Adaptive optics scanning laser ophthalmoscopy may support early diagnosis of glaucoma.

Purpose: To compare image characteristics of retinal nerve fiber layer (RNFL) between glaucoma patients and healthy controls using adaptive optics scanning laser ophthalmoscopy (AOSLO).

Methods: This was a cross-sectional pilot study with two groups: a glaucoma group with patients with moderate or severe glaucoma as per the Hodapp-Parrish-Anderson classification system and a control group with healthy individuals. The optic nerve damage in moderate glaucoma was predominantly located in only one hemisphere; the other hemisphere was un- or minimally affected on optical coherence tomography and automated perimetry and is referred to as early glaucoma.

A Review on Damage and Rupture Modelling for Soft Tissues.

Computational modelling of damage and rupture of non-connective and connective soft tissues due to pathological and supra-physiological mechanisms is vital in the fundamental understanding of failures. Recent advancements in soft tissue damage models play an essential role in developing artificial tissues, medical devices/implants, and surgical intervention practices. The current article reviews the recently developed damage models and rupture models that considered the microstructure of the tissues.

Thermal Imaging of the Ocular Surface in Thyroid Eye Disease: A Comparison between Active, Inactive and Healthy Eyes.

: To report the temperature differences on the ocular surface using infrared thermal imaging (TI) in thyroid eye disease (TED) and healthy eyes: Prospective, consecutive, comparative case series comparing TI parameters between active and inactive TED with healthy controls. The data captured included baseline demography, activity of TED and the TI parameters. Area under the receiver operating characteristic curves (AUROC) were calculated for the temperature values to determine the sensitivity and specificity in distinguishing active from inactive TED.

Conversion of Flow-restrictive Ahmed Glaucoma Valve to a Nonrestrictive Drainage Implant by Slicing the Valve Leaflets: An In Vitro Study.

Precis: With a newly designed blade, slicing of the Ahmed glaucoma valve (AGV) leaflets helped to convert the flow-restrictive AGV into a non-flow-restrictive device. Flow characteristics by our in-vitro study confirmed the loss of resistance of AGV valve leaflets.

Purpose: To describe a new blade to destroy the valve leaflets of AGV and to report the in-vitro flow characteristics of AGV after valve destruction.

Foveal cone count reduction in resolved endophthalmitis: an adaptive optics scanning laser ophthalmoscopy (AO-SLO)-based prospective pilot study.

Aim: To report the foveal cone count in eyes with resolved endophthalmitis vis-à-vis normal fellow eyes using an indigenous adaptive optics scanning laser ophthalmoscopy (AO-SLO).

Methods: In a prospective cross-sectional comparative pilot study, we recruited patients with resolved endophthalmitis in one eye (study eye) and a normal fellow eye (control eye). Collected data included measurement of the best-corrected visual acuity (BCVA), spectral-domain optical coherence tomography (OCT) imaging and AO-SLO imaging and cone counting at the fovea in both eyes.

Blebophthalmos: proptosis due to a massive bleb following implant surgery in refractory paediatric glaucoma.

A 5-year-old boy with failed combined trabeculotomy and trabeculectomy underwent Ahmed glaucoma valve (AGV) implantation and presented 5 weeks postoperatively, with sudden onset proptosis downward displacement of the globe, limited extraocular movements and displacement of tube from anterior chamber. CT scan of the orbits showed a large cystic bleb with posterior dislocation of the implant and was explanted. In vitro testing of implant for fluid flow characteristics revealed a dysfunctional valve with anterior leak, which could have possibly lead to anterior and inferior fluid accumulation resulting in displacement of implant, a probable cause for this rare complication.

Diagnostic Quality Assessment of Ocular Fundus Photographs: Efficacy of Structure-Preserving ScatNet Features.

Various ophthalmic procedures critically depend on high-quality images. For instance, efficiency of teleophthalmology, a framework to bring advanced eye care to remote regions, is determined by the capability of assessing diagnostic quality of ocular fundus photographs (FPs), and rejecting poor-quality ones at the source. In this context, we study algorithmic methods of classifying high- and low-quality FPs.

Innovative bulls eye drop applicator for self-instillation of eye drops.

Purpose: To report the role of Bulls eye drop applicator device in self-instillation of eye drops and in prevention of wastage of medicine.

Methods: A small pocket sized device "Bulls eye drop applicator" was developed, which is a simple, handy, mirror-based attachment which can be attached to any eye drop bottle to help in accurate self-instillation of the drops in the eye. The prototype of this device was tried in ten volunteer subjects (Group 1) and 15 patients (Group 2); they were asked to use lubricating eye drops (5 ml bottle) in one eye without the device (N) and in the other eye with the device (M).

The Outcomes of a Comprehensive Program for Maintenance of Goldmann Applanation Tonometer.

Precis: We checked 190 tonometers every month and repaired faulty ones. Calibration error (CE) frequency reduced from 23% to 0.6% at 1 year.

Automated 2D-3D quantitative analysis of corneal graft detachment post DSAEK based on AS-OCT images.

