Portable devices for diagnosis and monitoring of glaucoma: a scoping review protocol

INTRODUCTION

Glaucoma is the leading cause of irreversible blindness in the world. The need to diagnose glaucoma early in its natural history before extensive sight loss occurs cannot be overemphasised. However, glaucoma is largely asymptomatic in the early stages of the disease making it complex to diagnose clinically and requires the support of technology. The objective of this scoping review is to determine the nature and extent of the evidence for use of portable devices in the diagnosis of glaucoma.

METHODS

We will consider studies conducted in all healthcare settings using portable devices for the detection of all type of adult glaucoma. We will also include any systematic reviews or scoping reviews, which relate to this topic. Searches will be conducted in MEDLINE, Embase, CENTRAL on the Cochrane Library and Global Health databases, from their inception to the present. Reference lists from publications identified in the searches will also be reviewed. Two authors will independently screen titles and abstracts, followed by full-text screening to assess studies for inclusion. Any disagreements will be discussed and resolved with a third author. Tables accompanied by narrative descriptions will be employed to discuss results and show how it relates to review questions.

ETHICS AND DISSEMINATION

Ethical approval is not required in this review. Only published and publicly accessible data will be used. We will publish our findings in an open-access, peer-reviewed journal and develop an accessible summary of results and recommendations.

Outcomes of newly referred patients with suspected angle closure: do we need to redefine the clinical pathways?

BACKGROUND/OBJECTIVES

To investigate outcomes of referrals for suspected angle closure and explore whether anterior segment optical coherence tomography (AS-OCT) can be used to tighten triaging criteria in a glaucoma virtual clinic.

SUBJECTS/METHODS

Retrospectively collected data. The first audit (04/2018-03/2019) identified referrals for suspected angle closure without other glaucoma-related findings (primary angle closure suspect (PACS) referrals). All patients underwent gonioscopy. The second audit (04-08/2019) identified patients with suspected angle closure in a virtual clinic. Management outcomes were assessed, using gonioscopy as reference standard. The outcomes of the second audit were re-audited after changing the triaging criterion from angle width <10° to iridotrabecular contact (ITC) in ≥1 quadrants on AS-OCT.

RESULTS

Out of 1754 glaucoma referrals (first audit), 24.6% (431/1754) were PACS referrals. Of these, only 10.7% (42/393) had an occludable angle on gonioscopy, with 97.6% (41/42) being PACS. Of these, 78% (32/41) underwent laser peripheral iridotomy. Out of 137 referrals in the virtual clinic (second audit), 66.4% (91/137) were triaged to the face-to-face clinic. Of these, 31.9% (29/91) were discharged. AS-OCT had positive and negative predictive value of 74.3% (95% confidence intervals (CI) 57.8-86.0) and 82.1% (95% CI 70.0-90.2%), respectively, in detecting ITC in ≥1 quadrants. In the re-audit 45.9% (45/98) of those with suspected angle closure were triaged for gonioscopy, with 24.4% (11/45) of them being discharged.

CONCLUSION

PACS referrals represent a substantial burden to hospital-based services and their accuracy is low. ITC in ≥1 quadrants on AS-OCT can be useful in triaging those who need further evaluation with gonioscopy.

Determinants of late presentation of glaucoma in Hong Kong

BACKGROUND

Glaucoma is the commonest cause of irreversible blindness worldwide. As it is typically asymptomatic until advanced, the risk of blindness from late presentation is higher than other eye diseases. This study aims to investigate the risk factors for late presentation of primary glaucoma patients.

METHODS

We undertook a hospital-based case-control study of a random sample of glaucoma patients from a hospital in Hong Kong. Structured questionnaires and existing information from the electronic patient record were used, and the odds of presenting late were analysed by logistic regression.

