Julia Theodossiades

Glaucoma case finding: a cluster-randomised intervention trial

AbstractPurpose To assess the effect of an intervention comprising training in optic disc assessment, explicit referral criteria and ophthalmologist feedback on referred patients, on the number of optometrist referrals for suspected glaucoma seen at a referral site and the positive predictive value of those referrals.Methods Optometric practices routinely referring to the Ealing Hospital Eye Clinic were randomly divided into two groups taking into consideration those practices, which shared an optometrist (a cluster) and the number of optometrist days worked per week. One group of practices acted as controls, while the other practices were invited to receive the intervention. Data on 397 new patients referred and presenting to Ealing Hospital with suspected glaucoma were collected over a 20-month period. The data on patients who had failed to attend their appointment were collected over 7 months of this period. The number of referrals seen, the positive predictive value of those referrals, and the attendance rate were calculated. Optometrists opinions of the intervention were assessed qualitatively. Data relating to optometrist compliance with the intervention were also collected.Results The number of glaucoma referrals presenting to Ealing Hospital from the intervention practices was almost double that from the control practices (210 vs 119). When cluster randomisation, the number of optometrist days per cluster and the number of assessed referrals in the preintervention period are taken into consideration, it is estimated that the intervention is associated with a 52% increase in the number of referrals reaching Ealing Hospital. However, the design effect resulting from the cluster randomisation was unexpectedly high (of the order of 13–14) and so the confidence intervals around the estimate of 52% are very wide (95% c.i. 35% decrease to 253% increase, P=0.34). There was no evidence of an association between optometrist compliance with the intervention and the number of referrals seen at Ealing Hospital. The positive predictive value (PPV) of referrals was similar for the intervention (0.49 (95% c.i. 0.42, 0.55)) and control groups (0.46 (95% c.i. 0.33, 0.60)). Optometrist opinions of the intervention were largely favourable. All expressed a willingness to participate in future programmes.Conclusion A large difference in the number of referrals between the practice groups was observed. Since the PPV of referral was unchanged, the potential impact of the intervention in terms of numbers of new cases of glaucoma detected in the community is substantial. However, because of its large design effect, this trial does not provide conclusive evidence of an impact of the intervention on referral numbers. A considerably larger trial will be required to produce conclusive evidence of an effect.

Glaucoma detection in the community: does ongoing training of optometrists have a lasting effect?

PurposeTo establish whether the effect of improved glaucoma detection in the community suggested by an intervention study is maintained when intervention is extended to include all optometrists in the area.MethodsOptometrists’ in the Ealing, Hammersmith, and Hounslow area were invited to ongoing training sessions following completion of an intervention study. The number of optometrist initiated referrals to Ealing Hospital Eye Clinic (EHEC) for suspect glaucoma was assessed over a 12-month period. The positive predictive value (PPV) of those referrals was calculated and a historical comparison made with the results of the original study.ResultsA total of 376 new referrals for suspected glaucoma were assessed at EHEC during the 12-month period of data collection. This represents an increase in the number of referrals of 58% compared with an equivalent 12-month period during the initial intervention trial (376 vs238). The PPV was maintained at 0.45 (95% CI 0.41–0.51).ConclusionThe rising number of new referrals for glaucoma together with maintenance of the PPV suggests an impact on the number of new cases of glaucoma detected in the community. The increase in referral numbers was limited to glaucoma when compared with new referrals for cataract. This implies a targeted effect of the intervention in terms of glaucoma detection. We believe the next step is to perform the study in an alternative location to see if the effect is repeatable elsewhere. If proven to be the case, there is a coherent argument for widespread adoption of this strategy to improve glaucoma case finding.

What optic disc parameters are most accurately assessed using the direct ophthalmoscope

Purpose It has been suggested that over-reliance on the cup-to-disc ratio is a major factor in the misinterpretation of the optic disc. In spite of this optometrist assessment of the optic disc tends to be restricted to measurement of the cup-to-disc ratio and cup depth only. Would interpretation of the disc improve if optometrists were to evaluate other parameters? The aim of this study was to evaluate the accuracy of optometrist assessment of nine parameters of the optic nerve head using direct ophthalmoscopy.Methods Eight optometrists evaluated nine parameters of the optic nerve head (vertical disc diameter, vertical cup-to-disc ratio, neuroretinal rim configuration, cup shape, neuroretinal rim colour, vessel path, presence/ absence of haemorrhage, extent and location of peripapillary atrophy and classification of health status of the disc) in 50 eyes of 50 patients using direct ophthalmoscopy. Intensive training in optic nerve head assessment was given prior to assessing the patients. Criteria for evaluation were discussed. The ‘gold standard’ reference was the classification of the parameters by a consultant ophthalmologist with a special interest in glaucoma.Results Interobserver agreement for vertical cup-to-disc ratio was almost perfect (mean weighted kappa 0.84). Agreement for neuroretinal rim configuration, cup shape, haemorrhage and final classification of the disc was good (mean kappa 0.62-0.67). There was moderate agreement for vessel configuration (mean kappa 0.53). For assessment of peripapillary atrophy, disc size and neuroretinal rim colour, agreement was fair (mean kappa 0.22-0.34).Conclusions Accuracy of assessment was greatest for vertical cup-to-disc ratio, neuroretinal rim configuration and cup shape. Improved agreement has been demonstrated for the final classification of the disc compared with previous reports. The combination of training and assessment of additional disc parameters appears to improve interpretation of the optic nerve head by optometrists.

