Purchase this article with an account.
Julie Marie Schallhorn, Craig S Schallhorn, Steven C Schallhorn; The Utility of Cycloplegic Refraction: Differences Between Manifest and Cycloplegic Refractions in a Large Population. Invest. Ophthalmol. Vis. Sci. 2014;55(13):2734.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To describe the difference between manifest and cycloplegic refraction in a large population over a wide range of ages and refractive errors.
A retrospective review of patients undergoing manifest (Mrx) and cycloplegic (Crx) refraction at a series of private optical centers (Optical Express, Glasgow, UK). All patients underwent Mrx and Crx by experienced optometrists using a ‘push plus’ technique, Crx was performed 30 minutes after 2 drops of 1% tropicamide were instilled. Data was collected on Mrx and Crx, age, gender, pupil diameter, keratometry and corneal pachymetry. Patients aged 18 to 75 years were included in the study if they had a Mrx and Crx performed at the same visit.
There were 365,325 patients (729,626 eyes) that met inclusion criteria, 276,531 patients (509,199 eyes) were myopic and 88,794 (177,415 eyes) were hyperopic, 51.2% were female. The average age of myopes was 35.5 years, for hyperopes it was 50.8 years (p<0.0001). The average myopic manifest spherical equivalent (MSE) was -3.24 ± 2.14D, the average hyperopic MSE was +2.29 ± 1.57D (range -28.625D to + 20.0D). The average myopic cycloplegic spherical equivalent (CSE) was -3.12 ± 2.18D, and the average hyperopic CSE was +2.58 ± 1.70D. The difference between CSE and MSE was greatest in young hyperopic patients and decreased linearly with age for hyperopic patients by 0.175D (95%CI 0.174 to 0.177) per decade of life. For myopic patients, the CSE was, on average +0.141D (95%CI 0.141 to 0.142) greater than the MSE, and the difference remained stable throughout all ages. A cycloplegic refraction was most likely to detect a refractive difference of 1D or greater between MSE and CSE in hyperopic patients under the age of 50; 19% of patients in this group had a difference of 1D or greater between MSE and CSE. Only 1.2% of myopic patients in the same age group had a difference of 1D or greater between MSE and CSE (p<0.0001).
For hyperopic patients, the greatest difference between MSE and CSE is in younger patients, this difference decreases linearly over time. Myopic patients are much less likely to have a discordance of 1D or greater between MSE and CSE. Nearly one out of five cycloplegic refractions in hyperopic patients between 18 and 50 will yield a difference greater than 1D, whereas only one out of 100 will yield a difference of 1D or greater in myopic patents.
This PDF is available to Subscribers Only