Glaucoma treatment and deprivation: time-series analysis of general practice prescribing in England.

BACKGROUND: Despite advances in glaucoma management, topical eyedrop treatment has been paramount, with prostaglandin analogues (PGAs) being first-line agents. While late presentation is linked with deprivation, there is no recent research examining associations between deprivation and prescribing within primary care. AIM: To explore PGA prescribing in general practice over a 6-year timeline, assessing for associations with deprivation. DESIGN & SETTING: Analysis of NHS Business Services Authority data for general practice prescribing in England from April 2016-March 2022. METHOD: Glaucoma treatments by GP prescriber were extracted, identifying ~9.11-9.58 million prescriptions/annum. Data were linked to indices of multiple deprivation (IMD) quintiles of GP practices. Crude rates per 1,000 population were calculated using population data from NHS Digital. Time-series analyses facilitated comparison in prescribing nationally and in deprived areas. Autoregressive Integrated Moving Average (ARIMA) modelling facilitated measurement of synchrony between time-series using cross correlation. RESULTS: PGAs and fixed combination eyedrops account for approximately two-thirds of glaucoma-related prescribing. Prescriptions per month increased slightly over a 6-year timeline, but rates per 1,000 of population reduced in 2020-21. PGA prescriptions dispensed in deprived areas is lower than all other quintiles. Cross-correlation analysis indicates a lag of ~12 months between average PGA prescribing nationally versus more deprived areas. CONCLUSION: The rate of PGA prescribing in primary care is substantially lower in deprived versus affluent areas, with delayed uptake of PGAs in more deprived areas of ~12 months. Further research is needed to explore reasons for this discrepancy, permitting strategies to be developed to reduce unwarranted variation.

Providing capacity in glaucoma care using trained and accredited optometrists: A qualitative evaluation.

INTRODUCTION: The role of optometrists in glaucoma within primary and secondary care has been well described. Whilst many studies examined safety and clinical effectiveness, there is a paucity of qualitative research evaluating enablers and barriers for optometrists delivering glaucoma care. The aims of this study are to investigate qualitatively, and from a multi-stakeholder perspective whether optometric glaucoma care is accepted as an effective alternative to traditional models and what contextual factors impact upon their success. METHODS: Patients were recruited from clinics at Manchester Royal Eye Hospital and nationally via a Glaucoma UK registrant database. Optometrists, ophthalmologists, and other stakeholders involved in glaucoma services were recruited via direct contact and through an optometry educational event. Interviews and focus groups were recorded and transcribed anonymously, then analysed using the framework method and NVivo 12. RESULTS: Interviews and focus groups were conducted with 38 participants including 14 optometrists and 6 ophthalmologists (from all 4 UK nations), and 15 patients and 3 commissioners/other stakeholders. Themes emerging related to: enablers and drivers; challenges and barriers; training; laser; professional practice; the role of other health professionals; commissioning; COVID-19; and patient experience. CONCLUSION: Success in developing glaucoma services with optometrists and other health professionals is reliant on multi-stakeholder input, investment in technology and training, inter-professional respect and appropriate time and funding to set up and deliver services. The multi-stakeholder perspective affirms there is notable support for developing glaucoma services delivered by optometrists in primary and secondary care, with caveats around training, appropriate case selection and clinical responsibility.

The PAUL® glaucoma implant: 1-year results of a novel glaucoma drainage device in a paediatric cohort.

