The Topographical Effect of Optical Zone Diameter in Orthokeratology Contact Lenses in High Myopes

Table 4

Average widths (mm) of optical zone and peripheral rings obtained after 15 days of orthokeratology lenses wear.

	5 mm OZ lens	6 mm OZ lens	value
Nasal PRW	2.3 ± 0.2	1.9 ± 0.1	0.037
OZT	2.8 ± 0.2	3.1 ± 0.1	0.024
Temporal PRW	2.4 ± 0.1	2.2 ± 0.2	0.047

Values are expressed as mean ± SD. SD: standard deviation; OZT: optical zone treatment; PRW: peripheral ring width. value < 0.05; (Student’s t-test for paired samples; 5 mm OZ vs. 6 mm OZ).