Abstract
Data from a glaucoma screening study involving 88.5% of the population age 50 and over of a single handed general practitioner were reanalysed to determine the effect of altering the protocol for intraocular pressure assessment and the effect of changing the referral threshold.
The predictive power of the Keeler Pulsair noncontact tonometer was found to decrease from 22.5% at four pulses per eye to 12.3% when only one pulse per eye was used, with a reduction of sensitivity from 91.7% to 75%.
The sensitivity of the same device fell from 91.7% if all patients with an IOP >21 mmHg were deemed as having a positive screen, to 41.6% when only patients with an IOP >26 mmHg were considered for referral.
To create a balance between high sensitivity and acceptable predictive power of a positive result in a population where 50% of glaucoma sufferers are known prior to screening, we advise that four pulses per eye should be used with an IOP of >22 mmHg used as the significant finding indicating that the patient required referral.
Similar content being viewed by others
Article PDF
References
Hollows FC and Graham PA : Intraocular pressure, glaucoma and glaucoma suspects in a defined population. Br J Ophthalmol 1966, 58: 570–86.
Leske MC, Podgor M, Ederer F : An evaluation of glaucoma screening methods. Invest Ophthalmol Vis Sci 1982, 22 (suppl) 128.
Bengtsonn B : The prevalence of glaucoma. Br J Ophthalmol 1981, 65: 46–9.
Quigley HA, Addicks EH, Green WR : Optic nerve damage in human glaucoma. Arch Ophthalmol 1982, 100: 135–46.
Smith RJH : Ocular hypertension Res Clin Forum 1980, 2: 129–31.
Mills KB : Ocular hypertension Res Clin Forum 1985, 7: 81–4.
Goldmann H : An analysis of some concepts concerning chronic simple glaucoma. Am J Ophthalmol 1975, 80: 409–13.
Vernon SA and Henry DJ : Do optometrists screen for glaucoma? Eye 1989, 3: 743–6.
Vernon SA, Henry DJ, Cater L, Jones SJ : Screening for glaucoma in the community by non-ophthalmologically trained staff using semi-automated equipment. Eye 1990, 4: 88–97.
Jones SJ, Vernon SA, Cater L, Henry DJ : Costing a community based screening programme for the detection of glaucoma. Eye 1990, 4: 98–102.
Leske MC and Hawkins BS : Screening: relationship to diagnosis and therapy. In Duanne TD, Jaeger EA eds. Clinical Ophthalmology. Philadelphia, Philadelphia, Harper and Row, 1987, 3 (54): 1–16.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Vernon, S., Jones, S. & Henry, D. Maximising the sensitivity and specificity of non-contact tonometry in glaucoma screening. Eye 5, 491–493 (1991). https://doi.org/10.1038/eye.1991.80
Issue Date:
DOI: https://doi.org/10.1038/eye.1991.80
This article is cited by
-
Difference in intraocular pressure measurements between non-contact tonometry and Goldmann applanation tonometry and the role of central corneal thickness in affecting glaucoma referrals
Irish Journal of Medical Science (1971 -) (2019)
-
Intra-eye pressure range and pulse profiles in normals with the pulsair non-contact tonometer
Eye (1993)
-
Intraocular pressure asymmetry in a population tested with the Pulsair non-contact tonometer
Eye (1991)