What adjustments, if any, do UK optometrists make to the subjective refraction result prior to prescribing?

Abstract

Aim: To determine whether UK optometrists routinely prescribe the subjective refraction result, or whether adjustments are made to aid patient comfort and adaptation. Method: A questionnaire was distributed by post and via the internet to UK optometrists. It incorporated eight case scenarios that included information regarding a patientÕs age, symptoms, habitual refractive correction, subjective refraction and any other pertinent clinical information. For each case, they were asked to indicate what refractive correction they would prescribe. Results: A total of 426 questionnaires were completed. In three cases with asymptomatic patients with negligible changes in visual acuity, about 45% of respondents indicated that they would prescribe the subjective refraction result and about 40% would prescribe the habitual correction. In a further case involving a 75 year-old asymptomatic patient, 55% prescribed the habitual correction. In two cases with large cylinder power changes, about 40% of respondents indicated they would partially prescribe the cylinder power. However, there was a large variation in the suggested modification of sphere powers to accompany the partial cylinder changes. Conclusion: A large sample of UK optometrists indicated that they would prescribe the subjective refraction result regardless of patient age, symptoms and difference between habitual correction and subjective refraction. Optometrists who partially prescribe, employ a wide variety of techniques including some that conflict with conventional teaching.

Spectacle prescribing II: practitioner experience is linked to the likelihood of suggesting a partial prescription

“…The prescribing of at least 0.50DS from the mean sphere equivalent in one eye in patient B by approximately 4% of partial prescribers and in one or both eyes with patient E by approximately 53% of respondents would very likely result in patient dissatisfaction. 9,10 The relatively high level of practitioners not maintaining the subjective mean sphere equivalent power was similar to those obtained from our first prescribing questionnaire 1 and reiterates the need for continuing education in this area.…”

“…The prescribing recommendation of ''not to push the plus'' for non-progressive myopes 16 or to be ''very cautious about reducing minus at distance with the myopic patient'' 12 can be likened to a modified ''if it ain't broke don't fix it'' prescribing rule discussed previously by Howell-Duffy. 1 The rationale for this recommendation is that by reducing the minus in an asymptomatic myopic patient happy with their current correction, the practitioner only risks creating an unhappy patient. Patient A's occupation of a taxi driver was deliberately chosen to alert practitioners to the possible effect of night myopia on their prescribing decision.…”

“…In particular, the cylindrical power change scenario was engineered to reveal whether practitioners adopted conventionally taught wisdom and maintained the best mean sphere obtained in the refraction [14][15][16] or alternatively prescribed a partial cylinder power with either the habitual or subjective refraction sphere result. Our earlier study 1 suggested that the latter might be the case, but as this was an unexpected finding, the case scenarios were not devised to explicitly assess this possibility. In this study we specifically chose a different sphere power for the habitual and the subjective prescription, to allow easy clarification of whether practitioners had chosen the habitual or subjective sphere when partially prescribing the cylindrical change.…”

“…1 It is likely that spectacle dissatisfaction rates (patients unhappy with their new spectacles either as a result of incorrect prescribing or failure to adapt to the prescription) for UK optometric practices are approximately 2% of all spectacles dispensed [1][2][3] suggesting that approximately 400 000 patients per year return to their optometrist dissatisfied with their spectacles. These patients not only reduce practitioner productivity by taking up an additional eye examination appointment and any associated reglazing costs, but spectacle dissatisfaction can also tarnish a practitioner's professional reputation.…”

Evaluation of the Clinical Maxim: “If It Ain't Broke, Don't Fix It”

“…Previous work by HowellDuffy et al 28,41 suggested that a majority of UK optometrists in general practice would prescribe the subjective refraction result without modification, and this must include cases where only a small change in prescription would have been recommended. Presumably, some of these patients would have been equally satisfied with their existing habitual prescription.…”