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\begin{document}
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\title{Effect of Lens Capsular Tension Ring on Preventing Capsular Contraction
Syndrome in the Surgery of Retinitis Pigmentosa Combined with Cataract:
Retrospective Case Series}



\author[1]{Chang Xi Chen}%
\author[1]{Jin Da Wang}%
\author[1]{Jing Shang Zhang}%
\author[1]{Ying Xiong}%
\author[1]{Jing Li}%
\author[1]{Shu Ying Chen}%
\author[1]{Zhen Yu Liu}%
\author[1]{Xiu Li Sun}%
\author[1]{Yusufu  Mayinuer}%
\author[2]{Xiu Wan}%
\affil[1]{Affiliation not available}%
\affil[2]{Beijing Institute of Ophthalmology}%


\vspace{-1em}



  
  \date{April 25, 2026}


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\selectlanguage{english}
\begin{abstract}
PURPOSE: To observe the effect of phacoemulsification and intraocular
lens (IOL) implantation with or without lens capsular tension ring (CTR)
on retinitis pigmentosa (RP) combined with cataract patients. DESIGN:
Retrospective case series study. METHODS: 63 cases (84 eyes) of RP with
cataract were collected, including 30 males and 33 females.
Phacoemulsification with 3.0 mm clear corneal incision was performed in
all the patients. IOL and CTR implantation was performed in 44 eyes, and
IOL implantation alone was performed in 40 eyes. All cases were followed
up at 1 week and 1, 3, 6 months after the surgery to compare the best
corrected visual acuity (BCVA), intraocular pressure (IOP), corneal
endothelial cell count (ECC) and complications before and after the
surgery. RESULTS: All surgeries were successfully completed by the same
physician, and IOL and CTR were all implanted in capsule without
complications. The BCVA at 6 months after surgery was 0.91\selectlanguage{ngerman}±0.88 LogMAR.
It improved a little compared with the BCVA(1.3±0.7LogMAR) before
surgery and there was statistically significant difference (P=0.003).
Four cases of capsule contraction syndrome (CCS) occurred in no CTR
implantation group and there was no CCS in CTR group. There was
statistically significant difference in the incidence of CCS between two
groups(P=0.047). CONCLUSIONS: Phacoemulsification for RP combined with
cataract is safe and reliable, and CTR implantation is helpful in
reducing the complications caused by capsule contraction%
\end{abstract}\selectlanguage{ngerman}%



\sloppy


\textbf{Effect of Lens Capsular Tension Ring on Preventing Capsular
Contraction Syndrome in the Surgery of Retinitis Pigmentosa Combined
with Cataract: Retrospective Case Series}

CHEN Chang Xi\textsuperscript{1}, WANG Jin Da\textsuperscript{1}, ZHANG
Jing Shang\textsuperscript{1}, XIONG Ying\textsuperscript{2}, LI
Jing\textsuperscript{2}, CHEN Shu Ying\textsuperscript{1}, SUN Xiu
Li\textsuperscript{1}, LIU Zhen Yu\textsuperscript{1}, MAYINUER
Yusufu\textsuperscript{1}, WAN Xiu Hua\textsuperscript{1}

1. Beijing Institute of Ophthalmology, Beijing Tongren Eye Center,
Beijing Tongren Hospital of Capital Medical University; Beijing Key
Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China;

2. Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital
Medical University , Beijing Key Laboratory of Ophthalmology and Visual
Sciences, Beijing 100005, China;

Corresponding author: WAN Xiu Hua, Email: xiuhuawan@163.com

\textbf{Abstract:}

\textbf{PURPOSE:} To observe the effect of phacoemulsification and
intraocular lens (IOL) implantation with or without lens capsular
tension ring (CTR) on retinitis pigmentosa (RP) combined with cataract
patients.

\textbf{DESIGN:} Retrospective case series study.

\textbf{METHODS:} 63 cases (84 eyes) of RP with cataract were collected,
including 30 males and 33 females. Phacoemulsification with 3.0 mm clear
corneal incision was performed in all the patients. IOL and CTR
implantation was performed in 44 eyes, and IOL implantation alone was
performed in 40 eyes. All cases were followed up at 1 week and 1, 3, 6
months after the surgery to compare the best corrected visual acuity
(BCVA), intraocular pressure (IOP), corneal endothelial cell count (ECC)
and complications before and after the surgery.

