J Korean Ophthalmol Soc.  2016 Nov;57(11):1714-1722. 10.3341/jkos.2016.57.11.1714.

Corneal Collagen Crosslinking in Progressive Keratoconus

• Hong KE
• Whang WJ
• Chung SH
• Joo CK

• KMID: 2357726
• DOI: http://doi.org/10.3341/jkos.2016.57.11.1714

Abstract

PURPOSE
To report the clinical efficacy and safety of progressive keratoconic eyes in Korean patients treated with accelerated corneal cross-linking.
METHODS
This retrospective study focused on progressive keratoconic eyes in Korean patients that underwent accelerated corneal cross-linking from February 2015 to October 2015. Keratoconus was diagnosed in 45 eyes in 30 patients. After accelerated corneal cross-linking with VibeX rapid solution, best corrected visual acuity, maximum keratometry, mean keratometry, corneal thickness, corneal astigmatism, and endothelial cell count were measured at the preoperative visit and post operation 1 week, 1 month, 3 months, and 6 months.
RESULTS
Best corrected visual acuity (log MAR) was 0.51 ± 0.23 at pre operation and 0.51 ± 0.26 at post operation 6 months, showing no improvement. The maximum keratometry measured with Auto K, Pentacam, and Orbscan II at pre operation was 49.11 ± 4.5 D, 48.37 ± 3.31 D, and 48.98 ± 4.88 D and changed to 49.29 ± 4.34 D, 46.99 ± 3.63 D, and 47.01 ± 3.62 D postoperatively, respectively. Only Pentacam and Orbscan II measurements showed a statistically significant decrease (p < 0.05). Corneal thickness (at the thinnest area) was measured with Pentacam and Orbscan II; pre-operative and post-operative 6 month data showed changes from 485 ± 26.27 and 479.24 ± 27.89 to 471.64 ± 27.12 and 472.52 ± 25.36, respectively. Only the Pentacam method resulted in a statistically significant decrease. Endothelial cell count was measured with confocal microscopy and showed a statistically significant difference between pre-operative 2,857 ± 390.49/mm² and post-operative 6 month 2,639.21 ± 249.92/mm².
CONCLUSIONS
This 6-month follow-up study of Korean keratoconus patients who underwent accelerated corneal cross-linking indicates that the method is effective in stabilizing the progression of keratoconus, according to maximum keratometry change. With regard to endothelial cell count change, further long-term evaluation is required. Other than endothelial cell count change, this procedure is expected to show long-term safety comparable to that of conventional corneal cross-linking.

Keyword

Corneal collagen cross-linking; Keratoconus; Keratometry

MeSH Terms

Astigmatism
Collagen*
Endothelial Cells
Follow-Up Studies
Humans
Keratoconus*
Methods
Microscopy, Confocal
Retrospective Studies
Treatment Outcome
Visual Acuity
Collagen

Figure

• 

  Figure 1. Visual acuity changes in patients. The mean log MAR ± standard deviation, uncorrected and corrected distance visual acuity of patients with keratoconus with thin corneas before and after the accelerated corneal collagen cross-linking. CXL = corneal collagen cross-linking; UDVA = uncorrected distance visual acuity; CDVA = corrected distance visual acuity.

• 

  Figure 2. Keratometric changes in patients. The mean ± standard deviation of keratometric changes in Auto Kmax, Pentacam Kmax, ORB scan Kmax before and 1 week, 1 month, 3 month, and 6 months after the accelerated corneal collagen crosslinking in patients with keratoconus with thin corneas. CXL = corneal collagen cross-linking.

• 

  Figure 3. Image of demarcation line. Corneal stromal demarcation line image with anterior segment optical coherence tomography 1 month after accelerated corneal collagen cross-linking ([CXL] 8 minutes at 30 mW/cm2, total surface dose of 7.2 J/cm2).

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