Three-year Outcomes of an Expanded Asynchronous Virtual Glaucoma Clinic in Singapore.

PURPOSE: Virtual glaucoma clinics can help increase health care capacity, easing the disease burden of glaucoma. This study assesses the safety, rate of glaucoma progression, time efficiency, and cost-savings of our expanded Glaucoma Observation Clinic (GLOC) at the Singapore National Eye Centre over 3 years. METHODS: All patients seen at GLOC between July 2018 and June 2021 were included. Visual acuity, intraocular pressure, and visual fields or optic nerve head imaging were recorded, followed by a virtual review of the data by an ophthalmologist. An objective review of the management of 100 patients was conducted by 2 senior consultants independently as a safety audit. Patient outcomes including the rate of instability (due to worsening of clinical parameters necessitating a conventional clinic visit), glaucoma progression, the consultation review time efficiency, and cost-savings of GLOC were measured. RESULTS: Of 3458 patients, 16% had glaucoma, and the others had risk factors for glaucoma. The safety audit demonstrated a 95% interobserver agreement. The rate of instability was 14.6%, of which true progression was observed in 3.12%. The time taken for a glaucoma specialist to review a GLOC patient was 5.75±0.75 minutes compared with 13.7±2.3 minutes in a conventional clinic. The per capita manpower cost per GLOC patient per visit was $36.77 compared with $65.62 in the conventional clinic. This translates to a cost-saving of $280.65 over the lifetime of a hypothetical patient. CONCLUSIONS: Our expanded virtual glaucoma clinic is a safe, time-efficient, and cost-effective model with low rates of glaucoma progression, which could allow for significant health care capacity expansion.

Effect of peripheral iridectomy on VEGF-A and TGF-ß levels in rabbit aqueous humour.

BACKGROUND: Peripheral iridectomy (PI), routinely performed during glaucoma filtration surgery, may contribute to scarring. This study aims to determine whether PI alters the concentrations of VEGF-A and TGF-ß isoforms in the rabbit aqueous humour. METHODS: Anterior chamber paracentesis (ACP) was performed in both eyes of six New Zealand white rabbits, with additional surgical PI performed in the right eyes. Eyes were examined on postoperative days (PODs) 1, 7, 30 and 60 by means of the tonopen, slit-lamp biomicroscopy, and bead-based cytokine assays for TGF-ß and VEGF-A concentrations in the aqueous humor. RESULTS: ACP caused a significant reduction in intraocular pressure (IOP) from mean preoperative 11.47 ± 1.01 mmHg to 5.67 ± 1.63 mmHg on POD 1 while PI did not cause further IOP reduction. Limbal conjunctival vasculature appeared slightly increased on POD 1 in both ACP and PI eyes with PI also causing mild bleeding from damaged iris vessels. Two PI eyes developed fibrinous anterior chamber reaction and/ or peripheral anterior synechiae. Aqueous VEGF-A levels were not significantly different between eyes treated with ACP and PI. Aqueous TGF-ß concentrations distributed in the ratio of 4:800:1 for TGF-ß1:TGF-ß2:TGF-ß3 respectively. While aqueous TGF-ß2 was not significantly induced by either procedure at any time point, TGF-ß1 and TGF-ß3 were significantly induced above baseline levels by PI on POD 1. CONCLUSION: PI increases the risk of inflammation. The combined induction of aqueous TGF-ß1 and TGF-ß3 by PI in glaucoma surgery may impact surgery success in glaucoma subtypes sensitive to these isoforms.

Outcomes of surgical bleb revision at a tertiary Singapore eye hospital.

