Plain English Summary
Background and study aims
A cataract is a clouding of the lens in the eye which decreases vision. It is estimated that 25% to 40% of cataract patients have astigmatism, a focusing disorder of the eye that distorts vision. During cataract surgery toric intraocular lenses (IOLs) can be implanted inside the eye to replace the eye's natural lens and correct astigmatism. In the standard procedure, ophthalmic viscosurgical devices (OVD) are solutions used during implantation of IOLs to create and maintain space in the eye. Hydroimplantation is a technique for implantation of a foldable IOL without an OVD. The aim of this study is to compare the OVD and hydroimplantation techniques for the implantation of a toric IOL.
Who can participate?
Patients with cataract and regular astigmatism between 1.0 and 3.0 diopters (D)
What does the study involve?
Participants undergo phacoemulsification (cataract removal) and are randomly allocated to undergo implantation of toric IOLs with either the OVD technique or the hydroimplantation technique. In the OVD group, the toric IOLs are implanted with OVD. In the hydroimplantation group, balanced salt solution (BSS) is used instead of OVD during implantation of toric IOLs. The eyes are examined at 2 hours, 1 day, 1 week, 1 month, and 3 months after surgery.
What are the possible benefits and risks of participating?
The hydroimplantation technique provides similar visual outcomes to the conventional technique using OVDs for the implantation of toric IOLs, but it has the advantage of increased efficiency, reduced surgical time and cost, and does not cause high intraocular pressure. The hydroimplantation technique is also useful for the alignment of the toric IOLs during the surgery. However, this technique is only recommended for experienced surgeons, and may cause complications for novice ophthalmologists.
Where is the study run from?
Jinling Hospital (China)
When is study starting and how long is it expected to run for?
January 2012 to December 2014
Who is funding the study?
Jinling Hospital (China)
Who is the main contact?
Dr Zhenping Huang
Comparison of two techniques for toric intraocular lens implantation: hydroimplantation versus ophthalmic viscosurgical devices
In this study, patients with cataract and preexisting regular corneal astigmatism between 1.0 and 3.0 diopters (D) underwent phacoemulcification and implantation of toric IOLs with the ophthalmic viscosurgical device (OVD) technique or hydroimplantation technique.
The aim of this study was to evaluate and compare the clinical results between the OVD group and the hydroimplantation group for the implantation of a single-piece, acrylic foldable toric IOL. In the OVD group, the toric IOLs were implanted with OVD. In the hydroimplantation group, balanced salt solution (BSS) was used instead of OVD during implantation of toric IOLs.
It is hypothesized that the hydroimplantation technique will provides comparable visual outcomes to the OVD technique for the implantation of toric IOLs but with increased efficiency, reduced surgical time and cost, and no concerns of OVD-induced elevated IOP.
Ethical Committee of Jinling Hospital, 25/08/2011, ref: 2011NLY-027
Prospective interventional single-center study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
No participant information sheet available
Eyes with cataract and preexisting regular corneal astigmatism between 1.0 and 3.0 diopters (D)
60 eyes with cataract and preexisting regular corneal astigmatism underwent phacoemulsification and AcrySof toric IOLs implantation, and the eyes were randomized to undergo either the OVD technique or the hydroimplantation technique.
Primary outcome measure
1. Postoperative IOP is measured using the Computerized Tonometer at 2 hours, 1 day, 1 week, 1 month, and 3 months after surgery
2. Postoperative UDVA is measured using Snellen or “E” chart 3 months after surgery
3. ECD is measured using SP-3000P, Topcon Corp. Tokyo, Japan at 3 months after surgery
4. Refractive astigmatism is measured using keratometry: IOLMaster at 3 months after surgery
5. IOL rotation is measured using a slit lamp at 3 months after surgery
6. Time taken for IOL implantation is measured using records at time of surgery
Secondary outcome measures
Astigmatism vector analysis is measured using Thibos and Horner’s power vector notation at 3 months after surgery
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Age-related cataract with preoperative corneal astigmatism between 1.0 and 3.0 D and nucleus sclerosis up to grade 3
2. 40-90 years old
Target number of participants
Participant exclusion criteria
1. Patients with history of previous ocular surgery
2. Pupil size less than 7.5 mm after dilatation
3. Anterior chamber less than 2.25 mm
4. Compromised endothelial cell functio
5. Corneal disorder
6. Complicated cataract
9. Severe myopia
10. Diabetic retinopathy
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
305 East Zhongshan Road
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The manuscript is under minor revision with BMC Ophthalmology.
IPD sharing statement
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Yueqin Chen.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)