Study design :
A prospective, observational, and
controlled study.
Purpose:
To evaluate the long-term effects
of the soft contact lens (CL) on corneal
curvature, corneal surface regularity,
corneal thickness , corneal endothelium
and tear break-up time in
mild-moderate
myopia comparing to
the
non-contact lens users myopic
eyes,
and to estimate the refractive
and
topographic alterations in myopic
contact lens users (CLU) after two
weeks
cessation of wearing.
Methods:
The changes in topography, and
pachymetry, corneal endothelium, and TBUT were assessed in CLU
group. The first pentacam evaluation
was done within one day after CL removal
(first visit) and then the second
examination after two weeks
from
the cessation of CL (second
visit).
The topographical indices included
keratometry readings in the
flattest
(K1), steepest meridians
(K2),
anterior maximum K reading (K
max),
minimum K reading (K min),
Index
of Surface Variance (ISV), keratoconus
index (KI), central and thinnest
corneal thickness, endothelial
count,
Coefficient of variation (CV)
and
hexagonal % were recorded
each
visit.
Results:
Following 2 weeks discontinua-
tion of soft CL, changes in K read- ings, endothelial count, CV, hexagonal
% seemed to be reversible, nevertheless,
the changes in corneal
thickness
and TBUT appeared to require
more time for resolving. Conclusions:
Soft CL use is contributing to clinically substantial changes in topographical
corneal parameters, corneal
thickness, endothelial count,
and
TBUT. After 2 weeks of wearing
discontinuations,
these changes
were
reversible except corneal thickness
and TBUT, which may need a
longer
time for recovery