PURPOSE: To describe the outcomes of surgical bleb revisions from a tertiary glaucoma service in Singapore. METHODS: One hundred and thirty-one eyes of 129 patients who underwent surgical bleb revisions at the Singapore National Eye Centre between 2007 and 2014 were included in the study. The indications for bleb revision were: bleb-related infection (BRI), early and late bleb leak, early and late overfiltration, and bleb dysesthesia. Regression analysis was applied to elucidate risk factors. RESULTS: The mean age of the patients was 66 years, 62.6% were male, and 88.5% were Chinese. The majority of the eyes had primary glaucoma (79.4%). The mean interval from the initial trabeculectomy or phaco-trabeculectomy to the bleb revision was 58.8 months. The overall success rate was 69.5%. By Kaplan-Meier survival analysis, the overall cumulative success range fell from 78.6% to 49.1% over 10 years. Eyes with early bleb leak had lower surgical success compared to eyes with late bleb leak, early overfiltration and late overfiltration (P = 0.026, log-rank test). The IOP improved significantly post-operatively for eyes with BRI, early bleb leak, late bleb leak, early overfiltration and overfiltration (P < 0.05). Vision improved significantly in eyes with early overfiltration, but deteriorated in eyes with BRI (P < 0.05). CONCLUSION: The overall success rate for surgical bleb revisions was good with complete resolution of the primary problem in the majority of cases. However, eyes with early bleb leak were less likely to have successful outcomes and should be monitored more closely post-operatively.

New digital models of care in ophthalmology, during and beyond the COVID-19 pandemic.

COVID-19 has led to massive disruptions in societal, economic and healthcare systems globally. While COVID-19 has sparked a surge and expansion of new digital business models in different industries, healthcare has been slower to adapt to digital solutions. The majority of ophthalmology clinical practices are still operating through a traditional model of 'brick-and-mortar' facilities and 'face-to-face' patient-physician interaction. In the current climate of COVID-19, there is a need to fuel implementation of digital health models for ophthalmology. In this article, we highlight the current limitations in traditional clinical models as we confront COVID-19, review the current lack of digital initiatives in ophthalmology sphere despite the presence of COVID-19, propose new digital models of care for ophthalmology and discuss potential barriers that need to be considered for sustainable transformation to take place.

Outcomes of an Asynchronous Virtual Glaucoma Clinic in Monitoring Patients at Low Risk of Glaucoma Progression in Singapore.

PURPOSE: To assess the implementation outcomes of a new asynchronous virtual clinic, the Glaucoma Observation Clinic (GLOC), at the Singapore National Eye Center, in monitoring patients at low risk for glaucoma progression. METHODS: Patients with low risk of glaucoma progression were followed up at GLOC. Visual acuity, intraocular pressure, and visual field testing or optic nerve head imaging were assessed by nurses and technicians, with virtual review of data by an ophthalmologist separately. The implementation outcomes were defined as patient satisfaction, assessed by a nurse-administered questionnaire; the rate of referrals back to the glaucoma outpatient department; the patients' journey time (minutes); the time taken for the specialist review (minutes), and the per capita manpower cost compared with current glaucoma outpatient model. RESULTS: A total of 377 patients were included, with the majority being glaucoma disc suspects (n = 250, 66.4%) and primary angle closure suspects (n = 54, 14.3%). Most patients (more than 90%) reported being satisfied, and only 7.7% (n = 29) were referred back to the specialist outpatient glaucoma clinic due to possible glaucoma progression. Compared with the glaucoma outpatient clinic, the average journey time in GLOC was 50% less (59.3 mins vs 132 mins), the average time for a specialist review was 3 times faster (5.8 mins vs 19.5 mins), and the per capita manpower cost of GLOC was halved ($20.07 vs $39.78). CONCLUSIONS: GLOC is a time-efficient, cost-saving, and sustainable model of care for managing patients with low risk of glaucoma progression. It was well received by patients and freed up the conventional clinic to treat patients with complex needs.

Integration of Genetic and Biometric Risk Factors for Detection of Primary Angle Closure Glaucoma.

