External validation of the OHTS-EGPS model for predicting the 5-year risk of open-angle glaucoma in ocular hypertensives

Prediction of visual field progression with serial optic disc photographs using deep learning

AIM

We tested the hypothesis that visual field (VF) progression can be predicted with a deep learning model based on longitudinal pairs of optic disc photographs (ODP) acquired at earlier time points during follow-up.

METHODS

3919 eyes (2259 patients) with ≥2 ODPs at least 2 years apart, and ≥5 24-2 VF exams spanning ≥3 years of follow-up were included. Serial VF mean deviation (MD) rates of change were estimated starting at the fifth visit and subsequently by adding visits until final visit. VF progression was defined as a statistically significant negative slope at two consecutive visits and final visit. We built a twin-neural network with ResNet50-backbone. A pair of ODPs acquired up to a year before the VF progression date or the last VF in non-progressing eyes were included as input. Primary outcome measures were area under the receiver operating characteristic curve (AUC) and model accuracy.

RESULTS

The average (SD) follow-up time and baseline VF MD were 8.1 (4.8) years and -3.3 (4.9) dB, respectively. VF progression was identified in 761 eyes (19%). The median (IQR) time to progression in progressing eyes was 7.3 (4.5-11.1) years. The AUC and accuracy for predicting VF progression were 0.862 (0.812-0.913) and 80.0% (73.9%-84.6%). When only fast-progressing eyes were considered (MD rate < -1.0 dB/year), AUC increased to 0.926 (0.857-0.994).

CONCLUSIONS

A deep learning model can predict subsequent glaucoma progression from longitudinal ODPs with clinically relevant accuracy. This model may be implemented, after validation, for predicting glaucoma progression in the clinical setting.

Risk Calculation in the Medication Arm of the Ocular Hypertension Treatment Study

PURPOSE

Risk assessment is integral to the management of individuals with ocular hypertension (OHTN). This study aims to determine the predictive accuracy of the Ocular Hypertension Treatment Study 5-year risk calculator (OHTS calculator) among treated patients with OHTN by applying it to patients randomized to the Ocular Hypertension Treatment Study (OHTS) medication arm.

DESIGN

Post hoc secondary analysis of a randomized clinical trial.

SUBJECTS

Individuals participating in the OHTS who were randomized to the medication arm. Only participants with complete baseline data in both eyes were included (n = 726).

METHODS

The hazard ratios (HRs) of the medication group in OHTS were compared to the HR used for the OHTS calculator using the z-test statistic to establish the OHTS calculator's generalizability to the OHTS medication arm. The performance of the OHTS calculator among the OHTS medication group was evaluated twice, using both untreated baseline intraocular pressure (IOP) and average treated IOP during the first 24 months for the IOP variable.

MAIN OUTCOME MEASURES

The performance was determined based on the model's accuracy in estimating the risk of reaching an OHTS primary open-angle glaucoma (POAG) end point using calibration chi-square and discriminating between participants who did or did not develop POAG.

RESULTS

The HRs for the OHTS medication arm were not significantly different from those used in the OHTS calculator for untreated OHTN derived from observation arm data (P > 0.1). Based on the calibration chi-square test for the medication group, the OHTS calculator prediction model had good predictive accuracy when using the mean treated IOP and poorer predictive accuracy with the untreated baseline IOP (chi-square 10 and 29, respectively). The model had good discrimination with treated IOP (c-statistic = 0.77), comparable to what has been reported for the OHTS calculator in the OHTS observation group.

CONCLUSIONS

The OHTS calculator can be applied to treated patients with OHTN, and repeat risk calculation after initiating IOP reduction may provide useful information that can aid in disease management.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

A Comprehensive Review of Methods and Equipment for Aiding Automatic Glaucoma Tracking

Glaucoma is a chronic optic neuropathy characterized by irreversible damage to the retinal nerve fiber layer (RNFL), resulting in changes in the visual field (VC). Glaucoma screening is performed through a complete ophthalmological examination, using images of the optic papilla obtained in vivo for the evaluation of glaucomatous characteristics, eye pressure, and visual field. Identifying the glaucomatous papilla is quite important, as optical papillary images are considered the gold standard for tracking. Therefore, this article presents a review of the diagnostic methods used to identify the glaucomatous papilla through technology over the last five years. Based on the analyzed works, the current state-of-the-art methods are identified, the current challenges are analyzed, and the shortcomings of these methods are investigated, especially from the point of view of automation and independence in performing these measurements. Finally, the topics for future work and the challenges that need to be solved are proposed.

A comparative study on efficacy of fixed combination timolol/brinzolamide versus travoprost monotherapy in drug-naïve open-angle glaucoma patients

Background

Glaucoma is most common irreversible cause of blindness in India. First line management of open-angle glaucoma is either beta blockers or prostaglandin analogs monotherapy. Monotherapy rarely achieves target intraocular pressure within 2 years and patients are shifted to combination medications, usually fixed-dose combination.