\textbf{RESULTS:} All surgeries were successfully completed by the same
physician, and IOL and CTR were all implanted in capsule without
complications. The BCVA at 6 months after surgery was 0.91\selectlanguage{ngerman}±0.88 LogMAR.
It improved a little compared with the BCVA(1.3±0.7LogMAR) before
surgery and there was statistically significant difference (P=0.003).
Four cases of capsule contraction syndrome (CCS) occurred in no CTR
implantation group and there was no CCS in CTR group. There was
statistically significant difference in the incidence of CCS between two
groups(P=0.047).

\textbf{CONCLUSIONS} : Phacoemulsification for RP combined with cataract
is safe and reliable, and CTR implantation is helpful in reducing the
complications caused by capsule contraction.

\textbf{Key Words:} cataract, retinitis pigmentosa, capsular
contraction, lens capsular tension ring, complication

\textbf{What was known}

The cataract surgery of RP patients is safe and reliable and the final
postoperative vision of patients is closely related to the structure of
macular area.

\textbf{What this paper adds}

The capsule contraction of RP patients is relatively rapid after
cataract surgery. The suspensory ligament relaxation is easy to cause
CCS and dislocation of the IOL. The CTR implantation is helpful to
reduce the complications caused by capsule contraction.

\textbf{Background:}

Retinitis pigmentosa (RP) is a clinically common congenital retinal
disease, with a incidence of about 1/4000(1). The pathological
manifestations include progressive dysfunction of retinal pigment
epithelial cell and photoreceptor cell, and patients tend to have night
blindness, reduced vision field and poor vision. Currently, there is no
effective treatment or prevention measures for RP, and measures such as
stem cell transplantation and gene therapy are still in the research
stage(2). In addition to primary retinal damage, RP is usually
accompanied by other eye diseases. Cataract is the most common
complication of RP. Patients with RP complicated with cataract are young
in age and the condition progresses rapidly, which has a great impact on
the remaining vision of patients, and usually requires surgical
treatment. This paper retrospectively analyzed the vision, intraocular
pressure (IOP), corneal endothelial cell count (ECC), macular morphology
and postoperative complications of 63 patients (84 eyes) who underwent
phacoemulsification and intraocular lens (IOL) implantation in our
hospital from January 2014 to October 2019. The results are as follows.

\textbf{Methods}

\textbf{Subjects}

The study complied with the tenets of the Declaration of Helsinki and
was approved by the Ethics Board of the Beijing Tongren Hospital.
Written informed consent was obtained from all patients before surgery.
A total of 63 cases (84 eyes) of RP combined with cataract treated in
our hospital from January 2014 to October 2019 were collected, including
30 males and 33 females, aged 35-58 years, with an average age of 42.8
years. Phacoemulsification with a 3.0mm clear corneal incision was
performed in all the patients. IOL and capsular tension ring (CTR)
implantation was performed in 44 eyes and IOL implantation alone was
performed in 40 eyes. All the collected cases were RP patients with
cataract, no other eye diseases, no history of eye surgery or trauma.

\textbf{Examinations}

Before surgery, all the enrolled patients were examined by slit lamp,
IOP and corneal (ECC) were measured. All patients were taken refractive
examination and the best corrected visual acuity (BCVA) was determined.
Corneal curvature was determined by keratometer, and A and B
ultrasonography were performed to determine the axial length of the eye.
The SRK-T formula was used to calculate the IOL degree. Fundus photos
were taken and optical coherence tomography (OCT) was used to examine
fundus conditions. Follow-up visits were performed 1 week, 1 month, 3
months and 6 months after the operation, and all preoperative
examinations were also performed to evaluate postoperative recovery and
complications.

\textbf{Surgery}

The same surgeon (Wan Xiu Hua) performed standard phacoemulsification
and IOL implantation in all cases. One hour before the operation,
tropicamide eye drops were applied to ensure the pupil dilation and
ciliary muscle relaxation during the operation. The conjunctival sac was
anesthetized twice within 5-10 minutes before surgery. A 3.0mm corneal
incision was made in the transparent area of the limbal cornea between 9
to 12 points and an auxiliary incision was made at 2 points of the
corneal limbus. The viscoelastic agent was injected into the anterior
chamber. Continuous circular capsulorhexis was performed, and water
separation nucleus and surrounding cortex appeared to the ''golden
ring''. Phacoemulsification removed lens nuclear and removed cortex. The
anterior chamber and capsule were filled with viscoelastic agent. The
CTR and IOL were implanted through 3.0mm incision. The viscoelastic
agent was removed from the anterior chamber and the incision was made
watertight.

