Corneal collagen cross-linking for the treatment of pellucid marginal degeneration

Session Details

Session Title: Cross-Linking II

Session Date/Time: Tuesday 16/09/2014 | 16:30-18:00

Paper Time: 17:42

Venue: Boulevard A

First Author: : N.Cagil TURKEY

Co Author(s): :    O. Sarac   M. Caglayan   S. Uysal   E. Akcay     

Abstract Details

Purpose:

To report the visual, refractive, topographic, and clinical outcomes 12 months after corneal collagen cross-linking (CXL) in eyes with pellucid marginal degeneration (PMD).

Setting:

Center of Keratoconus and Refractive Surgery, Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital, Ankara, Turkey.

Methods:

This retrospective study included all consecutively treated PMD patients (15 eyes of 10 patients) with 12 months follow-up period following CXL. The outcome measures were uncorrected visual acuity (UCVA; measured in logarithm of the minimum angle of resolution [logMAR] units), best spectacle-corrected visual acuity (BSCVA; measured in logMAR units), sphere and cylinder on subjective refraction, spherical equivalent, central corneal thickness (CCT), corneal thickness at the thinnest point (t-CCT), simulated flattest keratometry (Sim-K1), simulated steepest keratometry (Sim-K2), average K, apical K, keratoconus vertex front (KVf), and symmetry index front (SIf). The Sirius 3D rotating Scheimpflug camera and topography system (CSO, Florence, Italy) was used for the corneal topographic analysis. Follow-up examinations were arranged at 3, 6, and 12 months.

Results:

The mean UCVA, BCSVA, spherical value on subjective refraction, and spherical equivalent did not show significant change throughout the follow-up period as compared with baseline (p>0.05 for all variables). The UCVA was decreased by one Snellen line in three (20%) eyes 12 months after treatment. The mean cylinder on subjective refraction (-4.11±2.51 diopters (D) and -3.23±2.5 D at baseline and at 12 months, respectively), and the mean topographic cylinder (-6.41±3.80 D and -5.72±3.73 D at baseline and at 12 months, respectively) showed slight decrease throughout 12 months, which were statistically insignificant (p>0.05 for all variables). The mean Sim-K1, Sim-K2, average K, apical K, SIf, and KVf did not show significant change compared with the pretreatment values (p>0.05 for all variables). There were significant reduction in CCT (459.07±44.07 μm, 420.26±38.13 μm, and 431.26±45.72 μm at baseline, at 3 months [p=0.001], and at 6 months [p=0.019], respectively), and t-CCT (429.53±48.95 μm, 395.46±41.23 μm, and 401.46±46.51 μm at baseline, at 3 months [p=0.001], and at 6 months [p=0.016], respectively) throughout the first 6 months after treatment. There was not any significant difference between the mean baseline and final CCT and t-CCT (p>0.05 for both variables) values. No complications were occurred.

Conclusions:

12 month results after CXL in PMD patients demonstrated stable visual acuity, stable refraction, and stable corneal topographic parameters. More studies with longer follow-up periods are needed to assess the duration of the stability of the corneal ectasia in these patient group. Continued stability of the visual outcome and lack of progression of corneal ectasia can make CXL an alternative therapy in PMD.

Financial Interest:

NONE