Objective

To compare travoprost monotherapy and timolol/brinzolamide fixed-dose combination for their intraocular pressure lowering efficacy, their effects on hemodynamic parameters and cup disc ratio reversibility in newly diagnosed drug-naïve open-angle glaucoma patients.

Material and methods

In a 12-week, prospective, randomised, single-blind study, patients were randomised to receive twice daily 0.5% timolol and 0.2% brinzolamide fixed-dose combination (n = 52) or once daily travoprost 0.004% (n = 52). Intraocular pressure, blood pressure, pulse rate and cup disc ratio were compared across treatment groups over 3 months.

Results

Significant reduction (p < 0.001) in intraocular pressure by 27.99% and 30.49% at 12th-week visit as compared with baseline was observed in monotherapy and fixed-dose combination group, respectively. Significant changes in pulse rate (9 beats/min) and systolic blood pressure (2.35 mmHg) was observed in fixed-dose combination group. No cup disc ratio reversibility was observed at the end of study. Conjunctival hyperaemia (n = 14) and transient blurring of vision (n = 16) were most commonly reported adverse drug reaction in monotherapy and fixed-dose combination, respectively.

Conclusion

The 0.5% timolol and 0.2% brinzolamide fixed-dose combination produced greater reduction in intraocular pressure than those produced by 0.004% travoprost alone in drug-naïve open-angle glaucoma patients.

The impact of SIGN glaucoma guidelines on false-positive referrals from community optometrists in Central Scotland

Background

Since the introduction of National Institute for Health and Care Excellence glaucoma guidelines 2009, the number of referrals from community optometrists to hospital eye services has increased across the UK, resulting in increase in first visit discharge rates (FVDRs).

Aim

To assess the impact of Scottish Intercollegiate Guidelines Network (SIGN) 144 on quality of referrals from community optometrists.

Methodology

A retrospective study of patient records who attended as new adult glaucoma referrals to clinics in Princess Alexandra Eye Pavilion, Edinburgh, and in Greater Glasgow and Clyde, was carried out across October–November 2014 (group 1) and September–October 2016 (group 2), before and after the introduction of SIGN 144. The primary outcome of this study is FVDRs. A secondary outcome is the extent of compliance to referral recommendations by SIGN guidelines.

Results

Three hundred and twelve and 325 patients were included in groups 1 and 2, respectively. There was a significant decline in FVDRs between these two periods from 29.2% to 19.2%. (p=0.004) (OR 0.58 (95%CI 0.40 to 0.84)). Post-SIGN guidelines, 87% of referrals were compliant to SIGN referral criteria while 13% remained non-compliant. The main reasons for non-compliance were no repeatable visual field defects (42.0%) and referrals due to high intraocular pressure were either not repeated or not interpreted in the context of age and central corneal thickness (36.8%).

Conclusion

Patients referred after the introduction of SIGN guidelines were 33.5% less likely to be discharged at the first visit. Although compliance to most recommendations in SIGN guidelines has improved, there is still a need to improve adherence to referral criteria

Baseline factors predicting the risk of conversion from ocular hypertension to primary open-angle glaucoma during a 10-year follow-up

PurposeTo evaluate the ability of baseline clinical, morphological, and functional factors to predict the conversion to primary open-angle glaucoma (POAG) in ocular hypertensive (OHT) patients.MethodsThis single-center prospective longitudinal observational study included 116 eyes of 116 OHT patients followed for a 10-year period. All patients had intraocular pressure (IOP) ≥24 mm Hg in one eye and >21 mm Hg in the other eye, normal visual fields (VFs) and normal optic disc (OD) appearance in both eyes at baseline. All OHT patients were untreated at baseline with subsequent treatment upon need according to clinical judgement. Only one eye per subject was randomly selected. Patient age, gender, IOP, central corneal thickness (CCT), and ibopamine test results were collected at baseline. All patients underwent standard automated perimetry, short-wavelength automated perimetry (SWAP), frequency-doubling technology, confocal scanning laser ophthalmoscopy (CSLO), and scanning laser polarimetry (SLP) at baseline and every 6 months thereafter. Main outcome measure was the conversion to POAG, defined as the development of reproducible VF and/or OD abnormalities attributable to glaucoma. Cox proportional hazards models were used to identify the baseline factors predictive of POAG conversion.ResultsDuring the 10-year follow-up, 25% of eyes converted to POAG. In multivariate Cox models, baseline factors that were significant predictors of POAG development included: older age (hazard ratio (HR) 1.0, 99% confidence intervals (CIs) 1.0-1.2, per 1 year older); SWAP Glaucoma Hemifield test 'outside normal limits' (HR 4.3, 99% CIs 1.2-17.9); greater SLP 'Inter-eye Symmetry' (HR 1.1, 99% CIs 0.4-3.0, per 1 unit lower); lower CSLO Rim Volume (HR 1.1, 99% CIs 0.3-3.2, per 0.1 mm(3) lower); and greater CSLO cup-to-disc ratio (HR 6.0, 99% CIs 3.6-16.8, per 0.1 unit greater).ConclusionsThe baseline parameters that proved to be useful in assessing the likelihood of an OHT patient to develop POAG included age, functional variables provided by SWAP, and structural variables provided by SLP and CSLO. In this cohort of patients, baseline IOP, CCT, and ibopamine provocative test results were not significant predictors of POAG conversion.

