ABSTRACT
AIMS: To derive an evidence base for the efficacy of two novel optometric primary eye care services in Wales, the Primary Eyecare Acute Referral Scheme (PEARS) and the Welsh Eye Health Examination (WEHE). METHODS: A Donabedian model using structure, process and outcome was applied to evaluate prospectively 6432 individuals attending 274 optometrists within an 8-month period. Telephone interviews and review of optometric and hospital notes were used to determine management appropriateness for patients either managed in optometric practice or referred to the Hospital Eye Service (HES). A Geographic Information Systems analysis determined distances travelled to the optometrist. A cost analysis was used to determine the net cost of the schemes. RESULTS: 4243 (66%) of the 6432 individuals were managed in optometric practice; inappropriate management was apparent in 1% of individuals. 392 hospital notes were reviewed; 75% exhibited appropriate optometric referrals to the HES. 87% of individuals travelled less than 5 miles to attend an optometrist. The net cost of a PEARS/WEHE consultation was a minimum of pound12. CONCLUSIONS: Optometric management within the schemes is acceptable. Good equity of access was achieved at a relatively low net cost per consultation. Agreement on protocols for referral to the HES would enhance the schemes.
Subject(s)
Delivery of Health Care/organization & administration , Optometry/organization & administration , Primary Health Care/organization & administration , Adult , Aged , Delivery of Health Care/economics , Female , Health Care Costs/statistics & numerical data , Health Services Accessibility/statistics & numerical data , Health Services Research/methods , Humans , Male , Middle Aged , Models, Organizational , Optometry/economics , Outcome Assessment, Health Care , Patient Satisfaction , Primary Health Care/economics , Prospective Studies , Quality of Life , Referral and Consultation , WalesABSTRACT
AIMS: To compare monoscopic and stereoscopic assessment of the optic disc using novel software for the digital stereoscopic analysis of optic disc stereopairs. METHODS: Software was developed for the stereoscopic display of digital optic disc images using an interlaced display method. Neuroretinal rim width was determined at 10 degree intervals around the optic disc using a custom (stereoscopic) cursor whose depth was adjusted to that of Elschnig's rim. Measurements were taken, first viewing the disc monoscopically and at a separate sitting, stereoscopically. RESULTS: Measurements were made in 35 eyes from 35 patients (1260 estimates for each observer) using three observers. The mean cup to disc ratio (CDR) ranged from 0.57 to 0.66 (SD 0.13-0.14) for monoscopic viewing compared with 0.64 to 0.69 (SD 0.12-0.14) for stereoscopic viewing. Stereoscopic assessments gave higher CDRs in temporal, superior, nasal, and inferior aspects of the optic disc (p<0.001, Mann-Whitney U test). Agreement between observers in estimating CDR was high for monoscopic assessment (intraclass correlation coefficient 0.74 (CI 0.72 to 0.76) increasing to 0.80 (0.78 to 0.82) for stereoscopic assessment. CONCLUSION: Digital stereoscopic optic disc assessment provides lower estimates of neuroretinal rim width and higher levels of interobserver agreement compared with monoscopic assessments.
Subject(s)
Glaucoma/pathology , Image Interpretation, Computer-Assisted/methods , Optic Disk/pathology , Adult , Aged , Aged, 80 and over , Humans , Middle Aged , Observer Variation , Photography/methods , SoftwareABSTRACT
PURPOSE: To evaluate the diagnostic power of a novel digital stereoscopic imaging system in the diagnosis of glaucomatous optic neuropathy. DESIGN: Prospective cross-sectional analysis of the diagnostic accuracy of digital stereoscopic optic disc analysis in the diagnosis of glaucomatous optic neuropathy exhibiting mild to moderate field loss. PARTICIPANTS: Fifty-two patients with open-angle glaucoma and 54 normal individuals were recruited. The presence of a reproducible visual field loss characteristic of glaucoma was used as the reference standard for the presence of glaucoma independent of the optic nerve head appearance. Patients were excluded if the optic disc, fundus, or visual field indicated other disease. One eye from each patient and individual was included in the study, the eye with the least field loss and a randomly designated normal eye, respectively. METHODS: Simultaneous stereoscopic optic disc photography was performed on each specified eye. Three experienced observers viewed the resultant stereoscopic image of each nerve head using a Z screen, recorded a subjective clinical diagnosis, and undertook digital stereoscopic planimetry. Separate linear regression analysis was performed, post hoc, from the planimetric results for each observer of the logarithm of neuroretinal rim (NRR) against optic disc area derived from each normal eye. Eyes with NRR areas below the 95th prediction interval of the normal cohort were then classified as glaucomatous. MAIN OUTCOME MEASURES: Sensitivity and specificity for the detection of glaucomatous optic neuropathy. RESULTS: With subjective stereoscopic analysis, sensitivity for glaucoma detection among the 3 observers was 80.8%, 76.9%, and 90.4%, with respective specificities of 94.4%, 79.6%, and 79.6%. Regression analysis of the NRR in 30 degrees segments gave sensitivities between 69.2% and 80.8% and specificities between 83.3% and 90.7%. A combination of the subjective and quantitative analysis did not significantly improve discrimination. CONCLUSIONS: The subjective analysis of digital stereoscopic images provides a useful method for the discrimination of normal and glaucomatous optic nerves. Planimetric analysis does not significantly improve the diagnostic precision of this technique.
