Outcomes of 3 Incision-size-dependent Phacoemulsification Systems

Completed

Conditions: Cataract

Interventions: Procedure: phacoemulsification

Registration Number: NCT01429532

Lead Sponsor: Sun Yat-sen University

Brief Summary: The purpose of this study is to compare the outcomes of cataract surgery performed with three incision-size-dependent phacoemulsification systems (1.8, 2.2 and 3.0 mm).

Detailed Description: It is generally the case that smaller corneal cataract surgical incisions are associated with more rapid wound healing, more stable corneal biomechanical properties and less surgically induced astigmatism (SIA). With the development of phacoemulsification and foldable intraocular lenses (IOL) during recent decades, the size of clear corneal incisions has been reduced from 3.2-mm (coaxial small incision) to 1.4-mm (bimanual micro incision). Micro incision cataract surgery (MICS), including bimanual and micro coaxial phacoemulsification, has attracted much interest recently, due to its safety and ease of learning. However, the superiority of coaxial micro incision cataract surgery as compared conventional coaxial cataract surgery is still not certain, because micro incision phacoemulsification may result in longer ultrasound time (UST), the use of more ultrasonic power and consequently higher endothelial cell loss (ECL).

In our previous studies of the OZil Torsional phacoemulsification system (Infinity, Alcon), we reported that the safety and effectiveness of cataract surgery are influenced by many factors, including the blade used to create the incision, the phacoemulsification apparatus, and the IOL and mode of IOL delivery, which together constitute a surgical system, whose outcomes are restricted by the best performance of each component. Today, micro coaxial phacoemulsification is in wide use for cataract surgery, but the lower limits of incision size should be understood in the context of the various components of the surgical system.

In this study, we compared the safety and efficacy of three different incision-size-dependent phacoemulsification systems, 1.8, 2.2 and 3.0 mm, and evaluated the relationship between incision size and SIA.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 120

Inclusion Criteria

age between 55 and 85 years
the presence of nuclear or cortex-nuclear cataract, grades 2.0 to 4.0 (Lens Opacities Classification System III)
a transparent central cornea
pupil dilating to >= 7 mm at the time of preoperative examination
a preoperative central endothelial cell count of >= 1500 cells per square millimeter

Exclusion Criteria

previous intraocular surgery
glaucoma
pseudoexfoliation
uveitis
high myopia
diabetes mellitus

Study & Design

Study Type: OBSERVATIONAL

Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Group II	phacoemulsification	2.2-mm-incision-size phacoemulsification system
Group I	phacoemulsification	1.8-mm-incision-size phacoemulsification system
Group III	phacoemulsification	3.0-mm-incision-size phacoemulsification system

Primary Outcome Measures

Name	Time	Method
Central Cornea Endothelial Cell Loss	post-operative week 1, post-operative month 1, and post-operative month 3	Central cornea endothelial cell loss was calculated on the basis of preoperative and postoperative endothelial cell density.
Surgically Induced Astigmatism	post-operative week 1, post-operative month 1, and post-operative month 3	Corneal astigmatism was measured using an eye scanner (Pentacam; Oculus, Wetzlar, Germany), and the SIA was calculated at each postoperative visit using the following equation.

Secondary Outcome Measures

Name	Time	Method
Best-corrected Visual Acuity	post-operative week 1, post-operative month 1, and post-operative month 3	The best-corrected visual acuity (BCVA) was measured, using an ETDRS chart and auto-refraction as refined by an ophthalmologist, preoperatively and at postoperative 1 day, 1 week, 1 month and 3 months.