Predicting ophthalmic clinic non-attendance using machine learning: Development and validation of models using nationwide data.

BACKGROUND: Ophthalmic clinic non-attendance in New Zealand is associated with poorer health outcomes, marked inequities and costs NZD$30 million per annum. Initiatives to improve attendance typically involve expensive and ineffective brute-force strategies. The aim was to develop machine learning models to accurately predict ophthalmic clinic non-attendance. METHODS: This multicentre, retrospective observational study developed and validated predictive models of clinic non-attendance. Attendance data for 3.1 million appointments from all New Zealand government-funded ophthalmology clinics from 2009 to 2018 were aggregated for analysis. Repeated ten-fold cross validation was used to train and optimise XGBoost and logistic regression models on several demographic and clinic-related variables. Models developed using the entire training set were compared with those restricted to regional subsets of the data. RESULTS: In the testing data set from 2019, there were 407 574 appointments (median [range] age, 66 [0-105] years; 210 365 [51.6%] female) with a non-attendance rate of 5.7% (n = 23 309 missed appointments), XGBoost models trained on each region's data achieved the highest mean AUROC of 0.764 (SD 0.058) and mean AUPRC of 0.157 (SD 0.072). XGBoost performed better than logistic regression (mean AUROC = 0.756, p = 0.002). Training individual XGBoost models for each region led to better performance than training a single model on the complete nationwide dataset (mean AUROC = 0.754, p = 0.04). CONCLUSION: Machine learning algorithms can predict ophthalmic clinic non-attendance with relatively basic demographic and clinic data. These findings suggest further research examining implementation of such algorithms in scheduling systems or public health interventions may be useful.

Ophthalmic surgery in New Zealand: analysis of 410,099 surgical procedures and nationwide surgical intervention rates from 2009 to 2018.

BACKGROUND: Surgical intervention rates (SIR) provide a proxy measure of disease burden, surgical capacity, and the relative risk-benefit ratio of surgery. The current study assessed decade trends in ophthalmic surgery and calculated SIRs for all major classes of commonly performed ophthalmic procedures in New Zealand. METHODS: Retrospective population-based analysis of all ophthalmic surgical procedures performed in New Zealand from 2009 to 2018. National and regional datasets from public and private health sectors and industry were analysed. SIRs were calculated for all major ophthalmic procedures, and subgrouped by patient demographics. RESULTS: There were 410,099 ophthalmic surgical procedures completed with a 25.3% overall increase over 10 years. Procedures were mostly government-funded (51%, n = 210,830) with 71% of patients aged over 64 years. Cataract surgery (78%, n = 318,564) had the highest mean SIR (703/100,000/year) and increased by 25% during the study period, consistent with population growth in the over 64 years old age group. Vitrectomy surgery had the second highest mean SIR (67/100,000/year) and increased by 50%, well above national population growth during the study period. Other SIRs included conjunctival lesion-biopsy (38/100,000/year), glaucoma (33/100,000/year), strabismus (20/100,000/year), dacryocystorhinostomy (10/100,000/year), and keratoplasty surgery (4/100,000/year). CONCLUSIONS: This comprehensive review of New Zealand ophthalmic surgery reports increasing SIRs that cannot be explained by population growth alone. Cataract surgery numbers increased year on year consistent with the increase in the over 64 years old population. Vitrectomy surgery growth exceeded that of the national population, including those over 64 years.

Agreement between a new swept-source ocular coherence tomography and a Placido disc-dual Scheimpflug ocular biometric devices.

