knowledge regarding ocular surface inflammation in DED and explores the relationships between the vicious cycles of DED, inflammation and meibomian gland dysfunction (MGD).

COVID-19 positivity rate in corneal tissue donors - A cause for concern!

Purpose: To determine the postmortem positivity for COVID-19 among voluntary eye donors who had been certified to have died of non-COVID-19 causes.

Methods: All donors who donated their corneas (from March 2021 onward) were assessed for COVID-19 positivity tested by nasopharyngeal swab reverse transcription-polymerase chain reaction (RT-PCR) test. Relevant screening history was taken prior to collection.

Surgical technique for the management of corneal perforation in brittle cornea.

Brittle cornea syndrome is among the few special scenarios in ophthalmology that are a nightmare not only for the operating surgeon but also for the patient. Here, the thin and fragile corneas are unable to maintain the shape and structural integrity of the globe and are more prone to minor traumatic or spontaneous corneal perforations. Suturing a brittle cornea and closure of the corneal perforation in a brittle cornea are very challenging requiring the utmost care and special precautions.

Safety and efficacy of combination of suberoylamilide hydroxyamic acid and mitomycin C in reducing pro-fibrotic changes in human corneal epithelial cells.

Corneal haze post refractive surgery is prevented by mitomycin c (MMC) treatment though it can lead to corneal endothelial damage, persistent epithelial defects and necrosis of cells. Suberanilohydroxamic acid (SAHA) however has been proposed to prevent corneal haze without any adverse effects. For clinical application we have investigated the short and long term outcome of cells exposed to SAHA.

Stem cell therapy in coronavirus disease 2019: current evidence and future potential.

The end of 2019 saw the beginning of the coronavirus disease 2019 (COVID-19) pandemic that soared in 2020, affecting 215 countries worldwide, with no signs of abating. In an effort to contain the spread of the disease and treat the infected, researchers are racing against several odds to find an effective solution. The unavailability of timely and affordable or definitive treatment has caused significant morbidity and mortality.

Long-term outcome of custom toric intraocular lens for treating high astigmatism in case of cataract associated with pellucid marginal corneal degeneration.

Pellucid marginal corneal degeneration (PMCD) is a progressive corneal ectasia that ultimately results in high regular astigmatism and correction of this astigmatism is always challenging. However, when a PMCD patient develops a cataract, it provides a golden opportunity to treat this coexisting astigmatism with toric intraocular lens (IOL) implantation. Regular toric IOLs would correct astigmatism only up to 6 diopters in the IOL plane but higher astigmatism would require customization of such IOLs.

Resveratrol Rescues Human Corneal Epithelial Cells Cultured in Hyperosmolar Conditions: Potential for Dry Eye Disease Treatment.

Purpose: Dry eye disease (DED) is a common ocular surface condition across age groups. Recently, vitamin D deficiency has gained importance as a causative factor, and its supplementation alleviates symptoms of DED. Resveratrol (RES) regulates vitamin D receptors (VDRs) and Notch signaling.

Unique corneal tomography features of allergic eye disease identified by OCT imaging and artificial intelligence.

The purpose of this study was to assess unique corneal tomographic parameters of allergic eye disease (AED) using optical coherence tomography (OCT) and artificial intelligence (AI). A total of 57 eyes diagnosed with AED were included. The curvature and aberrations of the air-epithelium (A-E) and epithelium-Bowman's layer (E-B) interfaces were calculated.

Repeatability of OCT Anterior Surface and Bowman's Layer Curvature and Aberrations in Normal and Keratoconic Eyes.

Purpose: To study the repeatability of anterior surface and Bowman's layer curvature in normal and keratoconic eyes using optical coherence tomography (OCT).

Methods: In this study, 96 normal and 96 keratoconic eyes underwent corneal imaging using Pentacam (Oculus Optikgeräte, Wetzlar, Germany) and OCT (Triton, Topcon Corporation, Tokyo, Japan). The elevation data from segmented air-epithelium (A-E) and epithelium-Bowman's layer (E-B) interfaces in OCT scans were used to quantify curvature and aberrations.

Distinct ocular surface soluble factor profile in human corneal dystrophies.

Purpose: Corneal dystrophies (CD) are classified as rare eye diseases that results in visual impairment and requires corneal transplant in advanced stages. Ocular surface inflammatory status in different types of CD remains underexplored. Hence, we studied the levels of tear soluble factors in the tears of patients with various types of corneal dystrophies.