RESULTS

Of 210 recruited participants, 83 (39.5%) presented with advanced glaucoma unilaterally or bilaterally. The mean age of participants was 61.1 ± 11.9 years, with 110 males (52.4%). Univariate analysis revealed that male sex and primary angle-closure glaucoma (PACG) have 3.06 (CI95:1.71-5.48; P < 0.001) and 2.47 (CI95:1.11-5.49; P = 0.03) times higher odds of late presentation, respectively. Multivariate analysis revealed late presenters were 3.54 (CI95:1.35-9.35; P = 0.01) times more likely to have PACG than primary open-angle glaucoma (POAG). Patients with elevated baseline intraocular pressure (IOP) also had 1.06 times higher odds of presenting with advanced glaucoma (CI95:1.02-1.11; P = 0.002). Linear regression revealed that PACG patients present with 7.12 mmHg higher IOP than POAG patients (CI95:4.23-10.0; P < 0.001).

CONCLUSION

In conclusion, a high proportion of glaucoma patients present late in Hong Kong, with gender and type of glaucoma being significant determinants. Our study shows that PACG presents with higher IOP and, along with male gender, are more likely to have advanced disease than POAG.

A Case of Secondary Pigment Dispersion Following Laser to Cosmetically Lighten the Irises

Eye color is the latest physical attribute to be subject to alteration for cosmetic reasons. We report a rare case of bilateral secondary pigment dispersion following laser burns to the irises for cosmetic purposes. This case demonstrates a case of secondary pigment dispersion not previously reported in the literature to the best of our knowledge.

Severe Hypotony-induced Intraocular Inflammation after Removal of Ripcord Suture from a Glaucoma Drainage Device in Uveitis Patient

Purpose: To report a case of exuberant anterior chamber inflammation post partial removal of supramid® stent.Methods: Case report.Results: The sudden intraocular pressure drop induced by partial removal of ripcord suture from a glaucoma drainage device can result in blood-retinal and blood-aqueous barrier breakdown, inducing uveitis.Conclusions: Intensive inflammatory prophylaxis prior to maneuvers to reduce intraocular pressure may reduce the risk of severe intraocular inflammation in patients with a previous history of uveitis as a consequence of sudden hypotony.

What Glaucoma Surgical Rate could Serve as a Target for West Africa? A Systematic Review

Aim and objective

This study aimed to use the available evidence to model a glaucoma surgical rate (GSR), which could serve as a target for West Africa.

Materials and methods

A comprehensive literature search was performed in Medline, Embase, Global Health, and CINAHL, and studies published between January 1, 2000, and June 19, 2020, were retrieved. Study selection, quality appraisal, and data extraction were performed and the results of individual studies aggregated and presented using a narrative synthesis. Using these data, we aimed to construct a target GSR per million population per year that is sufficient to offer trabeculectomy to most patients with glaucoma who are diagnosed, and for whom other treatment options are either ineffective or inappropriate. The findings were then used to develop a trabeculectomy target for West Africa.

Results

Initial searches returned 633 references, of which 33 unique studies were eligible for inclusion. The glaucoma prevalence population-based surveys identified, reported a wide range of prevalence of primary open-angle glaucoma (POAG) ranging from 1.0 to 8.4%. The studies on glaucoma medications reported intraocular pressure (IOP)-lowering effects ranging from 12.8% (beta-blockers) to 63.7% (Timolol–Latanoprost combinations). The adherence rate to antiglaucoma medications spanned from 10.3 to 82.3%. Regarding selective laser trabeculoplasty (SLT), only two studies were found. All the studies on trabeculectomy showed a significant reduction in IOPs at different follow-up periods with many reporting the absence of vision-threatening complications. From these available data, a GSR of 50 trabeculectomies was suggested for countries in West Africa.

Conclusion

This trabeculectomy target metric is expected to minimize POAG blindness in the West African subregion.

Clinical significance

The proposed GSR will enable eye care workers involved in glaucoma care in West Africa to assess their efforts compared with the proposed target. The gap will signal the potential for improvement.

How to cite this article

Eni EN, Nolan W, Eval B, et al. What Glaucoma Surgical Rate could Serve as a Target for West Africa? A Systematic Review. J Curr Glaucoma Pract 2021;15(1):19–27.

