Dr. Hardten et al., CLINICAL AND ANATOMICAL STUDY OF THE EFFECT OF TRANSSCLERAL FIXATION OF POSTERIOR CHAMBER LENSES ON EARLY POSTKERATOPLASTY ASTIGMATISM, Cornea, 12(4), 1993, pp. 282-288
We reviewed the pattern of astigmatism after penetrating keratoplasty
and transsclerally sutured posterior chamber lens (TSPCL) placement in
73 patients. Thirty-five patients (48%) had an axis of astigmatism or
iented perpendicularly to the haptics of the TSPCL. Twenty-seven patie
nts (37%) had an orientation of astigmatism that was in the same merid
ian as the haptics of the TSPCL. Eleven patients (15%) had an axis of
astigmatism oriented obliquely to the meridian of the haptics of the T
SPCL. The distance the haptic fixation sutures were placed behind the
limbus appeared to be correlated with the orientation of astigmatism.
Patients having the lens fixated within 0.75 mm of the limbus were mor
e likely to have astigmatism oriented perpendicular to the meridian of
the haptics of the posterior chamber lens in the early postoperative
period. Patients having the lens fixated 2-3 mm posterior to the limbu
s were more likely to have astigmatism oriented in the same meridian a
s the haptics of the posterior chamber lens in the early postoperative
period. In an eye bank model of TSPCLs during penetrating keratoplast
y, the placement of a posterior chamber lens with haptics fixated with
in 0.75 mm of the limbus significantly widens the recipient bed an ave
rage of 0.3 mm in the meridian of the haptics of lens placement (p = 0
.02). When the posterior chamber lens haptics were fixated 3 mm poster
ior to the limbus, the recipient bed was significantly narrowed in the
meridian of lens placement an average of 0.2 mm (p = 0.02). It appear
s that the TSPCLs may have an effect on early postkeratoplasty astigma
tism by distorting the corneal wound at the time of keratoplasty.