Kajal Seema S.1, Manasa S.2, Prasenna M.3, Kavitha S.4
BACKGROUND
Refractive status of the eye depends on the balance between multiple factors such
as corneal power, lens power, anterior chamber depth and axial length.
Compensatory adjustments between the axial length and the keratometry of the
cornea play an important role in emmetropisation. Capturing the biometric
measurements of the eye is an important part of the preoperative work up of
patients to calculate the intraocular lens (IOL) power, hence, the importance of
better understanding of the interplay between the biometry parameters. Our aim
was to assess the variation of keratometry with the refractive status and axial
length of the eye.
METHODS
This is a cross sectional observational study of 299 eyes that were operated for
cataract surgery from July 2018 to December 2018 at a tertiary care centre in
South India. Axial length and central corneal curvature were measured and
average was taken for analysis. Eyes with axial length ≤ 22 mm were grouped as
hyperopic (Group 1), those with axial length between 22.0 mm and 24.0 mm were
grouped as normal (Group 2) and eyes with axial length more than 24.0 mm were
grouped as myopic (Group 3). The distribution of corneal curvature, AL / K ratio
and IOL power across different ranges of axial length was assessed.
RESULTS
There was a statistically significant flattening of cornea with increase in axial length
(P < 0.001). Distribution of axial length to corneal radius of curvature was also
found to be statistically significant (P < 0.001) among the three groups.
CONCLUSIONS
With an increase in axial length there was a statistically significant progressive
flattening of cornea. The AL / K ratio can be a better measure of the refractive
status of an individual than axial length alone.
