Effect of pathological myopia on biomechanical properties: a study by ocular response analyzer.
OBJECTIVE
To evaluate the ocular response analyzer (ORA) measurements of patients with pathological myopia in comparison with those of emmetropic control subjects, and to investigate the correlation between these ORA measurements and spherical equivalent (SE).


METHODS
Measurements of 53 eyes of 53 subjects with pathological myopia (SE>-6.00 D) were compared with those of 60 eyes of 60 emmetropic controls. Corneal hysteresis (CH), corneal resistance factor (CRF), noncontact tonometer intraocular pressure (IOPg), and corneal-compensated IOP (IOPcc) were obtained for each subject. The refractive error value was determined as SE via a cycloplegic refraction test.


RESULTS
The mean age was 54.1±18.9y (ranging from 5 to 88) in the pathological myopic group and 56.2±19.0y (ranging from 6 to 89) in the control group. There were no significant differences between the groups concerning age and sex. CH and CRF were significantly lower in the pathological myopic group than in the control group (P<0.001, P=0.005, respectively). IOPcc and IOPg were significantly higher in the pathological myopic group than in the control group (P<0.001, P=0.009, respectively). There were significantly positive correlations between CH and SE (r=0.565, P<0.001) and between CRF and SE (r=0.364, P=0.007). There were significantly negative correlations between IOPcc and SE (r=-0.432, P=0.001) and between IOPg and SE (r=-0.401, P=0.003).


CONCLUSIONS
The present study displayed that pathological myopia affected biomechanical properties measured by ORA. The results of corneal biomechanical properties measured by ORA may need to be appreciated by taking refraction into account. Further, pathological myopia might be related with the increased IOP.
Department of Ophthalmology, Recep Tayyip Erdoğan University Medical School, Rize 53100, Turkey.
Veysi
V
Öner
Department of Ophthalmology, Malatya State Hospital, Malatya 44000, Turkey.
Mehmet
M
Taş
Department of Ophthalmology, Malatya State Hospital, Malatya 44000, Turkey.
Erdal
E
Özkaya
Department of Ophthalmology, Recep Tayyip Erdoğan University Education and Research Hospital, Rize 53100, Turkey.
Yavuz
Y
Oruç
corneal hysteresis; corneal resistance factor; intraocular pressure; ocular response analyzer; pathological myopia