The similarity in the topographic and pachymetric patterns in eyes with PMD and keratoconus suggests that they may be a continuity of the same disorder with different phenotypes.

Citation: Suzaki A, Maeda N, Fuchihata M, Koh S, Nishida K, Fujikado T. Visual performance and optical quality of standardized asymmetric soft contact lenses in patients with keratoconus. Invest Ophthalmol Vis Sci. 2017;58:289958: -290558: . DOI:10.1167 PURPOSE. To evaluate the visual performance and optical quality of a standardized asymmetric soft contact lens (SCL) used for correction of higher-order aberrations (HOAs) in eyes with keratoconus. METHODS.We included 30 eyes (26 patients) with keratoconus (average K: 45.7 6 2.3 diopters [D]). The patients were subjected to corneal tomography, aberrometry, measurements of manifest refraction and visual acuity (VA), and visual analog scale (VAS) assessments. The study lenses were made using a molding method and consisted of six standardized types, in which an asymmetric power distribution of approximately 2 to 12 D (2-D step) was used to correct HOAs. The lens type suitable for each eye was selected based on the corneal tomography and aberrometry data. The on-eye performance of the lens was evaluated using aberrometry (4-mm pupil), over refraction, VA, and VAS.RESULTS. The standardized asymmetric SCL improved the best spectacle-corrected VA from À0.07 6 0.09 to À0.11 6 0.08 logMAR (P < 0.05) and the mean VAS score from 66.2 6 21.8 to 75.4 6 20.5 (P < 0.05). Vertical coma decreased significantly (À0.50 6 0.36 lm without SCL; À0.36 6 0.34 lm with SCL; P < 0.01). In subgroup analysis, subjects in the high VAS group (score ‡ 75) accounted for 70% of all subjects, and this was the group in which the vertical coma decreased significantly from the level without the lens. CONCLUSIONS.A standardized asymmetric SCL can reduce HOAs and improve vision quality when compared with spectacles in patients with keratoconus who wear rigid gas-permeable lenses.

Chronologic measurements of corneal tomography in keratoconus demonstrated that the progression of steepening at posterior corneal surface was found not only in patients under 30 years but also in older patients, particularly in advanced keratoconus. The rate of progression can be measured by mapping of corneal curvature and thickness using OCT, and the risk of progression was greater in younger patients with steeper Kmax.

Highly myopic eyes had higher-order aberrations than emmetropic eyes because of the increasing internal aberrations.

The dynamic Scheimpflug analyzer provides a method to obtain new biomechanical information on the cornea such as the DA and R hc, and these parameters differed among eyes that had undergone 3 different types of corneal surgery. Abnormalities in these parameters after the different corneal transplantation techniques may indicate larger deviations in the stress-strain reaction of the cornea and more uncertainty in the intraocular pressure measurements than in normal eyes.