PURPOSE: To evaluate the agreement between two biometry devices, the Heidelberg Anterion and the Galilei G6 Lens Professional. METHODS: Eyes were scanned with both biometry devices. Analysis of inter-device agreement was conducted for the following metrics: flat (K1), steep (K2) and mean K (Km) for anterior, posterior and total cornea, lens thickness (LT), central corneal thickness (CCT), anterior chamber depth (ACD), white to white (WTW) and axial length (AL). Generalised Estimating Equations were used to account for inter-eye correlation. Bland-Altman analysis was conducted to derive the mean difference (MD) and limits of agreement (LoA) between devices. Differences were deemed clinically significant if they would result in a change in post-operative refraction of 0.25D or more. RESULTS: 159 eyes of 91 patients were included. For the anterior cornea, no significant MD was found for K1 (-0.11D) and K2 (-0.10D), although a significant MD was found for Km (-0.10D). For posterior cornea, while there were no significant MDs between devices, the LoAs were wide for both posterior K1(-0.70, 0.68) and posterior K2 (-1.01, 1.29). For total corneal power, significant MDs were found in K1 (0.36D), and Km (0.26D) but not for K2 (0.17D). Significant MDs were found for LT (0.179mm), CCT (-0.005mm), ACD (-0.111mm) and WTW (-0.158mm), but not for AL (-0.021mm, p > 0.05).Conclusion: There are statistically but not clinically significant differences between Anterion and Galilei G6 Lens Professional in anterior Km, LT, CCT, ACD and WTW. Measurements of the posterior and total cornea are not interchangeable between devices.

Ocular Surface Squamous Neoplasia: A 12-Month Prospective Evaluation of Incidence in Waikato, New Zealand.

Ocular surface squamous neoplasia (OSSN) has a high incidence in the southern hemisphere. This prospective study evaluated the incidence of OSSN in the Waikato region of New Zealand. All patients presenting with pterygium or conjunctival lesions in the Waikato region in 2020 were included. All surgeons in the region were asked to send all conjunctival and corneal specimens excised for histopathologic examination. The primary outcome measure was the incidence of OSSN. Eighty-eight percent of all excised specimens were sent for histopathologic examination. Of the 185 excised lesions sent for histopathological assessment, 18 (10%) were reported as OSSN. Patients were on average 69.4 years of age (standard deviation, SD = 6.9), predominantly male (78%), and of New Zealand-European ethnicity (89%). The OSSN annual incidence was 3.67/100,000/year. Histology grades included conjunctival intraepithelial neoplasia (CIN)-I (25%), CIN-II (25%), CIN-III (12.5%), carcinoma in situ (25%), and invasive squamous cell carcinoma (SCC) (12.5%). One patient with invasive SCC required exenteration. This study identified a high incidence rate of OSSN and is the first prospective study to analyze OSSN epidemiology in New Zealand.

Patient-reported quality of life and eligibility for cataract surgery: assessing the relationship between ethnicity and 'Impact on Life' questionnaire scores in New Zealand.

AIMS: The 'Impact on Life' (IoL) questionnaire is a patient reported quality-of-life assessment tool used to prioritise cataract surgery in New Zealand (NZ). This study evaluated the association between ethnicity and IoL questionnaire responses. METHODS: This is a retrospective cohort study of patients prioritised for public-funded cataract surgery between November 2014 and March 2019 in New Zealand. Data were extracted from the New Zealand Ministry of Health National Prioritisation Web Service database. Ethnic, demographic and IoL data for all patients who were prioritised for surgery were analysed after controlling for age, gender, visual acuity and cataract type. RESULTS: Of the 58,648 prioritisation events, over the four-and-a-half-year period, 46,352 prioritisation events had documented scores for the IoL questionnaire. The study population had a mean age of 74.4 years and had a female preponderance (74%). The average IoL score was 22.5/36 (SD 7.8). After controlling for age, gender, visual acuity (VA) and cataract type, there was only a marginal difference between Maori and non-Maori IoL scores (22.8/36 vs 22.4/36) despite statistical significance for the difference (p=0.001). Maori and Pacific people presented at a younger age (68.5 years and 66.7 years, respectively) with worse visual acuity than other ethnic groups (mean range 70.1-76.7 years). Mean IoL scores were 23.0/36 for Maori and Pacific people and 22.4/36 for other ethnic groups. CONCLUSIONS: Maori and Pacific people present younger with worse VA and more advanced cataracts at time of surgical prioritisation when compared with other ethnic groups. Despite these differences, after controlling for confounding factors, the mean IoL score did not differ to a level that was clinically significant between different ethnic groups in New Zealand at time of prioritisation for cataract surgery. These results suggest that there are no meaningful ethnic specific differences in patient reported quality of life for patients with cataract in New Zealand after controlling for other factors. Alternatively, the IoL tool may lack the sensitivity to detect meaningful ethnic disparities that may exist for quality of life in this cohort of patients.

