Influence of Corneal Topographic Parameters in the Decentration of Orthokeratology

Objective: To investigate the lens decentration (LD) of orthokeratology (ortho-k) and the association between pretreatment corneal topographic parameters and LD of the ortho-k. Methods: Fifty right eyes of 50 myopes wearing ortho-k lenses were included in the prospective study. Corneal topography was conducted pretreatment to get topographic corneal parameters, including flat-K (K1); steep-K (K2); corneal astigmatism (CA), CA at 0 to 3 mm (3 mm-CA), 3 to 5 mm (5 mm-CA), 5 to 7 mm (7 mm-CA); surface asymmetry index (SAI); surface regularity index; the curvature of best-fit sphere; the diameter of cornea (DC); the distance from the corneal center to the corneal vertex (CCCV); flat eccentricity (E1), steep eccentricity (E2), and E1/E2 (E ratio); and the corneal curvature differences between the nasal and temporal quadrants at 0 to 3 mm (3 mm-Knt), and the corneal curvature differences between the superior and inferior quadrants at 0 to 3 mm (3 mm-Ksi), 5 mm-Knt (at 3–5 mm), 5 mm-Ksi (at 3–5 mm), 7 mm-Knt (at 5–7 mm), and 7 mm-Ksi (at 5–7 mm). The relationship between these cornea topographic parameters and LD of the ortho-k was tested using stepwise multiple linear regression models. Results: The mean magnitude of LD was 0.51±0.23 mm (0.06–1.03 mm). According to the stepwise analysis, 4 factors were associated with the overall LD (P
Source: Eye and Contact Lens: Science and Clinical Practice - Category: Opthalmology Tags: Article Source Type: research