Initial experience in self-monitoring of intraocular pressure.

Background/aims: Diurnal variation in intraocular pressure (IOP) is a routine assessment in glaucoma management. Providing patients the opportunity to perform self-tonometry might empower them and free hospital resource. We previously demonstrated that 74% of patients can use the Icare® HOME tonometer. This study further explores Icare® HOME patient self-monitoring. Methods: Patients were trained by standard protocol to use the Icare® HOME rebound tonometer. Patient self-tonometry was compared to Goldmann applanation tonometry (GAT) over one clinical day. Following this, each patient was instructed to undertake further data collection that evening and over the subsequent two days. Results: Eighteen patients (35 eyes) participated. Good agreement was demonstrated between GAT and Icare® HOME for IOPs up to 15 mm Hg. Above this IOP the Icare® tended to over-read, largely explained by 2 patients with corneal thickness >600 um. The mean peak IOP during ‘clinic hours’ phasing was 16.7 mm Hg and 18.5 mm Hg (p = 0.24) over three days. An average range of 5.0, 7.0 and 9.8 mm Hg was shown during single day clinic, single day home and three day home phasing respectively (p =<0.001). The range of IOP was lower in eyes with prior trabeculectomy (6.1 mm Hg vs 12.2 mm Hg). All patients undertook one reading in the early morning at home with an average of 4.8 readings during, and 3.1 readings after office hours. Conclusions: This small study shows that self-tonometry is feasible. The findings from home phasing demonstrated higher peak and trough IOPs, providing additional clinical information. Home phasing is a viable alternative. The cost-effectiveness of this approach has yet to be addressed

Nutrition and Eye Health

Diet is a key lifestyle factor that can have long-term effects on ocular health [...]

Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess whether blue-light filtering spectacle lenses impart effects on visual function, provide protection to the macula, or both. We will also examine potential effects on the sleep-wake cycle

A Critical Appraisal of National and International Clinical Practice Guidelines Reporting Nutritional Recommendations for Age-Related Macular Degeneration: Are Recommendations Evidence-Based?

Eye care professionals should have access to high quality clinical practice guidelines that ideally are underpinned by evidence from robust systematic reviews of relevant research. The aim of this study was to identify clinical guidelines with recommendations pertaining to dietary modification and/or nutritional supplementation for age-related macular degeneration (AMD), and to evaluate the overall quality of the guidelines using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument. We also mapped recommendations to existing systematic review evidence. A comprehensive search was undertaken using bibliographic databases and other electronic resources for eligible guidelines. Quality appraisal was undertaken to generate scores for each of the six AGREE II domains, and mapping of extracted nutritional recommendations was performed for systematic reviews published up to March 2017. We identified 13 national and international guidelines, developed or updated between 2004 and 2019. These varied substantially in quality. The lowest scoring AGREE II domains were for 'Rigour of Development', 'Applicability' (which measures implementation strategies to improve uptake of recommendations), and 'Editorial Independence'. Only four guidelines used evidence from systematic reviews to support their nutritional recommendations. In conclusion, there is significant scope for improving current Clinical Practice Guidelines for AMD, and guideline developers should use evidence from existing high quality systematic reviews to inform clinical recommendations

Corpuscular nerve endings in the human conjunctiva: Relationship to conjunctival touch sensitivity and sensitivity changes in contact lens wear