Treatment of ocular hypertension: is it cost effective?

PURPOSE OF REVIEW

The review evaluates the past 18-month literature related to cost-effectiveness of treating ocular hypertension (OHT) and give an opinion of the state of research.

RECENT FINDINGS

Three studies question the value of intensive monitoring in OHT and glaucoma. One study suggests that implementing Ocular Hypertension Treatment Study - European Glaucoma Prevention Study (OHTS-EGPS) risk prediction in every day practice overestimates the risk of open-angle glaucoma. While two models suggest that treating all intraocular pressures above 21 mmHg would be cost-saving (but disagree on the impact of this strategy on conversion to glaucoma), another study in turn suggests than we could safely reduce medications in almost half of the patients. Two studies suggest that effective early treatment could decrease follow-up costs in OHT and one modeling study suggests that using laser in preference to medication would be cost effective in glaucoma.

SUMMARY

The results of this time-limited review are confusing as they challenge many current beliefs to continue to do more than what we are currently doing. We have a huge gap in understating whether we are currently doing the 'right' things in our every day practices.

Stereo Photo Measured ONH Shape Predicts Development of POAG in Subjects With Ocular Hypertension

PURPOSE

To identify objective, quantitative optic nerve head (ONH) structural features and model the contributions of glaucoma.

METHODS

Baseline stereoscopic optic disc images of 1635 glaucoma-free participants at risk for developing primary open-angle glaucoma (POAG) were collected as part of the Ocular Hypertension Treatment Study. A stereo correspondence algorithm designed for fundus images was applied to extract the three-dimensional (3D) information about the ONH. Principal component analysis was used to identify ONH 3D structural features and the contributions of demographic features, clinical variables, and disease were modeled using linear regression and linear component analysis. The computationally identified features were evaluated based on associations with glaucoma and ability to predict which participants would develop POAG.

RESULTS

The computationally identified features were significantly associated with future POAG, POAG-related demographics (age, ethnicity), and clinical measurements (horizontal and vertical cup-to-disc ratio, central corneal thickness, and refraction). Models predicting future POAG development using the OHTS baseline data and STEP features achieved an AUC of 0.722 in cross-validation testing. This was a significant improvement over using only demographics (age, sex, and ethnicity), which had an AUC of 0.599.

CONCLUSIONS

Methods for identifying objective, quantitative measurements of 3D ONH structure were developed using a large dataset. The identified features were significantly associated with POAG and POAG-related variables. Further, these features increased predictive model accuracy in predicting future POAG. The results indicate that the computationally identified features might be useful in POAG early screening programs or as endophenotypes to investigate POAG genetics.

Protocol-driven adjustment of ocular hypotensive medication in patients at low risk of conversion to glaucoma

AIM

To investigate the safety and potential savings of decreasing medication use in low-risk patients with ocular hypertension (OH).

METHODS

Patients with OH receiving pressure-lowering medication identified by medical record review at a university hospital underwent examination by a glaucoma specialist with assessment of visual field (VF), vertical cup-to-disc ratio (vCDR), central corneal thickness and intraocular pressure (IOP). Subjects with estimated 5-year risk of glaucoma conversion <15% were asked to discontinue ≥1 medication, IOP was remeasured 1 month later and risk was re-evaluated at 1 year.

RESULTS

Among 212 eyes of 126 patients, 44 (20.8%) had 5-year risk >15% and 14 (6.6%) had unreliable baseline VF. At 1 month, 15 patients (29 eyes, 13.7%) defaulted follow-up or refused to discontinue medication and 11 eyes (5.2%) had risk >15%. The remaining 69 patients (107 eyes, 50.7%) successfully discontinued 141 medications and completed 1-year follow-up. Mean IOP (20.5±2.65 mm Hg vs 20.3±3.40, p=0.397) did not change, though mean VF pattern SD (1.58±0.41 dB vs 1.75±0.56 dB, p=0.001) and glaucoma conversion risk (7.31±3.74% vs 8.76±6.28%, p=0.001) increased at 1 year. Mean defect decreased (-1.42±1.60 vs -1.07±1.52, p=0.022). One eye (0.47%) developed a repeatable VF defect and 13 eyes (6.1%) had 5-year risk >15% at 1 year. The total 1-year cost of medications saved was US$4596.

CONCLUSIONS

Nearly half (43.9%) of low-risk OH eyes in this setting could safely reduce medications over 1 year, realising substantial savings.