PURPOSE: The purpose of this study was to investigate whether the addition of primary angle closure glaucoma (PACG)-associated genetic loci allows improved detection of PACG, compared to anterior segment parameters measured by imaging. DESIGN: Case-control study. METHODS: Genotype data of the 8 PACG single-nucleotide polymorphisms (SNPs) (rs11024102 at PLEKHA7, rs3753841 at COL11A1, rs1015213 located between PCMTD1 and ST18 on Chromosome 8q, rs3816415 at EPDR1, rs1258267 at CHAT, rs736893 at GLIS3, rs7494379 at FERMT2, and rs3739821 mapping in between DPM2 and FAM102A) were available. Customized software was used to measure anterior segment optical coherence tomography (ASOCT) parameters, namely, anterior chamber depth, width, and area (ACD, ACW, and ACA) and lens vault (LV). Statistical analysis for positive predictive values was modeled using the receiver operating characteristic curve (AUC). Statistical significance comparing predictive power of the different parameters was calculated using permutation. RESULTS: A total of 388 PACG subjects and 751 controls with both ASOCT and genetic data were available for analysis. Anterior segment parameters including ACD, ACA, and LV had excellent predictive value (AUCs >0.94), except ACW (AUC=0.65), for identifying PACG. The inclusion of genetic risk alleles (either singly or as a composite genetic risk score for 8 genomewide association study SNPs) to ACD only provided a +0.50% improvement in reclassifying PACG cases and controls over and above the discriminatory value of ACD. This +0.50% improvement was not statistically significant (P > .05). CONCLUSIONS: Although significant on their own, the incorporation of genetic data in the context of anterior segment imaging parameters like ACD provided only a marginal improvement of PACG detection.

Sequential Doping Reveals the Importance of Amorphous Chain Rigidity in Charge Transport of Semi-Crystalline Polymers.

Sequential doping is a promising new doping technique for semicrystalline polymers that has been shown to produce doped films with higher conductivity and more uniform morphology than conventional doping processes, and where the dopant placement in the film can be controlled. As a relatively new technique, however, much work is needed to understand the resulting polymer-dopant interactions upon sequential doping. A combination of infrared spectroscopy and theoretical simulations shows that the dopants selectively placed in the amorphous regions in the film via sequential doping result in highly localized polarons. We find that the presence of dopants within the amorphous regions of the film leads to an increase in conjugation length of the amorphous chains upon doping, increasing film connectivity and hence improving the overall conductivity of the film compared with the conventional doping processes.

A Rabbit Model Study to Determine the Efficacy of a Prototype Corneal Endothelium Protector during Cataract Surgery.

Purpose. We evaluated the efficacy and safety of a mechanical device, the P-chute, in corneal endothelium preservation during phacoemulsification in a rabbit model. Methods. Twenty-four rabbits were randomly assigned into 2 groups. One eye of each rabbit underwent phacoemulsification that simulated the removal of a dense nucleus, with or without the P-chute. Serial slit-lamp examinations, anterior segment optical coherence tomography (ASOCT) scans, and specular microscopy were performed. Three rabbits from each group were sacrificed on postoperative days (PODs) 1, 5, 7, and 14. Histological analysis of the corneas was performed. Results. There was a trend towards lesser endothelial cell loss for the P-chute group at POD1 (4.9% versus 12.5%, p = 0.53), POD5 (10.4% versus 12.2%, p = 0.77), and POD7 (10.5% versus 17.2%, p = 0.52). There was no significant difference in the corneal thickness (p = >0.05) between the 2 groups. The insertion of the device was challenging. The use of the P-chute only added an extra 15% to the surgical time. Conclusions. There was a trend towards better endothelium preservation with the P-chute even though the results were not statistically significant. We believe that the device could be useful in certain surgical situations. Further work is needed to improve the device insertion.

Bandgap Restructuring of the Layered Semiconductor Gallium Telluride in Air.

