Posters

Correlation between corneal densitometry and severity of keratoconus

Poster Details

First Author: I.Mine JAPAN

Co Author(s):    N. Kato   S. Ishikawa   M. Takeuchi        

Abstract Details

Purpose:

Keratoconus is an ecstatic disease of the cornea that is usually diagnosed and progresses in puberty. Although the keratoconic cornea is clear and only reveals excessive refractive power that can be corrected by spectacles at an early stage, visual function is disturbed. The corneal aberration and light scattering increase, mainly due to surface irregularity and sometimes due to corneal opacity, as the disease progresses. The purpose of the present investigation was to assess corneal light scattering, expressed as densitometry readings, and its correlation with the severity of keratoconus.

Setting:

Department of Ophthalmology, National Defence Medical College

Methods:

Sixty-three eyes of 43 patients with keratoconus were enrolled (age, 35.4  13.0 years; 26 males and 17 females). In addition to routine ophthalmic examinations, corneal tomography using a Scheimpflug rotating camera (Pentacam HR® system; Oculus, Germany) was performed. Densitometry readings of the corneal surface at the corneal apex and the thinnest corneal thickness were recorded. The correlation of these readings with the topographical keratoconus classification (TKC) were analysed by JMP software version 10.

Results:

The TKC was 1 in 7 eyes, 1 - 2 in 3 eyes, 2 in 10 eyes, 2 - 3 in 6 eyes, 3 in 8 eyes, 3 - 4 in 21 eyes, and 4 in 8 eyes. The densitometry readings were 23.29 ± 3.04 in eyes with a TKC of 1, 27.45 ± 4.00 in eyes with a TKC of 1 - 2, 24.29 ± 3.02 in eyes with a TKC of 2, 34.74 ± 23.59 in eyes with a TKC of 2 - 3, 43.78 ± 24.98 in eyes with a TKC of 3, 43.81 ± 21.38 in eyes with a TKC of 3 - 4, and 42.42 ± 26.40 in eyes with a TKC of 4. Likewise,the thinnest corneal thickness was 477.7 ± 37.6 µm, 504.7 ± 12.7 µm, 455.7 ± 44.7 µm, 428.3 ± 84.1 µm, 405.6 ± 90.7 µm, 392.4 ± 52.6 µm, and 374.1 ± 46.4 µm, respectively. Densitometry readings were positively correlated with the TKC (correlation coefficient, 0.50; p < 0.001) and negatively correlated with the thinnest corneal thickness (correlation coefficient, - 0.57; p < 0.001).

Conclusions:

The present results show that the light scattering expressed by densitometry increases according to the severity of keratoconus and probably affects the loss of visual function in eyes with progressed keratoconus. FINANCIAL INTEREST: NONE