Abstract
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.
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References
Bell RWD, O'Brien C . Accuracy of referral to a glaucoma clinic. Ophthalmic Physiol Optics 1997;17:7–11.
Theodossiades J, Murdoch IE . Optometrist case finding and referral for glaucoma: the Ealing Survey. Ophthalmic Physiol Optics 1997;19:62–7.
Newman DK, Anwar S, Jordan K . Glaucoma screening by optometrists: positive predictive value of visual field testing. Eye 1998;12:921–4.
Montgomery DM, Craig JP . Optic disc interpretation in glaucoma: is confidence misplaced? Ophthalmic Physiol Optics 1993;13:383–6.
Sommer A, Pollack I, Maumenee AE . Optic disc parameters and onset of glaucomatous field loss. II. Static screening criteria. Arch Ophthalmol 1979;97:1449–54.
Gross PG, Drance SM . Comparison of a simple ophthalmoscopic and planimetric measurement of glaucomatous neuroretinal rim areas. Glaucoma 1995;4:314–6.
Landis JR, Koch GG . The measurement of observer agreement for categorical data. Biometrics 1977;33:159–74.
Lichter PR . Variability of expert observers in evaluating the optic disc. Trans Am Ophthalmol Soc 1977;74:532–72.
Tielsch JM, Katz J, Quigley HA, Mille NR, Sommer A . Intraobserver and interobserver agreement in measurement of optic disc characteristics. Ophthalmology 1988;95:350–6.
Varma R, Spaeth GL, Steinmann WC, Katz J . Agreement between clinicians and an image analyzer in estimating cup-to-disc ratios. Arch Ophthalmol 1989;107:526–9.
Varma R, Steinmann WC, Scott IU . Expert agreement in evaluating the optic disc for glaucoma. Ophthalmology 1992;99:215–21.
Abrams LS, Scott IU, Spaeth GL, Quigley HA, Varma R . Agreement among optometrists, ophthalmologists, and residents in evaluating the optic disc for glaucoma. Ophthalmology 1994;101:1662–7.
Murdoch IE . The epidemiology of glaucoma and glaucoma-related parameters in rural communities mesoendemic and nonendemic for onchocerciasis, Kaduna State, Northern Nigeria. MD thesis, University of London, 1993.
Tuulonen A, Jonas JB, Valimaki S, Alanko H, Airaksinen PJ . Interobserver variation in the measurements of peripapillary atrophy in glaucoma. Ophthalmology 1996;103:535–41.
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Theodossiades, J., Murdoch, I. What optic disc parameters are most accurately assessed using the direct ophthalmoscope?. Eye 15, 283–287 (2001). https://doi.org/10.1038/eye.2001.95
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DOI: https://doi.org/10.1038/eye.2001.95
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