J Korean Ophthalmol Soc.  2015 Jul;56(7):1006-1011. 10.3341/jkos.2015.56.7.1006.

Long-Term Effect and Safety of Contact Lenses for Keratoconus

  • 1Department of Ophthalmology, Pusan National University School of Medicine, Busan, Korea. Jiel75@hanmail.net
  • 2YK Eye Clinic, Seoul, Korea.
  • 3Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Korea.


To evaluate the long-term clinical effect and safety of YK-KC lens(R) (LucidKorea Ltd., Seoul, Korea) for keratoconus.
In this study we investigated 152 keratoconic eyes fitted with YK-KC lens(R) and followed up for at least 5 years. We assessed retrospectively self-reported patient comfort, best corrected visual acuity, corneal topographic indices before and after contact lens fitting and complications during contact lens wearing.
The study included 57 male and 40 female patients with a mean age of 28.6 +/- 8.5 years. The mean follow-up was 8.0 +/- 2.9 years. Regarding lens comfort, 126 eyes (82.9%) showed self-reported comfort for YK-KC lenses(R). The mean best corrected visual acuity (log MAR) improved from 0.49 +/- 0.42 before lens fitting to 0.19 +/- 0.27 after lens wearing, which was statistically significant (p < 0.001). Based on the keratometric values, after contact lens fitting both Simulated keratometry (Sim K) max and Sim K min tended to be steeper, but these differences were not statistically significant (p = 0.66 and 0.11, respectively). There were no statistically significant differences between the values before and after fitting with respect to the astigmatic powers (p = 0.22). Complications observed included punctate or coalesced epithelial corneal staining in 24 eyes (16%), however, persistent full-thickness epithelial defect was not observed.
The YK-KC lens(R) in patients with keratoconus can provide excellent visual improvement and comfort without any significant influence on the progression of keratoconus or corneal complications during a long-term follow-up period.


Contact lens; Keratoconus; YK-KC lens(R)

MeSH Terms

Contact Lenses*
Follow-Up Studies
Retrospective Studies
Visual Acuity


  • Figure 1. Distribution of self-reported assessment of contact lens comfort.

  • Figure 2. Change in best-corrected visual activity (BCVA) be-tween spectacles and YK-KC lenses®. Points lying above the solid 45° line correspond to eyes with improved vision with YK-KC lenses®.

  • Figure 3. Distribution of visual acuity when wearing YK-KC lens®, plotted against the base curve radius of the lens. Better visual acuity was achieved when contact lenses with flatter base curve radii were fitted.

  • Figure 4. Correlations between topographic indices and contact lens base curve radius (BCR). 'r' means Pearson's correlation co-efficient between Sim K min and BCR (A), between average of Sim K and BCR (B), between Sim K max and BCR (C), and a rela-tionship is considered to be statistically significant if p < 0.05. Sim K = simulated keratometry; min = minimum.

Cited by  1 articles

The Therapeutic Effect of Sclerocorneal Lens in Coexisting Corneal Ectasia and Stevens-Johnson Syndrome
Jin Uk Baek, Chang Hyun Park, Kyung Sun Na, Hyun Seung Kim
J Korean Ophthalmol Soc. 2018;59(10):968-973.    doi: 10.3341/jkos.2018.59.10.968.



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