. 2016 Jan 22;30(4):562–569. doi: 10.1038/eye.2015.274

Table 2b. Summary of clinical studies relating to the magnitude and axis of astigmatism.

Study (first author)	Country	Number (n)	Age, in years	Findings
		Eyes/patients
Hashemi¹⁷	Iran	^a/5020	40–65	Prevalence of ATR/OB astigmatism increased with age. Higher education inversely correlated to magnitude of astigmatism (P≤0.001). Astigmatism was higher in men.
Guan¹	China	1430/827	≥16	45.45% of eyes had >1.00 D of astigmatism. The magnitude of corneal astigmatism was positively correlated with age. Corneal astigmatism shifts with age from WTR to ATR.
Chen⁹	China	4831/2849	40–95	41.3% of eyes had >1.00 D of astigmatism. Corneal astigmatism shifts with age from WTR to ATR.
Ferrer-Blasco¹⁰	Spain	4540/2415	32–87	34.8% of eyes had >1.00 D of astigmatism. Corneal astigmatism <1.25 D was present in most cataract surgery candidates (78%). 13% of cataract surgery candidates do not have corneal astigmatism.
Khan¹²	UK	1230/746	≥30	40.41% of eyes had >1.00 D of astigmatism.
Nemeth²⁴	Hungary	1092/a	≥15	32.78% of eyes had >1.00 D of astigmatism. ATR astigmatism prevalence positively correlated to age.
Hoffmann¹¹	Germany	23 239/15 448	a	8% of eyes had corneal astigmatism >2.00 D, and 2.6% had >3.00 D.
This study	UK	2247/2247	10–109	44.2% of eyes had >1.00 D of astigmatism. ATR astigmatism is more prevalent with increasing magnitude of astigmatism, whereas OB astigmatism is less prevalent.

Not mentioned.