This study sought to investigate the structure, distribution, and functional significance of complex (corpuscular) nerve endings in the conjunctiva of the human eye. Although these were found to be widely distributed throughout the conjunctiva they were particularly common at the corneo- conjunctival junction and at the eyelid margin. Corpuscular nerve endings were round or oval encapsulated structures which varied in size (mean greatest diameter 40/xm, range 20-78/xm). Each corpuscle was generally served by a single myelinated nerve fibre. The myelin sheath was lost soon after entering the body of the structure. The terminal axon was characterised by multiple beads or varicosities which contained an accumulation of mitochondria. Neural elements were surrounded by cytoplasmic processes of Schwann like cells. The capsule was variable in thickness and typically consisted of fibrocyte processes. In contrast, some corpuscles at the eyelid margin displayed a capsule which contained perineural cells. An intra-vital staining technique using methylene blue was used on the living conjunctiva (N=6). Compared with histological technique this method appears to considerably underestimate the number of complex nerve endings. In an attempt to correlate the position of sensory corpuscles with points of enhanced touch sensitivity an investigation of the sensitivity of the limbal conjunctiva was carried out using a Cochet-Bonnet aesthesiometer. Subjects consisted of both non-contact lens wearers (N=28) and contact lens wearers (N=22) (Hydrogel N=10, RGP N=12). Limbal touch thresholds (LTT) were determined at 18 test locations which were divided equally between the temporal and inferior limbus. Regional variations in LTT were apparent. Thresholds increased with increasing distance from the cornea. Sensitivity was greatest in the region of the conjunctiva corresponding to the palisade zone. This was found histologically to contain a greater concentration of putative receptors. Large inter-subject variations in sensitivity were recorded, and there was an overall reduction with age. A comparison of LTT between lens wearers and non-wearers failed to show any significant differences. The variations in LTT apparent in this study may correlate with the variations in the incidence and local distribution of sensory corpuscles

Care pathways for glaucoma detection and monitoring in the UK

Glaucoma presents considerable challenges in providing clinically and cost-effective care pathways. While UK population screening is not seen as justifiable, arrangements for case finding have historically been considered relatively ineffective. Detection challenges include an undetected disease burden, whether from populations failing to access services or difficulties in delivering effective case-finding strategies, and a high false positive rate from referrals via traditional case finding pathways. The enhanced General Ophthalmic Service (GOS) in Scotland and locally commissioned glaucoma referral filtering services (GRFS) elsewhere have undoubtedly reduced false positive referrals, and there is emerging evidence of effectiveness of these pathways. At the same time, it is recognised that implementing GRFS does not intrinsically reduce the burden of undetected glaucoma and late presentation, and obvious challenges remain. In terms of diagnosis and monitoring, considerable growth in capacity remains essential, and non-medical health care professional (HCP) co-management and virtual clinics continue to be important solutions in offering requisite capacity. National guidelines, commissioning recommendations, and the Common Clinical Competency Framework have clarified requirements for such services, including recommendations on training and accreditation of HCPs. At the same time, the nature of consultant-delivered care and expectations on the glaucoma specialist's role has evolved alongside these developments. Despite progress in recent decades, given projected capacity requirements, further care pathways innovations appear mandated. While the timeline for implementing potential artificial intelligence innovations in streamlining care pathways is far from established, the glaucoma burden presents an expectation that such developments will need to be at the vanguard of future developments

Clinical safety of a minor eye conditions scheme in England delivered by community optometrists

Objective The aim of this study was to monitor the activity and evaluate the clinical safety of a minor eye conditions scheme (MECS) conducted by accredited community optometrists in Lambeth and Lewisham, London. Methods and analysis Optometrists underwent an accredited training programme, including attendance at hospital eye services (HES) clinics. Patients who satisfied certain inclusion criteria were referred to accredited MECS optometrists by their general practitioners (GPs) or could self-refer. Data were extracted from clinical records. A sample of MECS clinical records was graded to assess the quality of the MECS optometrists’ clinical management decisions. Referrals to the HES were assessed by the collaborating ophthalmologists and feedback was provided. Results A total of 2123 patients (mean age 47 years) were seen over 12 months. Two-thirds of the patients (67.3%) were referred by their GP. The most common reasons for patients needing a MECS assessment were ‘red eye’ (36.7% of patients), ‘painful white eye’ (11.1%), ‘flashes and floaters’ (10.2%); 8.7% of patients had a follow-up appointment. Of the patients seen, 75.1% were retained in the community, 5.7% were referred to their GP and 18.9% were referred to the HES. Of the HES referrals, 49.1% were routine, 22.6% urgent and 28.3% emergency. Of the records reviewed, 94.5% were rated as appropriately managed; 89.2% of the HES referrals were considered appropriate. Conclusion The findings of this study indicate that optometrists are in a good position to work very safely within the remits of the scheme and to assess risk