Improving the provision of cataract surgery in New Zealand demands disruptive change.

Cataract surgery is a highly cost-effective treatment, but the surgical intervention rate in New Zealand ranks poorly compared with other high-income countries. The combination of a growing and ageing population, lost operating time due to the COVID-19 pandemic, and geographical disparities, is driving up an unmet demand for cataract surgery. We present several evidence-based strategies with overlapping benefits in access, equity, efficiency and sustainability. Key strategies include that Health New Zealand mandate a national prioritisation threshold for surgical access, and that PHARMAC leverage cheaper access to surgical supplies using nationally agreed equipment standards, establishing high-throughput cataract units, offering same day bilateral cataract surgery when appropriate, and rationalising post-operative care.

Visual Outcomes of Patients With Peripheral Ulcerative Keratitis and the Effect of Immunosuppression-A 6-Year Experience in Queensland, Australia.

OBJECTIVE: Peripheral ulcerative keratitis (PUK) can cause significant ocular morbidity and mortality. This study aimed to review the effects of systemic immunosuppression on visual outcomes. METHODS: A state-wide, retrospective case series based in Queensland, Australia, was performed. A review of patients who presented with PUK to the major tertiary ophthalmology referral centers between January 2015 and January 2021 was undertaken. Parameters recorded included clinical features at presentation, investigations undertaken, treatment provided, visual outcomes, and mortality outcomes. The effect of immunomodulatory therapy on the change in vision from presentation to the most recent review was analyzed. RESULTS: Twenty-two eyes of 26 patients with PUK (average age 69.81±14.54 years) were included and had a mean follow-up period of 577.73 days. Twelve patients (54.5%) had systemic autoimmune disease, one patient (4.5%) had positive syphilis serology, and nine patients (40.9%) had idiopathic PUK. Eighteen patients (81.8%) were treated with systemic steroids and 10 patients (45.5%) were treated with steroid-sparing immunomodulatory therapy. Average logarithm of the minimum angle of resolution best-corrected visual acuity (BCVA) at presentation and final follow-up were 0.63±0.65 and 0.64±0.82, respectively. Those who were treated with immunomodulatory therapy had a nonstatistically significant improvement in BCVA (-0.10±0.29 with vs. +0.10±0.35 without), and a similar trend was seen for doxycycline (-0.08±0.09 with vs. +0.22±0.49 without). Four of five perforations (80%) were surgically managed. Four patients (18.2%) were deceased. CONCLUSIONS: Peripheral ulcerative keratitis poses significant clinical challenges and requires intensive medical treatment, frequently involving systemic immunomodulatory therapy. Surgical treatment is required in a significant minority of cases. Ocular management alongside the use of doxycycline and immunomodulatory therapy in consultation with specialist physicians can optimize visual and systemic outcomes.

Agreement between 2 SS-OCT biometry devices.