PURPOSE: The PAUL® glaucoma implant (PGI) is a novel glaucoma drainage device, which has not been previously reported in paediatric glaucoma management. This study aims to evaluate the safety and effectiveness of the PGI in a paediatric cohort. METHODS: A retrospective evaluation of 25 cases of paediatric PGI surgery (age 8 months to 16 years) was performed at Manchester Royal Eye Hospital between September 2019 and July 2020. Primary outcome measures included failure (intraocular pressure (IOP) > 21 mmHg or < 20% reduction of IOP, removal of the implant, further glaucoma intervention or visual loss. Secondary outcomes included mean IOP, mean number of medications, logMAR visual acuity and complications. RESULTS: Eleven eyes (48%) had a complete success and achieved an unmedicated IOP < 21 mmHg, and 21 eyes (84%) had a qualified success (with or without medications). Four failures were observed, 2 due to hypotony and 2 underwent further surgery (gonioscopy-assisted transluminal trabeculotomy). The mean preop IOP was 30.9 ± 5.9 mmHg (n = 25), falling to 13.5 ± 6.8 mmHg at 1 month, 17.9 ± 7.2 mmHg at 3 months, 13.4 ± 5.1 mmHg at 6 months, 13.2 ± 4.9 mmHg at 12 months and 11.8 ± 4.6 mmHg at 24 months. The mean change in IOP from the preoperative visit to the last visit was a reduction of 19.1 ± 7.7 mmHg. A significant reduction in the number of medications and IOP was demonstrated after PGI (p < 0.0001). Nine patients required removal of the intraluminal Prolene stent from the PGI for further pressure lowering. CONCLUSION: The one- to two-year results demonstrate paediatric PGI has high qualified success rates and effectively reduces IOP and the need for glaucoma medical therapy.

High dose cefuroxime causing retinal toxicity in a patient undergoing trabeculectomy.

PURPOSE: To present a case of severe retinal toxicity secondary to high dose intracameral cefuroxime administered during trabeculectomy glaucoma surgery. We describe the clinical features and management, and describe serial multimodal imaging and electrophysiological findings. Intracameral cefuroxime (ICC) and subconjunctival cefuroxime (SCC) are routinely administered during ocular surgeries to prevent postoperative endophthalmitis. Cefuroxime toxicity with both standard (1mg/0.1mL) and high doses of ICC (2-100mg) and SCC (31.25mg) have been reported. To the best of our knowledge, this is the first report of cefuroxime retinal toxicity in trabeculectomy surgery, which is of particular significance because of the possible differences in pharmacokinetics within the eye. OBSERVATIONS: A 69-year-old male with primary open-angle glaucoma, underwent right trabeculectomy, augmented with mitomycin C (0.2mg/mL). The patient inadvertently received cefuroxime 12.5mg/0.1mL as an intracameral rather than a subconjunctival injection. Within 4 hours, the error was discovered and the patient underwent immediate anterior chamber (AC) washout. His right best-corrected visual acuity was hand movements, and he rapidly developed uveitis including AC cells and moderate vitritis and haze. Optical coherence tomography (OCT) demonstrated serous macular detachment, characteristic schisis-like changes in the outer nuclear layer and ellipsoid zone disruption. Multi-focal electroretinograms (ERG) identified deficits undetected by full-field ERG. He was successfully managed with intensive local topical corticosteroid, non-steroidal therapy and peri-ocular corticosteroid injection. CONCLUSIONS AND IMPORTANCE: As ICC and SCC are routinely used in intra-ocular surgery to prevent endophthalmitis, ophthalmologists need to be aware of this potential complication and consider this in patients with unexplained reduced vision post-operatively. Theatre teams need to be vigilant about potential dilution and administration errors to ensure that the correct concentration and volume of cefuroxime is given via the correct route. We highlight the risks of high dose intracameral injection, including uveitis and retinal toxicity, and the utility of serial OCT, and full-field and multi-focal ERGs in this condition. We report a favourable outcome with significant and rapid improvement in retinal structure and function observed during follow-up. A literature review of the condition is presented.

Surgical technique, perioperative management and early outcome data of the PAUL® glaucoma drainage device.

