Changes in ocular astigmatism with age: A longitudinal study

Abstract

PurposeTo investigate changes in astigmatism with age. Are changes from with‐the‐rule (WTR) in younger ages to against‐the‐rule (ATR) in older patients mediated through oblique astigmatic axes or spherical prescriptions, and at what ages do these changes occur?MethodsPrescription data were gathered retrospectively from one optical practice belonging to a large multiple group in the UK. Longitudinal assessments were made of the changes in astigmatism for 326 patients (mean age at first prescription 46 years, range 28–69 years) and 640 eyes through their recorded prescription history (median 20 years of prescription data per participant, IQR 19–22 years, range 18–29 years).ResultsChanges in small degrees of astigmatism (0.25 or 0.50 DC) from WTR to ATR were more than three times more likely to pass through an oblique cylinder axis as through a spherical prescription (56 vs. 16, = 22.2, p < 0.0001). For patients aged 28–40 years at their first recorded eye examination, 55% (92/167) of eyes had an onset of astigmatic changes at a mean of 44 years (SD 6.2) and 41% (68/167) of eyes had no change until after a mean of 54 years (SD 4.6). Compared with a measured prevalence of oblique astigmatism in the literature of 11%–19%, 36% (232/640) of the eyes in this study had an oblique cylinder prescribed at least once in their refraction history and of these oblique cylinders, 78% were transient in nature.ConclusionsThe change in ocular astigmatism with age, from WTR to ATR, was more than three times more likely (56 vs. 16) to pass through oblique cylinder axes as through a spherical prescription. Changes in oblique astigmatism have been implicated in complaints with new spectacles, so given this prevalence of oblique cylinder axes (232/640, 36%), continuing professional development is needed regarding reconciling these oblique changes with previous prescriptions.

Astigmatism Management in Modern Cataract Surgery

“…Changes in ocular astigmatism with age have been previously well-documented. Most eyes (55%) do not undergo astigmatic changes (in cylinder power or axis) until their mid-40s with many (41%) not experiencing a change until after their mid-50s [ 4 ]. This transformation is characteristically a conversion from with-the-rule (WTR) to against-the-rule (ATR) astigmatism, which studies have shown are three times more likely to rotate through oblique axes to return as ATR rather than reducing to zero and re-emerging as ATR [ 4 ].…”

“…Most eyes (55%) do not undergo astigmatic changes (in cylinder power or axis) until their mid-40s with many (41%) not experiencing a change until after their mid-50s [ 4 ]. This transformation is characteristically a conversion from with-the-rule (WTR) to against-the-rule (ATR) astigmatism, which studies have shown are three times more likely to rotate through oblique axes to return as ATR rather than reducing to zero and re-emerging as ATR [ 4 ]. Male eyes also exhibit greater and earlier ATR corneal astigmatism compared to female eyes, a sex-related difference with potentially significant implications for astigmatism correction [ 5 ].…”