PURPOSE: To assess the agreement between 2 swept-source optical coherence tomography biometry devices, Anterion and IOLMaster 700. SETTING: Tertiary referral center, Brisbane, Australia. DESIGN: Prospective comparative study. METHODS: Bland-Altman analysis was used to assess agreement between devices for flat (K1), steep (K2), and mean (Km) keratometry for anterior, posterior, and total cornea, lens thickness (LT), anterior chamber depth (ACD), central corneal thickness (CCT), white to white (WTW), and axial length (AL). Generalized estimating equations were used to control for within-patient between-eye correlations. Interdevice differences were considered clinically significant if they were likely to alter the spherical refractive outcome by 0.25 diopter (D) or more. RESULTS: 159 eyes of 91 patients (41 male, 50 female) were included. Statistically significant differences were found for K1, K2, and Km for anterior, posterior, and total cornea. When the Anterion was compared with the IOLMaster 700, the mean differences were as follows: anterior K1: -0.17 D, anterior K2: -0.18 D, anterior Km: -0.17 D, posterior K1: -0.38 D, posterior K2: -0.36 D, posterior Km: -0.37 D, total K1: -0.65 D, total K2: -0.82 D, and total Km: -0.74 D. The difference in posterior and total K metrics was clinically significant. Statistically significant differences were noted for LT: 0.159 mm, CCT: -0.004 mm, ACD: 0.054 mm, and WTW: -0.152 mm, although these were not found to be clinically significant. There was no significant difference between devices for AL. CONCLUSIONS: This study found statistically and clinically significant differences for both posterior and total keratometry between the Anterion and the IOLMaster 700. Posterior and total corneal parameters cannot be considered interchangeable between devices.

Diagnostic performance of neuroimaging in suspected idiopathic intracranial hypertension.

The diagnostic utility of neuroradiologic signs associated with idiopathic intracranial hypertension (IIH) for the evaluation of patients presenting with papilloedema remains yet to be elucidated. This multicentre retrospective cohort study assessed consecutive patients presenting with suspected papilloedema to Auckland District Health Board (NZ) and Stanford University Medical Centre (US), between 2005 and 2019, undergoing magnetic resonance imaging and venography (MRI/MRV) or computed tomography and venography (CT/CTV) prior to lumbar puncture assessment for diagnostic suspicion of IIH. Data were collected regarding demographic, clinical, radiologic, and lumbar puncture parameters, and the diagnosis of IIH was determined according to the Friedman criteria for primary pseudotumor cerebri syndrome. A total of 204 participants (174 females; mean ± SD age 29.9 ± 12.2 years) were included, and 156 (76.5%) participants fulfilled the diagnostic criteria for IIH. The presence of any IIH-associated radiologic sign on MRI/MRV demonstrated a sensitivity (95% CI) of 74.8% (65.8%-82.0%) and specificity (95% CI) of 94.7% (82.7%-98.5%), while radiologic signs on CT/CTV exhibited a sensitivity (95% CI) of 61.0% (49.9%-71.2%) and specificity (95% CI) of 100.0% (83.2%-100.0%). In summary, the modest sensitivities of radiologic signs of IIH would support the routine use of lumbar puncture assessment following neuroimaging to secure the diagnosis. However, the high specificities might lend limited support for the judicious deferment of lumbar puncture assessment among typical IIH demographic patients who consent to the inherent small risk of missed pathology, which has been proposed by some clinicians.

Ocular surface squamous neoplasia in New Zealand: a ten-year review of incidence in the Waikato region.

BACKGROUND: Ocular surface squamous neoplasia (OSSN) is a relatively rare disease with a low mortality and highly variable incidence. Despite a high incidence of OSSN in the Southern hemisphere, there is limited epidemiological data for New Zealand. The current study aims to assess the incidence, demographics, and histological grade of OSSN in the Waikato region of New Zealand, home to ~10% of the population of New Zealand. METHODS: Non-interventional retrospective cohort study. All conjunctival biopsy histology reports from 2010 to 2019 in the Waikato region of New Zealand were analysed. Age, sex, and ethnicity were analysed and the incidence of OSSN was calculated. Main outcome measures included histological grade, rate of recurrence, and incidence of OSSN. RESULTS: A total of 386 patients underwent conjunctival biopsy with histology during the study period. Eighty-three lesions (22%) involving 80 patients (21%) were reported positive for OSSN. Patients with OSSN had a mean age of 68.9 years (SD = 13.2), were predominantly male (76%), and of New Zealand-European ethnicity (53%). Conjunctival intraepithelial neoplasia-1 (30%) was the most frequent diagnosis. Three patients (4%) had recurrent lesions requiring repeat biopsy. The peak annual OSSN incidence rate was 3.81/100,000 population in 2019. The overall ten-year incidence was 2.13/100,000 population/year. CONCLUSION: This is the largest study to investigate OSSN incidence in New Zealand. The incidence rate of OSSN is one of the highest rates reported in the literature.