\textbf{Statistical analysis}

Statistical analysis was performed using SPSS for Windows (version 22.0;
IBM-SPSS, Chicago, IL, USA). Paired t-test was used to compare
preoperative and postoperative BCVA, IOP, and corneal ECC. The
independent sample t test and the chi-square test were used to compare
the two groups. P-values represent results for 2- sided tests, with
values less than 0.05 considered statistically significant.

\textbf{Results}

All operations were successfully completed by the same physician, and
IOL and CTR were all implanted in capsule without intraoperative
complications.

The data of preoperative and postoperative BCVA, IOP, and corneal ECC
were showed in table 1. The BCVA at 6 months after surgery was 0.91±0.88
LogMAR. It improved a little compared with the BCVA before
surgery(1.3±0.7LogMAR), and there was a statistically significant
difference (P=0.003). The visual acuity was significantly improved in 22
eyes, slightly improved in 20 eyes, and no significant improvement in
the remaining eyes. The IOP was higher and the corneal ECC was less at 6
months after surgery compared with the data before surgery, and there
were also statistically significant differences (P=0.000). However, they
were both in the normal range. OCT examination showed no change of
macular morphology before and after surgery.

\textbf{Postoperative complications}

There were four cases of capsule contraction syndrome (CCS) (Fig.1) in
the group without CTR implantation at 6 months after surgery and there
was no CCS in CTR group. There was statistically significant difference
in the incidence of CCS between two groups(P=0.047). There were no
statistically significant differences in other conditions between the
two groups (table 2). All CCS cases were cured through capsule loosening
surgery.

\textbf{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.

\textbf{Financial Disclosure}

No authors have a financial and proprietary interest in any material and
method mentioned.

\textbf{Data Availability Statement}

All the data in the manuscript can be found in the medical record room
of Beijing Tongren Hospital.

\textbf{References}

1 Verbakel SK, van Huet R, Boon C et al. Non-syndromic retinitis
pigmentosa. \emph{Prog Retin Eye Res} 2018;\textbf{66} :157-86.

2 Huang Y, Enzmann V, Ildstad ST. Stem cell-based therapeutic
applications in retinal degenerative diseases. \emph{Stem Cell
Rev}2011;\textbf{7} :434-45.

3 Auffarth GU, Tetz MR, Krastel H, Blankenagel A, Völcker HE.
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4 Chan T, Lam SC, Mohamed S, Wong R. Survival analysis of visual
improvement after cataract surgery in advanced retinitis
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5 Davies EC, Pineda R. Cataract surgery outcomes and complications in
retinal dystrophy patients. \emph{Can J Ophthalmol}2017;\textbf{52}
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6 De Rojas JO, Schuerch K, Mathews PM et al. Evaluating Structural
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8 Nakamura Y, Mitamura Y, Hagiwara A et al. Relationship between retinal
microstructures and visual acuity after cataract surgery in patients
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9 Sandberg MA, Brockhurst RJ, Gaudio AR, Berson EL. The association
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10 Yoshida N, Ikeda Y, Murakami Y et al. Factors affecting visual acuity
after cataract surgery in patients with retinitis
pigmentosa.\emph{Ophthalmology} 2015;\textbf{122} :903-8.

11 Ascaso FJ, Huerva V, Grzybowski A. Epidemiology, Etiology, and
Prevention of Late IOL-Capsular Bag Complex Dislocation: Review of the
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12 Bayyoud T, Bartz-Schmidt KU, Yoeruek E. Long-term clinical results
after cataract surgery with and without capsular tension ring in
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Figure legend

Figure 1: The cases of the lens' capsule contraction syndrome(CCS): The
anterior capsule membrane was obviously wrinkled and opaque, and the
capsule mouth was narrowed and offset .\selectlanguage{english}
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\includegraphics[width=0.70\columnwidth]{figures/Figure1/Figure1}

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