OBJECTIVES: To describe a surgical technique and early post-operative outcomes for a novel glaucoma drainage device-the PAUL® glaucoma implant (PGI). METHODS: A consecutive cohort study of subjects who had PGI surgery between February 2019 and May 2020 with a minimum of 6-month follow-up. Primary outcome measures included failure (intraocular pressure (IOP) > 21 mmHg or a <20% reduction of IOP, removal of the implant, further glaucoma intervention or visual loss to no light perception). Secondary outcomes included mean IOP, mean number of medications, logMAR visual acuity (VA) and complications. RESULTS: Ninety-nine eyes of 97 patients had a preoperative IOP (mean ± standard deviation) of 28.1 ± 9.0 mmHg, falling to 18.2 ± 6.8 mmHg at 1 month, 17.9 ± 6.7 mmHg at 3 months and 13.6 ± 4.7 mmHg at 6 months. 52 patients had a 12-month mean IOP of 13.3 ± 4.4 mmHg. The mean change in number of medications was a reduction of 2.38 ± 1.48. A significant reduction in the number of medications and intraocular pressure was demonstrated after PGI (p < 0.0001). No significant change was demonstrated in VA (p = 0.1158). A total of nine cases were deemed failures (six had <20% IOP reduction from baseline and three had IOP >21 mmHg). Thirty-eight (38.4%) of eyes had complete success and achieved an unmedicated IOP <21 mmHg. Ninety (90.1%) of eyes were qualified successes (with or without topical medications). Seventy-four (74.7%) eyes have achieved an intraocular pressure of <15 mmHg. Two cases of hypotony were observed. CONCLUSION: This study presents a safe surgical technique, which significantly reduces IOP and number of medications with minimal complications.

Outcomes of Primary Trabeculectomy From Two Same-centre Cohorts 10 Years Apart.

PRECIS: Trabeculectomy can effectively lower intraocular pressure (IOP). A more junior surgeon profile is emerging. Mitomycin C (MMC) has replaced 5-fluorouracil (5-FU) intraoperatively with comparable success rates and a decrease in postoperative antimetabolite administration. PURPOSE: We compare 2-year outcomes for primary trabeculectomy in 2 cohorts, 10 years apart, performed at a large UK teaching hospital. METHODS: Consecutive case series of trabeculectomies at Manchester Royal Eye Hospital between 2004-2005 (Cohort 1/C1) and 2014-2015 (Cohort 2/C2). Preoperative and postoperative data was collected for IOP outcomes and complications. Success was defined as IOP ≥6 and ≤21, ≤18, ≤16, ≤14, or ≤12 mm Hg with/without a ≥20% decrease from preoperative IOP. The need for and absence of postoperative antihypertensive medication defined qualified and complete success, respectively. RESULTS: A total of 186 cases were analyzed [52 (C1), 134 (C2)]. Mean preoperative IOP was 24±10 mm Hg (C1) and 21±7 mm Hg (C2) (P=0.01). Overall, 34 (79%), 33 (77%), 33 (77%), 29 (67%), and 25 (58%) patients in C1 and 88 (70%), 82 (65%), 73 (58%), 64 (51%), and 40 (32%) patients in C2 achieved complete success for IOP ≤21 mm Hg (P=0.33), ≤18 mm Hg (P=0.22), ≤16 mm Hg (P=0.04), ≤14 mm Hg (P=0.09), or ≤12 mm Hg (P=0.004). Similarly, 43 (93%), 40 (87%), 40 (87%), 35 (76%), and 27 (59%) in C1 and 123 (98%), 116 (92%), 106 (84%), 87 (69%), and 58 (49%) in C2 achieved qualified success (P=0.34, 0.37, 0.83, 0.48, and 0.19). In all, 32 (74%), 31 (72%),31 (72%), 28 (65%), and 24 (56%) in C1 and 64 (51%), 63 (50%), 61 (48%), 54 (43%), and 39 (31%) in C2 achieved complete success with ≥20% reduction from preoperative IOP and IOP of ≤21 mm Hg (P=0.01), ≤18 mm Hg (P=0.02), ≤16 mm Hg (P=0.01), ≤1 mm Hg (P=0.02), or ≤12 mm Hg (P=0.006). By same definition, 37 (80%), 36 (78%), 36 (78%), 33 (72%), and 26 (57%) in C1 and 94 (75%), 93 (74%), 90 (71%), 75 (60%), and 58 (46%) in C2 achieved qualified success (P=0.55, 0.69, 0.48, 0.20, and 0.30). Mean IOP at 2 years was 13±5 mm Hg (C1) and 13±4 mm Hg (C2) (P=0.35). Overall, 62% had intraoperative 5-FU in C1; only MMC was used in C2 (P<0.0001). Postoperative 5-FU was administered in 54% versus 22% in C1 and C2, respectively (P<0.0001). Needling rates were not statistically different [42% (C1), 54% (C2)] (P=0.22). CONCLUSIONS: Trabeculectomy is effective in lowering IOP with success comparable across various definitions. MMC replaced 5-FU as intraoperative antimetabolite resulting in reduced need for postoperative antimetabolite but not increased complications.