A giant bandgap reduction in layered GaTe is demonstrated. Chemisorption of oxygen to the Te-terminated surfaces produces significant restructuring of the conduction band resulting in a bandgap below 0.8 eV, compared to 1.65 eV for pristine GaTe. Localized partial recovery of the pristine gap is achieved by thermal annealing, demonstrating that reversible band engineering in layered semiconductors is accessible through their surfaces.

Strain effects on the work function of an organic semiconductor.

Establishing fundamental relationships between strain and work function (WF) in organic semiconductors is important not only for understanding electrical properties of organic thin films, which are subject to both intrinsic and extrinsic strains, but also for developing flexible electronic devices. Here we investigate tensile and compressive strain effects on the WF of rubrene single crystals. Mechanical strain induced by thermal expansion mismatch between the substrate and rubrene is quantified by X-ray diffraction. The corresponding WF change is measured by scanning Kelvin probe microscopy. The WF of rubrene increases (decreases) significantly with in-plane tensile (compressive) strain, which agrees qualitatively with density functional theory calculations. An elastic-to-plastic transition, characterized by a steep rise of the WF, occurs at ∼0.05% tensile strain along the rubrene π-stacking direction. The results provide the first concrete link between mechanical strain and WF of an organic semiconductor and have important implications for understanding the connection between structural and electronic disorder in soft organic electronic materials.

Comparison of corneal sensitivity, tear function and corneal staining following laser in situ keratomileusis with two femtosecond laser platforms.

PURPOSE: To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK) using two different femtosecond lasers. METHODS: In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT), Schirmer's test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively. RESULTS: There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P > 0.05), although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P < 0.05), 1 month (P < 0 .001), and 3 months (P < 0.001) postoperatively. A significantly greater reduction of corneal sensitivity was noted in eyes with a myopic spherical equivalent of -6.00 diopters (D) to -11.25 D as compared with eyes that had a relatively lower level of myopia of less than -6.00 D (P < 0.001). TBUT and Schirmer's test values were significantly diminished at 1 week postoperatively (P < 0.04). Overall, corneal staining was significantly increased at 1 week postoperatively (P < 0.001). The level of myopia did not significantly affect postoperative changes in TBUT, Schirmer's test values, or corneal staining (P > 0.05). CONCLUSION: This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications.

One Year of Cornea Research in Review-2012.

PURPOSE: The purpose of this study was to provide an update of significant cornea literature published in the past 1 year. DESIGN: This was a literature review. METHODS: The authors conducted a 1-year English-language literature search on PubMed, from January 1, 2012, to December 31, 2012, using the following terms: corneal transplantation, anterior lamellar keratoplasty, penetrating keratoplasty, endothelial keratoplasty, Descemet stripping automated endothelial keratoplasty, Descemet membrane endothelial keratoplasty, Descemet membrane endothelial transfer, ocular surface epithelial transplantation, limbal epithelial transplantation, cultivated oral mucosal epithelial transplantation, keratoprosthesis, infectious keratitis, cross-linking, keratoconus, corneal neovascularization, corneal imaging, optical coherence tomography, Pentacam Scheimpflug imaging, and in vivo confocal microscopy. RESULTS: This review includes original articles and review articles that contain significant updates and novel aspects in the field of cornea from the following journals: American Journal of Ophthalmology, British Journal of Ophthalmology, Ophthalmology, Investigative Ophthalmology and Visual Science, and Cornea. Letters to the editor, unpublished work, manuscripts not in English, and abstracts were not included. CONCLUSIONS: This review highlights significant literature that is applicable to the practicing ophthalmologist.

Reproducibility of Corneal Graft Thickness measurements with COLGATE in patients who have undergone DSAEK (Descemet Stripping Automated Endothelial Keratoplasty).