Ophthalmologists' practice patterns and challenges in achieving optimal management for glaucoma in Nigeria: results from a nationwide survey

PURPOSE OF THE STUDY

Glaucoma, a chronic non-communicable disease, and leading cause of irreversible blindness worldwide is a public health problem in Nigeria, with a prevalence of 5.02% in people aged ≥40 years. The purpose of this nationwide survey was to assess Nigerian ophthalmologists' practice patterns and their constraints in managing glaucoma.

STUDY DESIGN

Ophthalmologists were sent a semistructured questionnaire on how they manage glaucoma, their training in glaucoma care, where they practice, their access to equipment for diagnosis and treatment, whether they use protocols and the challenges they face in managing patients with glaucoma.

RESULTS

153/250 ophthalmologists in 80 centres completed questionnaires. Although 79% felt their training was excellent or good, 46% needed more training in glaucoma diagnosis and surgery. All had ophthalmoscopes, 93% had access to applanation tonometers, 81% to visual field analysers and 29% to laser machines (in 19 centres). 3 ophthalmologists had only ophthalmoscopes and schiøtz tonometers. For 85%, a glaucomatous optic disc was the most important feature that would prompt glaucoma work-up. Only 56% routinely performed gonioscopy and 61% used slit-lamp stereoscopic biomicroscopy for disc assessment. Trabeculectomy (with/without antimetabolites) was the only glaucoma surgery performed with one mention of canaloplasty. Poor compliance with medical treatment (78%) and low acceptance of surgery (71%) were their greatest challenges.

CONCLUSIONS

This study indicates that a systems-oriented approach is required to enhance ophthalmologist's capability for glaucoma care. Strategies to improve glaucoma management include strengthening poorly equipped centres including provision of lasers and training, and improving patients' awareness and education on glaucoma.

A Population-based survey of the prevalence and types of glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment Survey

Background

Glaucoma is the leading cause of irreversible blindness worldwide. There tends to be a lower reporting of glaucoma in Africa compared to other blinding conditions in global burden data. Research findings of glaucoma in Nigeria will significantly increase our understanding of glaucoma in Nigeria, in people of the West African diaspora and similar population groups. We determined the prevalence and types of glaucoma in Nigeria from the Nigeria National Blindness and Visual Impairment cross-sectional Survey of adults aged ≥40 years.

Methods

Multistage stratified cluster random sampling with probability-proportional-to-size procedures were used to select a nationally representative sample of 15,027 persons aged ≥40 years. Participants had logMAR visual acuity measurement, FDT visual function testing, autorefraction, A-scan biometry and optic disc assessment. Participants with visual acuity of worse than 6/12 or suspicious optic discs had detailed examination including Goldmann applanation tonometry, gonioscopy and fundus photography. Disc images were graded by Moorfields Eye Hospital Reading Centre. Glaucoma was defined using International Society of Geographical and Epidemiological Ophthalmology criteria; and classified into primary open-angle or primary angle-closure or secondary glaucoma. Diagnosis of glaucoma was based on ISGEO classification. The type of glaucoma was determined by gonioscopy.

Results

A total of 13,591 participants in 305 clusters were examined (response rate 90.4 %). Optic disc grading was available for 25,289 (93 %) eyes of 13,081 (96 %) participants. There were 682 participants with glaucoma; a prevalence of 5.02 % (95 % CI 4.60–5.47). Among those with definite primary glaucoma that had gonioscopy (n = 243), open-angle glaucoma was more common (86 %) than angle-closure glaucoma (14 %). 8 % of glaucoma was secondary with the commonest causes being couching (38 %), trauma (21 %) and uveitis (19 %). Only 5.6 % (38/682) of participants with glaucoma knew they had the condition. One in every 5 persons with glaucoma (136;20 %) was blind i.e., visual acuity worse than 3/60.

Conclusion

Nigeria has a high prevalence of glaucoma which is largely open-angle glaucoma. A high proportion of those affected are blind. Secondary glaucoma was mostly as a consequence of procedures for cataract. Public health control strategies and high quality glaucoma care service will be required to reduce morbidity and blindness from glaucoma.

Prevalence of glaucoma in an urban West African population: the Tema Eye Survey

IMPORTANCE

Multiple studies have found an increased prevalence, younger age at onset, and more severe course of glaucoma in people of African descent, but these findings are based on studies conducted outside Africa.