Trabeculectomy Training: Review of Current Teaching Strategies.

The aim of this paper is to introduce readers to potential strategies available for teaching trabeculectomy surgery. Trainee surgical outcomes and various surgical simulation techniques are discussed, with suggestions on how to measure progress and consideration of relevant educational theories.

Spontaneous Resolution of a Rapidly Formed Dense Cataract Following Nd: YAG Laser Peripheral Iridotomy in a Case of Pigmentary Glaucoma.

A 54-year-old man was referred for a senior opinion. His vision had acutely dropped in his right eye from 6/6 to hand movements following Nd:YAG laser peripheral iridotomy for treatment of pigmentary glaucoma. A dense rosette posterior subcapsular cataract had formed in his right eye rapidly after surgery. Within 4 weeks the cataract resolved spontaneously and his vision returned to 6/6. It is hypothesized that a dual mechanism caused the rapidly formed cataract. Shockwaves stemming from Nd:YAG laser resulted in a reversible misalignment of the lenticular fibers, and localized direct damage to capsule caused osmotic imbalance and fluid collection between lamellae. Restoration of the osmotic balance, repair, and formation of lens fibers and clearing of vacuoles led to the resolution of the cataract. The proximity of the concave iris to the lens equator in pigmentary glaucoma was a predisposing factor. This highlights the importance of exercising great caution in using laser peripheral iridotomy in cases of pigmentary glaucoma, particularly if a higher laser power is used and considering initial conservative management of this complication.

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 utility of genetic testing in 201 preschool children with inherited eye disorders.

PURPOSE: A key property to consider in all genetic tests is clinical utility, the ability of the test to influence patient management and health outcomes. Here we assess the current clinical utility of genetic testing in diverse pediatric inherited eye disorders (IEDs). METHODS: Two hundred one unrelated children (0-5 years old) with IEDs were ascertained through the database of the North West Genomic Laboratory Hub, Manchester, UK. The cohort was collected over a 7-year period (2011-2018) and included 74 children with bilateral cataracts, 8 with bilateral ectopia lentis, 28 with bilateral anterior segment dysgenesis, 32 with albinism, and 59 with inherited retinal disorders. All participants underwent panel-based genetic testing. RESULTS: The diagnostic yield of genetic testing for the cohort was 64% (ranging from 39% to 91% depending on the condition). The test result led to altered management (including preventing additional investigations or resulting in the introduction of personalized surveillance measures) in 33% of probands (75% for ectopia lentis, 50% for cataracts, 33% for inherited retinal disorders, 7% for anterior segment dysgenesis, 3% for albinism). CONCLUSION: Genetic testing helped identify an etiological diagnosis in the majority of preschool children with IEDs. This prevented additional unnecessary testing and provided the opportunity for anticipatory guidance in significant subsets of patients.

Impact of the Manchester Glaucoma Enhanced Referral Scheme on NHS costs.

OBJECTIVES: Glaucoma filtering schemes such as the Manchester Glaucoma Enhanced Referral Scheme (GERS) aim to reduce the number of false positive cases referred to Hospital Eye Services. Such schemes can also have wider system benefits, as they may reduce waiting times for other patients. However, previous studies of the cost consequences and wider system benefits of glaucoma filtering schemes are inconclusive. We investigate the cost consequences of the Manchester GERS. DESIGN: Observational study. METHODS: A cost analysis from the perspective of the National Health Service (NHS) was conducted using audit data from the Manchester GERS. RESULTS: 2405 patients passed through the Manchester GERS from April 2013 to November 2016. 53.3% were not referred on to Manchester Royal Eye Hospital (MREH). Assuming an average of 2.3 outpatient visits to MREH were avoided for each filtered patient, the scheme saved the NHS approximately £2.76 per patient passing through the scheme. CONCLUSION: Our results indicate that glaucoma filtering schemes have the potential to reduce false positive referrals and costs to the NHS.

