Discussion
RP is a common hereditary eye disease and most RP patients are
complicated with cataract. The lens opacification often occurs in the
central of posterior capsule or posterior polar cortex(3), which
seriously affects the residual tubular vision. For patients with RP
complicated with cataract, current studies have proved that most
patients have improved visual acuity and visual field after surgery(4),
and the effect is clear. Cataract surgery itself is safe and reliable,
and does not lead to the occurrence and progress of other RP related
complications. Therefore, it is suggested that RP complicated with
cataract should be treated by surgery(5-7). The results of this study
also showed that vision was improved in most patients, the operation
effect was good, and the operation was safe and reliable.
Most studies have reported that the final postoperative vision of
patients is closely related to the structure of macular area(8, 9). In
this study, it was also found that the visual acuity of patients with
relatively healthy macular before surgery was significantly improved,
while the improvement in visual acuity of patients with significantly
thinner macular was limited. This also suggests that for RP patients
with cataract, preoperative OCT examination is very important for the
prediction of postoperative vision(10).
Due to the common lens suspensory ligament relaxation in RP patients
with cataract, it is necessary to pay attention to the prevention and
treatment of capsule tear, suspensory ligament rupture and other related
intraoperative complications. The capsule contraction of such patients
is relatively rapid after surgery. The suspensory ligament relaxation
tends to cause CCS and dislocation of the IOL(11). In this study, four
cases of CCS occurred in patients without CTR implantation, and were
treated with capsule loosening operation at six months after the
cataract surgery. There was no CCS among CTR implanted patients. Bayyoud
T, etc(12). reported that there were 52 eyes of RP with cataract surgery
patients. Two cases of CCS happened in no implanted CTR group, while
there no CCS occurred in implanted CTR group after a median follow-up of
26 months, and the incidence was 4%. It also suggested that CTR
implantation can help to reduce the postoperative CCS in RP with
cataract surgery. In addition, patients with RP complicated with
cataract are relatively young in age, and posterior capsular opacity
(PCO) occurs quickly, which requires timely treatment. CTR implantation
also has certain effects on the prevention of PCO(12).
The results of this study showed that IOP was higher and corneal ECC was
less after surgery. Though they were in normal range, it indicated that
attention should be paied to the IOP and ECC in RP with cataract
surgery. There were some reports on the occurrence of the postoperative
macular edema in RP with cataract surgery(5, 12). However, it was not
found in the current study. The occurrence of postoperative macular
edema of cataract surgery associated with many factors. The visual
acuity of RP patients was poor due to the severe retinopathy before
surgery, and macular edema after surgery would further compromise the
vision. Hence, it is crucial to carry out postoperative OCT examination
regularly.