1 research outputs found
In-vivo corneal biomechanical analysis of unilateral keratoconus
AIM: To evaluate and compare corneal biomechanical findings measured by
ocular response analyzer, topographic and pachymetric findings in
patients with unilateral keratoconus patients and healthy controls.
METHODS: This is an observational, case -control study. Patients with
keratoconus in one eye and forme fruste keratoconus in the fellow eye
were compared with sex and age matched with controls healthy subjects.
All subjects were evaluated with rotating scheimpflug imaging system.
The receiver -operating -characteristic curves were analyzed to evaluate
the sensitivity and specificity of the parameters.
RESULTS: Twenty-seven patients with keratoconus in one eye and forme
fruste keratoconus in the fellow eye were compared with 40 eyes of 40
normal subjects. Corneal hysteresis (CH) was 8.0 +/- 1.7 mm Hg in
keratoconus group, 8.3 +/- 1.6 mm Hg in forme fruste keratoconus group,
and 9.8 +/- 1.6 mm Hg in control groups (P=0.54 between keratoconus and
forme fruste keratoconus groups, P<0.01 between control group and other
groups). Corneal resistance factor (CRF) was 7.1 +/- 2.2 mm Hg in
keratoconus group, 7.8 +/- 1.2 mm Hg in forme fruste keratoconus group
and 9.9 +/- 1.5 mm Hg in control group (P < 0.001 between control group
and other groups). Using receiver-operating-characteristic analysis, the
area under curve values of the parameters to distinguish forme fruste
keratoconus from control subjects were: CH (0.768), CRF (0.866). Best
cut-off points were 9.3 mm Hg and 8.8 mm Hg for CH and CRF respectively.
CONCLUSION: Ocular response analyzer parameters (CH and CRF) are found
to be significantly lower in forme fruste keratoconus patients compared
to normal control subjects