Long-Term Outcomes and Complications of Baerveldt Glaucoma Drainage Implants in Adults with Glaucoma Secondary to Uveitis.

Purpose: This study investigated the efficacy and safety of Baerveldt glaucoma implants (BGI) in adults with uveitic glaucoma (UG) at the Manchester Uveitis Clinic.Methods: This was a retrospective study of 42 patients with UG who underwent BGI implantation between 2006 and 2015. Primary outcome measures were intraocular pressure (IOP) reduction and number of medications at 5-year follow-up. Three IOP success criteria were chosen: 1.IOP ≤21 mmHg and ≥20% reduction from baseline 2.IOP ≤17 mmHg and ≥20% reduction from baseline and 3.IOP ≤14 mmHg.Results: The mean pre-operative IOP was 29.5 ± 9.5 mmHg on 3.9 antiglaucoma drops. At 5-year follow-up, IOP reduced to 14.4 ± 7.0 mmHg (p < 0.005) on 1.4 drops. The cumulative probability of failure at 5 years based on criteria 1, 2, and 3 was 24.3%, 39.6%, and 56.3%, respectively.Conclusion: This study demonstrated that BGI are safe and effective in refractory UG, especially in younger adults with complex uveitis.

Incidence, management and outcome of raised intraocular pressure in childhood-onset uveitis at a tertiary referral centre.

BACKGROUND/AIMS: To investigate the incidence, management and outcome of uveitis and raised intraocular pressure (IOP) in children treated at the Manchester Uveitis Clinic (MUC). METHODS: This was a retrospective, observational study of patients who presented with uveitis under the age of 16 to the MUC from July 2002 to June 2016. RESULTS: A total of 320 children were included in the study. Out of these, 55 (17.2%) patients (75 eyes) were found to have raised IOP requiring treatment. The mean age at diagnosis of uveitis and at first recorded raised IOP was 8.2±4.3 and 10.8±3.6 years, respectively. The pre-treatment IOP was 32.3±6.6 mm Hg and the IOP at the final visit was 15.5±3.7 mm Hg (median follow-up period, 43.7 months) on a median number of 0 medications. Twenty-eight eyes (37.3%) required glaucoma drainage surgery, and eight eyes (12.5%) had cyclodiode laser before this. Kaplan-Meier analysis showed that 11.5% of eyes required glaucoma surgery at 1 year after diagnosis of raised IOP, increasing to 50.0% by 5 years. The best-corrected visual acuity at diagnosis of uveitis was 0.26±0.42 logMAR, which remained stable at 0.28±0.65 logMAR at final follow-up visit. Four eyes (5.3%) from four patients fulfilled the definition of blindness by the WHO criteria. The mean cup:disc ratio at final follow-up was 0.4. CONCLUSION: Our cohort of children with raised IOP appeared to have a good outcome overall through aggressive medical and surgical management. Regular long-term follow-up is recommended, and early surgical intervention in eyes with uncontrolled IOP can prevent loss of vision.

Clinical effectiveness of the Manchester Glaucoma Enhanced Referral Scheme.

BACKGROUND: Glaucoma referral filtering schemes have operated in the UK for many years. However, there is a paucity of data on the false-negative (FN) rate. This study evaluated the clinical effectiveness of the Manchester Glaucoma Enhanced Referral Scheme (GERS), estimating both the false-positive (FP) and FN rates. METHOD: Outcome data were collected for patients newly referred through GERS and assessed in 'usual-care' clinics to determine the FP rate (referred patients subsequently discharged at their first visit). For the FN rate, glaucoma suspects deemed not requiring referral following GERS assessment were invited to attend for a 'reference standard' examination including all elements of assessment recommended by National Institute for Health and Care Excellence (NICE) by a glaucoma specialist optometrist. A separate 33 cases comprising randomly selected referred and non-referred cases were reviewed independently by two glaucoma specialist consultant ophthalmologists to validate the reference standard assessment. RESULTS: 1404 patients were evaluated in GERS during the study period; 651 (46.3%) were referred to the Hospital Eye Service (HES) and 753 (53.6%) were discharged. The FP rate in 307 assessable patients referred to the HES was 15.5%. This study reviewed 131 (17.4%) of those patients not referred to the HES through the GERS scheme; 117 (89.3%) were confirmed as not requiring hospital follow-up; 14 (10.7%) required follow-up, including 5 (3.8%) offered treatment. Only one patient (0.8%) in this sample met the GERS referral criteria and was not referred (true FN). There were no cases of missed glaucoma or non-glaucomatous pathology identified within our sample. CONCLUSION: The Manchester GERS is an effective glaucoma filtering scheme with a low FP and FN rate.