Outcomes of a Toric Monofocal Piggyback Intraocular Lens for Residual Astigmatic Refractive Error in Pseudophakic Eyes.

PURPOSE/AIM: To evaluate the visual outcomes, refractive outcomes and rotational stability of a toric piggyback intraocular lens (1stQ AddOn, GmbH, Mannheim, Germany) for astigmatic refractive error in pseudophakic eyes. MATERIALS AND METHODS: Visual and refractive outcomes were assessed based on the standard graphs for reporting refractive surgery outcomes. Rotational stability was assessed according to the Intraocular Lens (IOL) standards of the International Organisation for Standards. RESULTS: Twenty-two eyes of 17 patients (age: 65.1 ± 9.3 years) underwent toric piggyback IOL insertion. After a minimum follow-up of 3 months, 18 eyes (82%) achieved an uncorrected distance visual acuity (UDVA) of 0.00 logMAR (20/20) or better and all eyes achieved 0.1 logMAR (20/25). Mean UDVA improved from 0.27 ± 0.03 to 0.12 ± 0.03 and 0.04 ± 0.04 at one and 3 months (all p < .05). Nineteen eyes (86%) achieved an UDVA at least equal to the pre-operative corrected distance visual acuity (CDVA). No eyes lost more than one line of CDVA. All eyes achieved within 0.5D of target spherical equivalent (SE). In 18 eyes (82%), the residual astigmatism magnitude was 0.5D or less. The mean absolute difference between the target axis and the achieved axis 1 and 3 months postoperatively was 2.5° ± 2.7° and 3.2° ± 3.3°, respectively. The final IOL orientation was within 10 degrees of target axis in 19 of 22 (86.4%) eyes, within 20 degrees in 21 of 22 (95.2%) eyes and within 30 degrees in 22 of 22 (100%) eyes. IOL rotational repositioning was required in two eyes (9.1%). CONCLUSIONS: In this cohort of patients, the 1stQ AddOn toric monofocal piggyback IOL resulted in very good visual and refractive outcomes and showed reasonable rotational stability. This IOL appears to be an effective treatment option for residual astigmatic refractive error in pseudophakic eyes.

Ferrara Rings for Visual Rehabilitation in Eyes with Keratoconus and Previous Cross-Linking Using the Ferrara Ring Nomogram.

PURPOSE: To report the visual, refractive and tomographic outcomes following the implantation of intrastromal corneal ring segments (ICRS) (Ferrara rings, AJL Ophthalmics, Miñano, Spain) in eyes with a history of keratoconus and corneal cross-linking using the Ferrara ring nomogram. METHODS: Retrospective, interventional case series performed at the Corneoplastics Unit, Queen Victoria Hospital, East Grinstead, United Kingdom. RESULTS: 21 eyes of 19 patients with a history of keratoconus and prior corneal collagen cross-linking had Ferrara Intrastromal Corneal Ring Segments implanted between December 2015 and October 2017. The number, thickness and length of ring segments was chosen based on the Ferrara ring company nomogram. Mean uncorrected visual acuity (UDVA) improved from 0.88 to 0.52 logMAR (p < 0.001). Mean corrected visual acuity (CDVA) improved from 0.47 to 0.36 logMAR (p = 0.046). The percentage of eyes achieving 20/40 UDVA and CDVA increased from 5% to 38% and from 38% to 67%, respectively. Of the eyes, 52.3% gained at least two lines of CDVA. The spherical equivalent improved from -7.51D to -3.76D (p < 0.001) and the refractive astigmatism magnitude improved from 5.14D to 2.76D (p = 0.004). There were significant improvements in the corneal tomography with mean keratometry (KM) improving from 50.40D (3.53) to 48.24D (3.00) (p = 0.01) and keratometric astigmatism magnitude improving from 5.14D (2.91) to 2.76D (1.67) (p = 0.004). CONCLUSION: Insertion of Ferrara rings in keratoconic eyes with a history of prior cross-linking using the company nomogram results in significant improvements in visual, refractive and tomographic outcomes.