BACKGROUND: The CorneaL GrAft Thickness Evaluation (COLGATE) system was recently developed to facilitate the evaluation of corneal graft thickness from OCT images. Graft thickness measurement can be a surrogate indicator for detecting graft failure or success. The purpose of this study was to determine the reproducibility of the COLGATE system in measuring DSAEK graft area between two observers. METHODS: This was a prospective case series in which 50 anterior segment OCT images of patients who had undergone DSAEK in either eye were analysed. Two observers (MW, AC) independently obtained the image analysis for the graft area using both semi automated and automated method. One week later, each observer repeated the analysis for the same set of images. Bland-Altman analysis was performed to analyze inter and intra observer agreement. RESULTS: There was strong intraobserver correlation between the 2 semi automated readings obtained by both observers. (r = 0.936 and r = 0.962). Intraobserver ICC for observer 1 was 0.936 (95% CI 0.890 to 0.963) and 0.967 (95% CI 0.942 to 0.981) for observer 2. Likewise, there was also strong interobserver correlation (r = 0.913 and r = 0.969). The interobserver ICC for the first measurements was 0.911 (95% CI 0.849 to 0.949) and 0.968 (95% CI 0.945 to 0.982) for the second. There was statistical difference between the automatic and the semi automated readings for both observers (p = 0.006, p = 0.003). The automatic readings gave consistently higher values than the semi automated readings especially in thin grafts. CONCLUSION: The analysis from the COLGATE programme can be reproducible between different observers. Care must be taken when interpreting the automated analysis as they tend to over estimate measurements.

Deep lamellar keratoplasty after resolution of hydrops in keratoconus.

PURPOSE: Deep anterior lamellar keratoplasty (DALK) using Anwar's big-bubble technique is contraindicated in cases of previous hydrops because of the risk of Descemet membrane (DM) rupture at the hydrops scar. Improved manual lamellar dissection techniques down to the deepest stromal layers now enable manual DALK surgery for previous hydrops with the possibility of obtaining good vision, as an alternative to conventional penetrating keratoplasty. METHODS: Two retrospective case reports of manual DALK in patients with previous hydrops. RESULTS: A 12-year-old boy, with keratoconus and resolved hydrops in his left eye with deep stromal scarring, underwent bilateral manual DALK without baring of the DM. An intraoperative microperforation occurred in his left eye and was managed by intracameral injection of air to seal the perforation. Eleven months after his right DALK and 10 months after his left DALK, his right best spectacle-corrected visual acuity (BSCVA) was 20/20, and his left BSCVA was 20/25. The right cornea was clear, whereas the left cornea had minimal residual deep stromal scarring. Endothelial cell count by specular microscopy was 2611 cells per square millimeter in the right eye and 2193 cells per square millimeter in the left eye. A 28-year-old man, with keratoconus and resolved hydrops in his right eye with deep stromal scarring, underwent right manual DALK without baring of the DM. Nine months postoperatively, his right BSCVA was 20/30, and the graft was clear. Endothelial cell count by specular microscopy was 3148 cells per square millimeter in the right eye. CONCLUSIONS: DALK can be performed in patients with previous hydrops. A controlled deep manual dissection technique without baring the DM is advocated. Good final BSCVA can be achieved despite leaving a thin residual layer of the stroma unexcised.

Effect of intracameral injection of fibrin tissue sealant on the rabbit anterior segment.

PURPOSE: To investigate the effect of intracameral injection of fibrin tissue sealant on the anterior segment structures in a rabbit model. METHODS: One eye of 10 rabbits received an intracameral injection of fibrin tissue sealant with a thrombin concentration of 500 IU (TISSEEL), and the fellow eye received an intracameral injection of balanced salt solution as a control. The rabbits were followed up with serial slit-lamp examinations, photography, high resolution anterior segment optical coherence tomography scans with pachymetry measurement, and intraocular pressure (IOP) monitoring until complete dissolution of the fibrin sealant. Corneal endothelial cell viability was evaluated using live/dead cell assays. Apoptosis of the cornea and trabecular meshwork were evaluated using TUNEL assays. Ultra-structural examinations of the cornea and trabecular meshwork were performed using electron microscopy. Histology of the trabecular meshwork and iris were analyzed using light microscopy. RESULTS: The quantity of the intracameral fibrin sealant was shown to be significantly correlated with increased IOP and pachymetry post-operatively. Complete dissolution of the fibrin sealant occurred between 15 and 30 days. Live/dead cell assays showed no decrease in viability of the corneal endothelium, and TUNEL assays showed no increase in apoptosis of the corneal epithelium, stroma, endothelium, or trabecular meshwork in the eyes with the fibrin sealant. Light and electron microscopy of the anterior segment structures were unremarkable. CONCLUSION: The intracameral use of fibrin glue was associated with a transient increase in IOP and pachymetry. However, there was no evidence of toxicity or structural damage to the corneal endothelium, trabecular meshwork, or iris.

