Posters

Looking beyond keratometry in the detection of early progression in keratoconus

Poster Details

First Author: J. Reddy INDIA

Co Author(s):    K. Challa   V. Singh   S. Palla   H. Ali   P. Vaddavalli        

Abstract Details

Purpose:

To analyze the corneal tomographic parameters in progressive keratoconus and compare them to eyes which didnt show progression

Setting:

Tej Kohli Cornea Institute, L V Prasad Eye Institute, Hyderabad, India.

Methods:

Retrospective evaluation of medical records and topography scans of keratoconus patients who had 2 scans with an interval of atleast 3 months beween the 2 scans. Demographics, uncorrected and best corrected distance visual acuty (UCVA, BCVA), spherical equivalent (SE) and 55 corneal parameters measured at each visit using a single Scheimpflug imaging system were analysed. Thiry- four eyes were included in the progression group (Group1) and 46 eyes in non-progression group (group2). Progression was defined as more than 1 diopter increase in steep or flat anterior keratometry (K).

Results:

Demographics, UCVA, BCVA, mean anterior steepK and flatK were comparable between groups. Posterior steepK, flatK, and steep true net power, pachymetry at pupil center, apex, thinnest pachymetry and Ambrósio’s relational thickness–maximum were statistically significantly different between the two visits in group1 compared to group2 (p<0.001). Among the corneal aberrations anterior, posterior primary spherical aberrations and posterior vertical coma showed a similar trend. Receiver operating characteristic curve analysis of all the above parameters showed high sensitivity but low specificity in detecting early progression. Anterior steepK showed a sensitivity of 83% and specifcity of 73% with a cut-off value of 62.2D.

Conclusions:

Changes in parameters other than anterior keratometry may be considered as relevant warning signs when monitoring progressive keratoconus. Steep anterior keratometry still remains a gold standard parameter in detecting early progressive keratoconus. There is a need for a prospective study to access the evolution of corneal topographic and tomographic parameters in progressive keratoconus.

Financial Disclosure:

NONE