Progressive corneal ectatic disease in pregnancy.

Pregnancy influences ocular changes which may exacerbate existing or develop new pathology. This review summarises the existing evidence on the association between pregnancy and progressive keratoconus or iatrogenic keratectasia. Ten online databases were searched systematically. Eligible studies were published in English and reported objective ophthalmic outcomes for women with evidence of (i) a new diagnosis of keratoconus, (ii) keratoconus progression or (iii) iatrogenic keratectasia following refractive surgery; during or within one year of pregnancy. Strength of evidence was assessed using the Oxford Centre for Evidence-Based Medicine levels of evidence. Seventeen articles have reported 33 peripartum women with new-onset or progressive ectasia, evident by signs of corneal hydrops or protrusion (n = 8); steepening on topography imaging (n = 20); a mean decline in best corrected visual acuity by +0.20 logMAR (95% CI -0.01 to +0.40, n = 23); a mean increase in maximum keratometry by 2.18 D (95% CI 1.44 to 2.91, n = 42); a mean decline in spherical equivalent refraction by -1.33 D (95% CI -1.73 to -0.93, n = 41); and a mean increase in astigmatism by -1.61 D (95% CI -2.46 to -0.75, n = 19). Pregnancy is associated with progressive ectasia in some women including those with previously stable keratoconus, or a history of laser-assisted in situ keratomileusis surgery or no history of corneal ectasia. This review highlights the heterogeneity in limited existing evidence, the need for a standardised definition of ectasia progression and further prospective studies for clinical guidelines. Closely monitoring women at risk may assist in early intervention with collagen cross-linking and prevent peripartum vision loss.

Evaluating barriers to access for cataract surgery in Waikato: analysis of calculated driving distance and visual acuity.

AIM: This cross-sectional study aimed to investigate whether presenting visual acuity or patient demographic variables were associated with geographic proximity to primary and secondary ophthalmic services. METHODS: Demographics for all patients referred within the Waikato District between October 2017 and March 2019 that met the threshold for publicly funded cataract surgery were analysed. GPS coordinates for all patient and optometrist addresses were obtained. The driving distance and driving time for each patient to travel to their referring optometrist were calculated. Quality-of-life data were obtained. Analysis of visual acuity, driving distance, age, ethnicity and gender was completed using. Furthermore, a comparative analysis of Maori and New Zealand European defined as having remote access was completed. RESULTS: A total of 1,260 patients were included. Multivariate analysis showed no significant association between driving distance and visual acuity. Comparative analysis of Maori and New Zealand European defined as having remote access showed Maori had significantly worse visual acuity than New Zealand Europeans at the time of referral. No significant difference was found in quality of life. Maori were on average younger than New Zealand European. Driving time and distance were on average 27% longer for Maori compared with New Zealand Europeans defined as having remote access. CONCLUSIONS: Maori presenting with cataract typically are younger and have lower visual acuity than New Zealand European. Longer driving distances represent a potential geographic barrier for Maori to access ophthalmic care and referral to tertiary services. No significant association was found between driving distance and visual acuity.