Fungal endophthalmitis after descemet stripping automated endothelial keratoplasty--a case report.

BACKGROUND/AIMS: Descemet stripping automated endothelial keratoplasty (DSAEK) is increasingly gaining popularity as an effective alternative to traditional penetrating keratoplasty for the treatment of endothelial diseases. However, new complications such as donor graft dislocation are seen after DSAEK. Surface venting incisions have been advocated to reduce rates of graft dislocation. We report a case of post-DSAEK fungal endophthalmitis in which the clinical course may have been influenced by the presence of surface venting incisions. METHOD: A retrospective case report. RESULTS: A 72-year-old woman, who developed primary/iatrogenic graft failure after DSAEK, underwent a repeat DSAEK. Corneal venting incisions were reopened at the original sites as her first operation. Early postoperatively, she developed intrastromal opacities, which were thought to be epithelial downgrowth, but progression and increasing stromal and intraocular inflammation required anterior chamber and vitreous tap, which confirmed the presence of Candida parapsilosis, confirming the diagnosis of fungal endophthalmitis. Penetrating keratoplasty, removal of the posterior lamellar graft, removal of the posterior chamber intraocular lens implant (PCIOL) and capsular bag, and anterior vitrectomy were performed after failure of conservative antifungal therapy. Postoperatively, no recurrence of infection occurred, and the graft has remained clear at her most recent follow-up at 6 months, with a best-corrected visual acuity of 20/40. CONCLUSIONS: Corneal venting incisions in DSAEK surgery may be a portal of entry for microorganisms, leading to corneal and intraocular infection, and a high index of suspicion is warranted in the presence of stromal infiltrates or inflammation at venting sites.

Simple antenatal preparation to improve breastfeeding practice: a randomized controlled trial.

OBJECTIVE: To address the impact of simple antenatal educational interventions on breastfeeding practice. METHODS: A randomized controlled trial was carried out in a tertiary referral center from May 2002 to December 2004. A random sample of eligible low-risk antenatal patients was recruited from clinics in the National University Hospital, Singapore. Group A received breastfeeding educational material and individual coaching from a lactation counselor. Group B received breastfeeding educational material with no counseling. Group C received routine antenatal care only. RESULTS: A total of 401 women were recruited. Mothers receiving individual counseling and educational material practiced exclusive and predominant breastfeeding more often than mothers receiving routine care alone at 3 months (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.2-5.4) and 6 months (OR 2.4, 95% CI 1.0-5.7) postpartum. More mothers practiced exclusive and predominant breastfeeding at 6 months among women receiving individual counseling compared with women exposed to educational material alone (OR 2.5, 95% CI 1.0-6.3). CONCLUSION: Where breastfeeding practices are suboptimal, simple one-encounter antenatal education and counseling significantly improve breastfeeding practice up to 3 months after delivery. Provision of printed or audiovisual educational material is not enough. Health care workers should make every effort to have one face-to-face encounter to discuss breastfeeding with expectant mothers before they deliver. CLINICAL TRIAL REGISTRATION: (www.ClinicalTrials.gov), NCT002770192 LEVEL OF EVIDENCE: I.