OBJECTIVE

To determine the prevalence of glaucoma in an urban West African population of adults.

DESIGN AND SETTING

A population-based, cross-sectional study of adults 40 years and older conducted from September 1, 2006, through December 31, 2008, from 5 communities in Tema, Ghana.

PARTICIPANTS

Participants from randomly selected clusters underwent a screening examination that consisted of visual acuity, frequency doubling perimetry, applanation tonometry, and optic disc photography. Participants who failed any of these tests were referred for complete examination, including gonioscopy, standard automated perimetry, and stereoscopic optic disc photography.

RESULTS

A total of 6806 eligible participants were identified, and 5603 (82.3%) were enrolled in the study. The field examination referred 1869 participants (33.3%) to the clinic examination, and 1538 (82.2%) came for complete examination. A total of 362 participants were identified as having glaucoma of any type and category. Primary open-angle glaucoma was the underlying diagnosis in 342 participants (94.5%). The prevalence of primary open-angle glaucoma was 6.8% overall, increasing from 3.7% among those 40 to 49 years old to 14.6% among those 80 years and older, and was higher in men than in women in all age groups, with an overall male-female prevalence ratio of 1.5. Of the participants with glaucoma, 9 (2.5%) were blind using World Health Organization criteria, and only 12 (3.3%) were aware that they had glaucoma.

CONCLUSIONS AND RELEVANCE

The prevalence of glaucoma is higher in this urban West African population than in previous studies of people of East or South African and of non-African descent. Strategies to identify affected persons and effectively manage the burden of glaucoma are needed in West Africa.

Cyclodiode laser in the treatment of acute angle closure

AIM

To describe the outcome of using diode laser transscleral cyclophotocoagulation (cyclodiode laser) as a safe technique in managing acute angle closure refractory to conventional treatment.

METHODS

This is a retrospective case series from two ophthalmic units in the United Kingdom. Five patients with acute angle closure refractory to medical and laser treatment underwent cyclodiode laser treatment. Demographic information, symptoms, medical and surgical treatment, visual outcomes, and intraocular pressure (IOP) control were recorded.

CASE REPORTS

All five patients had symptomatic acute angle closure. Conventional management, including topical and systemic medical treatment, laser iridotomy and laser iridoplasty, did not achieve adequate IOP control or relieve symptoms. Emergency cyclodiode laser treatment was performed within 2-23 days of presentation. All patients subsequently required lensectomy at a later date. At final follow-up (6-14 months), all patients had visual acuity of 6/12 or better with well-controlled IOPs (≤ 17 mm Hg). Only one patient was on topical treatment. One patient developed a persistent low-grade anterior uveitis.

DISCUSSION

Cyclodiode laser is a safe alternative to emergency lensectomy or trabeculectomy in cases of acute angle closure, which do not respond to treatment.

Pharmacological and environmental factors in primary angle-closure glaucoma

INTRODUCTION OR BACKGROUND

A large number of drug classes have now been reported to provoke angle closure in high-risk individuals. The mechanism of action can be generalized into three main categories: sympathomimetic, parasympatholytic and idiosyndratic reactions.

SOURCES OF DATA

This review of the ophthalmic literature provides a clinical summary of primary angle-closure glaucoma (PACG) and its management.

AREAS OF AGREEMENT

External stimuli (pharmacological and environmental) may induce acute, and more often, asymptomatic angle closure, which carries a significant risk of glaucoma.

GROWING POINTS

Whenever in doubt, patients at risk of PACG who are starting on drug therapy known to provoke angle closure or aggravate the condition should be referred for detailed gonioscopic examination of the anterior chamber by an ophthalmologist. AREAS FOR DEVELOPING RESEARCH: The use of new imaging methods such as anterior segment optical coherence tomography to assess the presence or risk of angle closure is gaining popularity, and may offer a more rapid method of identifying people who are at risk of sight loss from angle-closure glaucoma precipitated by non-ophthalmological medication.

Research into Glaucoma and Ethnicity (ReGAE) 8: is there a relationship between social deprivation and acute primary angle closure?