A Portable Infrasonic Detection System

During last couple of years, NASA Langley has designed and developed a portable infrasonic detection system which can be used to make useful infrasound measurements at a location where it was not possible previously. The system comprises an electret condenser microphone, having a 3-inch membrane diameter, and a small, compact windscreen. Electret-based technology offers the lowest possible background noise, because Johnson noise generated in the supporting electronics (preamplifier) is minimized. The microphone features a high membrane compliance with a large backchamber volume, a prepolarized backplane and a high impedance preamplifier located inside the backchamber. The windscreen, based on the high transmission coefficient of infrasound through matter, is made of a material having a low acoustic impedance and sufficiently thick wall to insure structural stability. Close-cell polyurethane foam has been found to serve the purpose well. In the proposed test, test parameters will be sensitivity, background noise, signal fidelity (harmonic distortion), and temporal stability. The design and results of the compact system, based upon laboratory and field experiments, will be presented

Delay in presentation to hospital for childhood cataract surgery in India

Purpose Cataract is one of the major causes of avoidable visual disability in children and the aim of this study was to investigate the age at which children with cataract present for surgery at tertiary hospitals across India. Methods: A prospective multicenter study collected data from 9 eye hospitals in 8 states in India. All children admitted for cataract surgery between Nov 2015 and March 2016 were considered eligible. Parents were interviewed at the hospital by trained personnel and socio demographic information, age at diagnosis and at surgery and the relevant clinical data were obtained from the medical records. Mean age, age range at surgery were used and performed logistic regression analyses. Results Parents of 751 consecutive cases were interviewed, of which 469(63%) were boys and 548(73%) were from rural areas. Cataract was bilateral in 493 (66%) and unilateral in 258 (34%); of the unilateral cases, 179 (69%) were due to trauma. The mean age at surgery for ‘congenital’ and ‘developmental’ cataract was 48.2±50.9 and 99.7±46.42 months respectively and the mean age was lower in the southern region compared to other regions. Children with 2 or more siblings at home were five times more likely to undergo surgery within 12 months (OR, 4.69; 95% CI: 2.04 – 10.79; p = <0.001). Conclusions Late surgery for childhood cataract remains a major challenge and the factors determining this issue in India are pertinent also to several other countries and need to be addressed for every child with cataract to achieve full visual potential

Evaluation of a minor eye conditions scheme delivered by community optometrists

BACKGROUND: The establishment of minor eye conditions schemes (MECS) within community optometric practices provides a mechanism for the timely assessment of patients presenting with a range of acute eye conditions. This has the potential to reduce waiting times and avoid unnecessary referrals to hospital eye services (HES). OBJECTIVE: To evaluate the clinical effectiveness, impact on hospital attendances and patient satisfaction with a minor eye service provided by community optometrists. METHODS: Activity and outcome data were collected for 12 months in the Lambeth and Lewisham MECS. A patient satisfaction questionnaire was given to patients at the end of their MECS appointment. A retrospective difference-in-differences analysis of hospital activity compared changes in the volume of referrals by general practitioners (GPs) from a period before (April 2011-March 2013) to after (April 2013-March 2015) the introduction of the scheme in Lambeth and Lewisham relative to a neighbouring area (Southwark) where the scheme had not been commissioned. Appropriateness of case management was assessed by consensus using clinical members of the research team. RESULTS: A total of 2123 patients accessed the scheme. Approximately two-thirds of patients (67.5%) were referred by their GP. The commonest reasons for patients attending for a MECS assessment were 'red eye' (36.7% of patients), 'painful white eye' (11.1%) and 'flashes and floaters' (10.2%). A total of 64.1% of patients were managed in optometric practice and 18.9% were referred to the HES; of these, 89.2% had been appropriately referred. First attendances to HES referred by GPs reduced by 26.8% (95% CI -40.5% to -13.1%) in Lambeth and Lewisham compared to Southwark. CONCLUSIONS: The Lambeth and Lewisham MECS demonstrates clinical effectiveness, reduction in hospital attendances and high patient satisfaction and represents a successful collaboration between commissioners, local HES units and primary healthcare providers