Corneal Viscous Properties Cannot Be Determined From Air-Puff Applanation.

Purpose: To assess whether corneal viscous properties are measureable with air-puff applanation in patients.

Methods: The study had 312 normal eyes, 107 fellow eyes of patients with keratoconus, and 289 keratoconic eyes. The Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) deformation data for all eyes were analyzed using two models.

Temporal Regulation of Notch Signaling and Its Influence on the Differentiation of Cultured Limbal Epithelial Cells.

: Notch signaling plays a vital role in the differentiation and proliferation of corneal epithelial cells from limbal stem cells. The temporal regulation of Notch signaling during this differentiation remains unknown. Hence, we investigated the importance of temporal activation/blockage of Notch signaling during corneal differentiation.

Corneal staining during cataract surgery: Natural course, ASOCT features, and preventive measures.

We report the natural course of the accidental injection of trypan blue into the corneal stroma while performing a routine cataract surgery by a resident during a training session. The corneal staining resolved with conservative medical treatment over 7 weeks. This case describes the anterior segment optical coherence tomography (ASOCT) features of corneal staining.

Characterization of Corneal Epithelial Cells in Keratoconus.

Purpose: We studied the cellular characteristics of epithelial cells in the cone and extraconal periphery of corneas in keratoconus eyes.

Methods: This prospective observational study was conducted at Narayana Nethralaya Eye Institute. A total of 83 and 42 eyes with keratoconus and normal topography, respectively, were included in the study.

Endoilluminator-assisted pediatric cataract surgery with hazy cornea.

The purpose of this study was to demonstrate the usefulness of endoilluminator in pediatric cataract with hazy corneas. We describe a series of three cases of pediatric cataract where visualization of intraocular structures was inadequate under the operating microscope. The endoilluminator was held at the limbus with light directed obliquely to visualize the details of intraocular structures against the hazy cornea using oblique illumination.

Small lens for a big eye: Successful management of anterior megalophthalmos.

We report a case of anterior megalophthalmos and complicated cataract, with apparently smaller lens in both eyes. The right eye had spontaneous retinal detachment. The child underwent cataract surgery in both the eyes with retinal detachment surgery in the right eye.

Waveform analysis of deformation amplitude and deflection amplitude in normal, suspect, and keratoconic eyes.

Purpose: To evaluate the performance of waveform-derived variables in distinguishing normal, suspect, and keratoconic eyes.

Setting: Narayana Nethralaya Eye Hospital, Bangalore, India.

Design: Retrospective case series.

Surgical Outcome of Congenital Cataract in Eyes With Microcornea.

Purpose: To report the intraoperative and postoperative outcomes of congenital cataract surgery in eyes with microcornea.

Methods: In this retrospective, interventional, comparative case series, the authors reviewed 47 eyes of 26 children with microcornea and congenital cataract (21 bilateral and 5 unilateral) who underwent lens aspiration with primary posterior capsulectomy and anterior vitrectomy between 2008 and 2014 with a minimum follow-up period of 6 months. Demographic profiles and systemic and ocular features were documented.

Correlation of Corneal Biomechanical Stiffness With Refractive Error and Ocular Biometry in a Pediatric Population.

Purpose: To assess the correlation between corneal biomechanical stiffness and refractive error (RE) in the pediatric population.

Methods: A total of 733 pediatric eyes were included in the study retrospectively. All eyes underwent corneal tomography (Pentacam), RE assessment, and air-puff deformation (Corvis-ST).

Noncontact Quantification of Topography of Anterior Corneal Surface and Bowman's Layer With High-Speed OCT.

Purpose: To quantify keratometry and wavefront aberration of the anterior corneal surface and epithelium-Bowman's layer interface using anterior segment optical coherence tomography (OCT).

Methods: Twenty-five normal eyes and 25 eyes with keratoconus were retrospectively analyzed. The anterior corneal edge and epithelium-Bowman's layer interface were segmented from 12 distortion-corrected OCT B-scans.

One for all: A standardized protocol for ex vivo culture of limbal, conjunctival and oral mucosal epithelial cells into corneal lineage.

Background Aims: Autologous transplantation of ex vivo cultured cells the treatment of choice for patients with limbal stem cell deficiency. The most commonly used cell sources for transplantation limbal, conjunctival or oral mucosal tissue. Protocols vary for culturing each tissue type, and there are no comparative studies on transplantation outcomes using these different culture techniques.