OBJECTIVES

Social deprivation as measured by the Index of Multiple Deprivation (IMD) and Townsend scores has been shown to be associated with advanced presentation of primary open angle glaucoma. The aim of this study was to investigate the putative association of social deprivation as a risk factor for acute primary angle closure (APAC) in a UK urban population.

METHODS

Case notes of 139 consecutive patients presenting with APAC at the Birmingham and Midland Eye Centre, Birmingham, UK, were examined. Deprivation was scored using the IMD 2004 and Townsend scores. These score were compared with the West Midlands reference population.

RESULTS

The level of deprivation in patients with APAC was graded according to the IMD quintiles, in which quintile 1 represents the highest level of deprivation and quintile 5 represents the lowest level of deprivation. Of the patients studied, 66.1% (n=90) were from quintiles 1 or 2 (most deprived) whereas 9% (n=12) came from quintile 5 (least deprived), compared with predicted frequencies of 40% and 20%, respectively. Deprivation levels measured by frequency within each IMD quintile were significantly higher in the APAC group compared with the reference population (χ(2), p<0.001).

CONCLUSIONS

In this population patients presenting with APAC were more likely to come from areas with a high level of social deprivation.

Biometric gonioscopy and the effects of age, race, and sex on the anterior chamber angle

AIM

To utilise a novel method for making measurements in the anterior chamber in order to compare the anterior chamber angles of people of European, African, and east Asian descent aged 40 years and over.

METHODS

A cross sectional study on 15 people of each sex from each decade from the 40s to the 70s, from each of three racial groups-black, white, and Chinese Singaporeans. Biometric gonioscopy (BG) utilises a slit lamp mounted reticule to make measurements from the apparent iris insertion to Schwalbe's line through a Goldmann one mirror goniolens. The main outcome measures were BG measurements of the anterior chamber angle as detailed above.

RESULTS

There was no significant difference in angle measurement between black, white, and Chinese races in this study. However, at younger ages people of Chinese race appeared to have deeper angles than white or black people, whereas the angles of older Chinese were significantly narrower (p = 0.004 for the difference in slope of BG by age between Chinese and both black and white people).

CONCLUSION

The failure to detect a difference in angle measurements between these groups was surprising, given the much higher prevalence of angle closure among Chinese. It appears that the overall apparent similarity of BG means between Chinese and Western populations may mask very different trends with age. The apparently more rapid decline in angle width measurements with age among Chinese may be due to the higher prevalence of cataract or "creeping angle closure." However, longitudinal inferences from cross sectional data are problematic, and this may represent a cohort phenomenon caused by the increasing prevalence of myopia in the younger Singaporean population.

A nurse practitioner-led, collaborative, outpatient practice: a case study in outcomes management

To survive, a nurse practitioner-led primary care service must demonstrate that clinical care, patient satisfaction, and financial results are better than those of the competition. Nurse managers must develop a customer-oriented outcomes-management system to ensure the viability of the practice, especially in today's managed care environment. The authors describe how one nurse practitioner-led practice confronted these challenges to establish a successful business and provide opportunities for teaching and research.

Arterial PaCO2 during chronic hyperthermia in sheep

This study was undertaken to determine if the decrease in PaCO2 and the concomitant increase in pHa seen during acute (less than 24 h) hyperthermia in all mammals was modified when the hyperthermia was maintained for periods longer than 1 day. Catheters were placed in the descending aortas of anesthetized ewes (pentobarbital, 30 mg/kg, i.v.). After recovery from the surgery, arterial blood samples were drawn daily during a 7 day control period and an 8 day period of continuous hyperthermia. In all animals PaCO2 decreased and remained low during the entire hyperthermic period. PaCO2 (torr) and Tr (degrees C) were inversely correlated by the equation: PaCO2 = - 6.08 Tr + 267.8 (r = 0.84). There was an initial alkalosis with hyperthermia, however pH tended to decrease after the fifth day of hyperthermia. Calculated bicarbonate decreased during hyperthermia. The evidence suggested that when body temperature was increased in sheep, PaCO2 was maintained at a lower value. The low PaCO2 value was maintained independent of changes in pHa.