Corneal biomechanical properties in normal, regular astigmatic, and keratoconic eyes
2011
PURPOSE: To compare the biomechanical properties of normal, regular astigmatic, and
keratoconic corneas.
METHODS: Corneal hysteresis (CH), corneal resistance factor (CRF), central corneal
thickness (CCT), Goldmann correlated intraocular pressure (IOPg) and corneal compensated
IOP (IOPcc) were measured with the ocular response analyzer (ORA) in 93 normal,
56 astigmatic, and 39 keratoconic eyes.
RESULTS: Mean astigmatism values were 0.50, 3.76, and 5.29 diopters in control, astigmatic
and keratoconic group, respectively. Mean CH was significantly lower in keratoconic
(7.9±1.4 mmHg) than in control (10.7±1.3 mmHg) and astigmatic (10.5±1.8 mmHg)
eyes. Mean CRF was 7.1±1.7 mmHg in keratoconic group, 10.5±1.3 mmHg in control
group, and 10.5±2.1 mmHg in astigmatic group. Both differences were statistically significant
(p=0.0001). CCT was lower in keratoconus (463.3±42.7 µm) than in control
(554.0±28.5 µm; p=0.0001), and astigmatic eyes (556.2±39.9 µm; p=0.0001). IOPg in
keratoconic eyes (11.2±3.5 mmHg) was lower than in the control (14.8±2.4 mmHg;
p=0.0001) and astigmatic group (15.5±3.8 mmHg; p=0.0001). No significant differences
of IOPcc were present among the three groups (p=0.239). Mean CH-CRF was higher in
keratoconic (0.9±1.0 mmHg) than in normal (0.2±0.7 mmHg; p=0.011) and astigmatic
eyes (0.0±1.1 mmHg; p=0.0001). CONCLUSIONS. Keratoconic eyes, unlike astigmatic
and normal eyes, have different corneal biomechanical properties. ORA may be a useful
technique for the differential diagnosis between regular astigmatism and astigmatism
caused by keratoconus.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
24
References
11
Citations
NaN
KQI