Precipitants of 5-Fluorouracil in Trabeculectomy Bleb Management: A Comparative Laboratory Study.

AIM: Concerns regarding 5-Fluorouracil (5-FU) corneal toxicity have resulted in various ways of reducing its corneal exposure during post-operative trabeculectomy bleb manipulation. This study investigates the properties of various topical agents used to induce the precipitation of this compound. MATERIALS AND METHODS: This is a double-blind, descriptive, laboratory study comparing five different potential precipitants of 5-FU (proxymetacaine (proxy), oxybuprocaine (oxy), ametho-caine (ameth), fluorescein (flor), proxymetacaine + fluorescein (proxy-flor) to a control group (normal saline). A 0.01 mL of each anonymized agent was applied next to a clear round comparison marker in a transparent sterile container set on a dark background. 5-FU (0.01 mL of 50 mg/mL) was subsequently applied to each agent. The induced changes in transparency were imaged and compared to the transparency of the central marker. For each application, pH changes were also noted. RESULTS: Proxy, flor and proxy + flor did not result in any discernible 5-FU precipitation. Oxy resulted in a moderate visible change, and ameth produced very significant precipitation. Application of proxy, oxy, ameth, and proxy + flor resulted in the neutralization of the 5-FU's alkaline pH. CONCLUSION: We propose using a cotton-tipped bud dipped in ameth applied at the injection site as the recommended method to avoid 5-FU corneal exposure in these cases. CLINICAL SIGNIFICANCE: Practitioners should be aware of the differences in precipitation of 5-FU by different types of topical anesthetics and modify techniques of anesthesia and 5-FU administration accordingly.How to cite this article: Mercieca KJ, Fenerty CH, Steeples LR, Drury B, Bhargava A. Precipitants of 5-Fluorouracil in Trabeculectomy Bleb Management : A Comparative Laboratory StudyJ Curr Glaucoma Pract 2018;12(2):64-66.

Diagnostic Performance and Repeatability of a Novel Game-Based Visual Field Test for Children.

Purpose: To demonstrate utility of a game-based test ("Caspar's Castle") for the detection of visual field defects in children. Methods: A validity and reliability study was carried out at Manchester Royal Eye Hospital Pediatric Ophthalmology Outpatients Department. We recruited 108 children with no eye pathology (aged 4-12 years) and examined a single eye with the Caspar's Castle system using either normal thresholds or thresholds artificially adapted to recreate defects to assess diagnostic utility. Number of peripheral stimuli missed was used to determine sensitivity and specificity of artificial defect detection and to plot receiver-operator characteristic curves. A further 21 children (aged 4-16 years) with pathology were recruited and Caspar's fields compared qualitatively with established field testing. A total of 106 of the Caspar's Castle examinations were able to be performed twice and repeatability was determined through coefficient of repeatability and Bland-Altman chart. Results: In diagnostic testing using children with no eye pathology, 45 children completed a test using normal thresholds and 43 with tests using artificial defects. Area under receiver-operator characteristic curves for artificial defect detection was 0.895. Of the 21 children with pathology, seven had completed standard Humphreys field testing and Caspar's Castle fields corresponded with each of these by expert opinion. Coefficient of repeatability for number of points missed across all cohorts of children (106 patients) was 6.9 (95% confidence interval: 6.16-8.07). Conclusions: The Caspar's Castle system of assessing visual fields using novel game-based strategies demonstrates encouraging levels of sensitivity, specificity, and reliability. It could help address current difficulties in perimetry in young children.