[Correlations between retinal thickness analyzer (RTA) and confocal scanning laser tomography (HRT) in optic disc analysis].
OBJECTIVE
To determine if the measures obtained in an optic disc study using the retinal thickness analyzer (RTA) can be adequately correlated with values provided by the confocal scanning laser Heidelberg Retina Tomograph (HRT).


METHODS
We analyzed 20 eyes of 20 normal subjects. The contours of the optic disc were drawn by a single operator using both instruments. The data compared were the values of 10 variables denoted in the same way by each instrument and these provided information on disc and cup morphology.


RESULTS
Of the 10 variables, only the following three showed clear correlation between the two instruments: maximum cup depth (r=0.926, p=0.001), mean cup depth (r=0.857, p=0.001) and cup shape measure (CSM, r=0.672, p=0.002). The correlation shown by the remaining variables ranged from 0.001 (cup area) and 0.488 (cup volume).


CONCLUSIONS
The variables showing best correlation between instruments were those providing information on cup morphology. Operator subjectivity when drawing the disc contour using each device could account for the lower incidence of correlation of the other variables examined.
Martínez de la Casa
J M
JM
Hospital Clínico San Carlos, Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Madrid, España. martinezcasa@jazzfree.com
García Feijoó
J
J
Castillo Gómez
A
A
García Sánchez
J
J
D000328:Adult; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007368:Interferometry / Q000379:methods; D007834:Lasers; D008297:Male; D009898:Optic Disk / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D012160:Retina / Q000033:anatomy & histology; D014054:Tomography / Q000379:methods*