Posters

Comparison of densitometry changes between two different cross-linking protocols

Poster Details

First Author: J. Lammer AUSTRIA

Co Author(s):    N. Pircher   R. Donner   G. Schmidinger              

Abstract Details

Purpose:

To assess changes in corneal backward light scattering / densitometry values comparing two different crosslinking (CXL) treatment protocols and to investigate the association with K-values (Kmax) over time.

Setting:

Medical University Vienna, Department of Ophthalmology and Optometry, Vienna, Austria

Methods:

Treatment-naive subjects with progressive keratoconus were treated either following the Standard Dresden Protocol (SDP, 30 min Riboflavin + 20% Dextran soaking, 30min irradiation UVX-1000) or an Accelerated epi-off CXL Protocol (ACP, 10min Riboflavin + HPMC [Vibex Rapid] soaking, 10min UVX-2000). Study participants were examined using Scheimpflug tomography (PentacamHR) in order to assess densitometry in different corneal layers at different points in time: Pre-operatively (BL) and 1 month (mo1), 3 month (mo3), 6 month (mo6) and 12 month (mo12) after CXL treatment.

Results:

Both groups (SDP n=42 eyes; ACP n=29 eyes) showed significantly higher densitometry values in the anterior layer (mean±SD, 22.91±3.95) compared to the middle (16.22±2.72) or posterior layer (15.98±2.60) at BL (p=0.0001, respectively). In both groups densitometry values increased significantly from BL by mo1 (ACP: Δ6.32±4.28, p<0.0001) and mo3 (SDP: Δ5.37±4.36, p<0.0001), respectively, before decreasing again. By mo12, densitometry remained increased compared to BL in the SDP group (Δ3.87±5.89, p=0.0001) but returned close to BL values in the ACP group (Δ1.21±4.93, p=0.22). There was no consistent association between densitometry and (Δ) Kmax at any visit of the study.

Conclusions:

Increased stray light / densitometry values 1-3 months after CXL are common but decease to a close-to-normal level within a year after treatment. Differences between treatment protocols are minimal, however, need to be further investigated in bigger cohorts and over a longer period of time. Additionally, Kmax values did not seem to be consistently influenced by changes in densitometry values – and vice versa.

Financial Disclosure:

NONE