Ten-year longitudinal investigation of astigmatism: The Yamagata Study (Funagata)

Abstract

Despite numerous investigations into ocular or corneal astigmatism, the dynamic nature of astigmatism remains poorly understood. To reveal potential associations between age and astigmatism, 264 Japanese participants who underwent systemic and ophthalmological examinations in Funagata Town (Yamagata Prefecture, Japan) were evaluated over a 10-year period. Astigmatism was evaluated with regard to the cylinder power, cylinder axis, and vector analyses. Whereas the refractive cylinders showed age-related increases in patients in their 40s to 60s, the corneal cylinders did not change over 10 years. Nevertheless, cylindrical axis of the cornea demonstrated a continuous shift toward against-the-rule (ATR) astigmatism. Vector analyses revealed that the astigmatic shift toward ATR progressed continually after patients reached their 40s, although the shift did not accelerate with age. These novel insights may pave the way for the development of potential strategies for vision correction, including refractive surgeries, and vision-quality maintenance in the elderly.

Evaluation of long-term clinical outcomes after Toric Implantable Collamer Lens implantation

“…Previous studies have reported that corneal astigmatism exhibits a higher proportion of WTR astigmatism in young people and that the proportion of ATR astigmatism increases with age. 15,[18][19][20][21] In this study, corneal astigmatism in 79% of cases changed to ATR astigmatism, supporting the results of previous reports. However, only 42% of the cases with manifest astigmatism converted to ATR.…”

Changes in ocular astigmatism with age: A longitudinal study

“…It has been suggested that these changes from WTR to ATR are due to changes in the eyelid pressure 1 ; however, the evidence is not conclusive. The prevalence of oblique astigmatism is lower and more constant with age than WTR or ATR at between 10%–20% 3,4 and 25%–30% 1 …”

“…2 It has been suggested that these changes from WTR to ATR are due to changes in the eyelid pressure 1 ; however, the evidence is not conclusive. The prevalence of oblique astigmatism is lower and more constant with age than WTR or ATR at between 10%-20% 3,4 and 25%-30%. 1 The change in prevalence from WTR to ATR with age is well documented [1][2][3][4][5] ; however, little has been published regarding how these changes are mediated.…”

“…The prevalence of against‐the‐rule (ATR; negative cylinder axes around 90°) astigmatism increased from approximately 20% in the 21‐ to 30‐year group to 57% in the over‐60s. The change of WTR to ATR astigmatism with age appears to commence from 31 to 40 years 1 or mid‐late 40s 2,3 . A change from an average 0.70 DC WTR in ages 20–49 years to 0.31 DC ATR at 80–89 years, equating to 0.25 DC per decade from age 50 years has been reported and attributed to changes in anterior corneal astigmatism 2 .…”

“…The change in prevalence from WTR to ATR with age is well documented 1–5 ; however, little has been published regarding how these changes are mediated. Specifically, whether small degrees of WTR astigmatism (which are very common at younger ages) rotate through oblique axes, or reduce to zero (spherical prescriptions) to re‐emerge as ATR.…”