Background And Objective: In current ophthalmological practices, assessment of graft condition post Descemet's stripping automated endothelial keratoplasty (DSAEK) is performed qualitatively using few (four) anterior-segment optical coherence tomography (AS-OCT) radial B-scans. From those scans, clinicians need to mentally synthesize the graft in 3D, and estimate its overall condition. In contrast, quantitative representation of 360° thickness profile would facilitate better visualization of graft condition, and hence medical decision making.

Is Ahmed Glaucoma Valve Consistent in Performance?

Purpose: To investigate the mechanism of action and consistency in flow characteristics of the Ahmed glaucoma valve (AGV) under simulated physiological conditions in-vitro and to evaluate whether resistance during priming has any effect on performance of the device.

Methods: Each newly opened AGV device was connected to a digital manometer and was primed with normal saline. The device was then placed in a saline bath and connected to an open manometer, a digital manometer, and an infusion pump.

Author Correction: Quantitative shadow compensated optical coherence tomography of choroidal vasculature.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Quantitative shadow compensated optical coherence tomography of choroidal vasculature.

Conventionally rendered optical coherence tomography (OCT) images of the posterior segment contain shadows which influence the visualization of deep structures such as the choroid. The purpose of this study was to determine whether OCT shadow compensation (SC) alters the appearance of the choroid and the apparent choroidal vascularity index (CVI), an OCT-derived estimated ratio of luminal to total choroidal volume. All scans were shadow compensated using a previously published algorithm, binarized using a novel validated algorithm and extracted binarized choroid to estimate CVI.

Sensitivity of corneal biomechanical and optical behavior to material parameters using design of experiments method.

The optical performance of the human cornea under intraocular pressure (IOP) is the result of complex material properties and their interactions. The measurement of the numerous material parameters that define this material behavior may be key in the refinement of patient-specific models. The goal of this study was to investigate the relative contribution of these parameters to the biomechanical and optical responses of human cornea predicted by a widely accepted anisotropic hyperelastic finite element model, with regional variations in the alignment of fibers.

Automated quantification of Haller's layer in choroid using swept-source optical coherence tomography.

Objective: To develop an algorithm for automated quantification of Haller's layer in choroid using swept-source optical coherence tomography (OCT).

Background: So far, to understand the association of various diseases with structural changes of choroid, only gross indicators such as thickness, volume and vascularity index have been examined. However, certain diseases affect specific sublayers of the choroid.

Semi-automated quantification of hard exudates in colour fundus photographs diagnosed with diabetic retinopathy.

Background: Hard exudates (HEs) are the classical sign of diabetic retinopathy (DR) which is one of the leading causes of blindness, especially in developing countries. Accordingly, disease screening involves examining HEs qualitatively using fundus camera. However, for monitoring the treatment response, quantification of HEs becomes crucial and hence clinicians now seek to measure the area of HEs in the digital colour fundus (CF) photographs.

Investigation of alterations in multifractality in optical coherence tomographic images of in vivo human retina.

Optical coherence tomography (OCT) enables us to monitor alterations in the thickness of the retinal layer as disease progresses in the human retina. However, subtle morphological changes in the retinal layers due to early disease progression often may not lead to detectable alterations in the thickness. OCT images encode depth-dependent backscattered intensity distribution arising due to the depth distributions of the refractive index from tissue microstructures.

Semi-automated quantification of retinal IS/OS damage in en-face OCT image.

A variety of vision ailments are indicated by structural changes in the retinal substructures of the posterior segment of the eye. In particular, integrity of the inner-segment/outer-segment (IS/OS) junction directly relates to the visual acuity. In the en-face optical coherence tomography (OCT) image, IS/OS damage manifests as a dark spot in the foveal region, and its quantification, usually performed by experts, assumes diagnostic significance.

Automated estimation of choroidal thickness distribution and volume based on OCT images of posterior visual section.

A variety of vision ailments are indicated by anomalies in the choroid layer of the posterior visual section. Consequently, choroidal thickness and volume measurements, usually performed by experts based on optical coherence tomography (OCT) images, have assumed diagnostic significance. Now, to save precious expert time, it has become imperative to develop automated methods.

Fundus Photography in the 21st Century--A Review of Recent Technological Advances and Their Implications for Worldwide Healthcare.

Background: The introduction of fundus photography has impacted retinal imaging and retinal screening programs significantly.

Literature Review: Fundus cameras play a vital role in addressing the cause of preventive blindness. More attention is being turned to developing countries, where infrastructure and access to healthcare are limited.

Effect of Intraocular Pressure and Anisotropy on the Optical Properties of the Cornea: A Study Using Polarization Sensitive Optical Coherence Tomography.

Purpose: We hypothesize that because of the anisotropic properties of the cornea, there should be a nonuniform change in birefringence with an increase in intraocular pressure (IOP). In this in vitro study, anisotropic properties, stress distribution within the cornea, and the effect of IOP on changes in stress level were investigated.

Design: Button inflation tests for deformation with polarization sensitive optical coherence tomography were used to demonstrate optical and material anisotropy on ex vivo human corneas.

An automated algorithm for blood vessel count and area measurement in 2-D choroidal scan images.

We present an automated algorithm for the detection of blood vessels in 2-D choroidal scan images followed by a measurement of the area of the vessels. The objective is to identify vessel parameters in the choroidal stroma that are affected by various abnormalities. The algorithm is divided into five stages.