Does optometrists’ self-reported practice in glaucoma detection predict actual practice as determined by standardised patients?

Citation information: Theodossiades J, Myint J, Murdoch IE, Edgar DF & Lawrenson JG. Does optometrists’ self‐reported practice in glaucoma detection predict actual practice as determined by standardised patients? Ophthalmic Physiol Opt 2012, 32, 234–241. doi: 10.1111/j.1475‐1313.2012.00898.x

Sensitivity and specificity of two glaucoma case‐finding strategies for optometrists

Current best practice for primary open‐angle glaucoma case‐finding comprises history‐taking, disc examination, intraocular pressure measurement and suprathreshold visual field analysis (SVFA). An alternative case‐finding technique was formulated replacing SVFA with computerised quantitative disc assessment, using the Heidelberg retinal tomograph II (HRT II). Each approach was adopted by four optometrists who screened 29 POAG and 37 normal patients. Average sensitivities and specificities were similar in the two groups [sensitivity 71% (SVFA) vs 69% (HRT II); specificity 94% both groups]. Our inclusion of pre‐perimetric glaucoma cases limited the sensitivity of the optometrists in this study. There was evidence to suggest that the optometrists tended to miss early changes at the optic disc such as disc haemorrhage, nerve fibre layer defects and subtle neuroretinal thinning.

Impact of supply problems of preservative-free glaucoma medications on patients and hospital staff.

Glaucoma is a chronic ocular disease, which is usually managed with long‐term daily medical therapy, in the form of eye drops. Patients who are intolerant to preservatives in topical medicines require preservative‐free versions. From early 2011 patients attending Moorfields Eye Hospital, London, UK, started to report recurring problems with the supply of the following preservative‐free glaucoma medications: Timolol 0.25% (Timoptol 0.25%, MSD UK); Dorzolamide (Trusopt, MSD UK); Dorzolamide and Timolol 0.5% (Cosopt, MSD UK). This study investigates the impact of the supply problems of these medications at Moorfields Eye Hospital from a patient, administrative and clinical perspective.

Anomalies in drug choice in glaucoma clinics

Sir, We investigated anomalies in drug choice when prescribing new glaucoma drops in glaucoma clinics. A total of 1436 records were assessed for 6 months. Of these, 115 patients had a change in drop. An independent glaucoma consultant ophthalmologist categorised the drug choice into three using clearly defined criteria: no anomaly/error, anomaly, error. An anomaly was defined as the prescription of two new drugs simultaneously, prescription of an additional drug without stopping current ineffective drug,1 prescription of a new drug without considering non-adherence,2 and prescription change to unorthodox drug frequency.3 An error was defined as the prescription of a contraindicated drug or a drug with a clearly documented previous adverse drug reaction. Benefit of doubt was given at all times (e.g., multiple changes in drops were considered to be reasonable practice where a pressure rise was an unacceptable risk). We found that over three quarters of changes in medication had consultant or fellow involvement. Optometrists, registrars, and associate specialists, collectively, were responsible for less than a fifth (n=21) of changes in glaucoma drops. There was a high standard of clinical practice in 92 (80%) cases. In one-fifth, therapeutic management was considered to be anomalous or erroneous: there were 15 anomalies in management (13%, 95% CI 7–19%) and 8 errors (7%, 95% CI 2–12%). Seven of these were prescribed a drug with a clearly documented previous adverse reaction and one patient was prescribed Timolol despite advice from their cardiologist to avoid beta blockers. The following risk factors were examined: day of week, time of clinic, patients per clinician, presence of consultant, and staff grade. There was no correlation between these factors and the numbers of errors or anomalies occurring. Errors are inevitable, however, the magnitude reported here is unacceptably high. The majority may be accounted for by a failure to fully examine hospital records, and changes are needed to assist the clinicians in busy clinics. Electronic records accompanied by decision support reduce errors in prescribing.4 We are currently working towards this. Another important step is to encourage shared decision making with patients. The results of the study are being introduced into the glaucoma service induction training.