Clinical trial NCT01429532: Outcomes of 3 Incision-size-dependent Phacoemulsification Systems
Official title: Clinical Evaluation of Three Incision-size-dependent Phacoemulsification Systems
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Cataract
Keywords: Cataract
Lead sponsor: Sun Yat-sen University
Sponsor class: OTHER
Collaborators: name: Ministry of Health, China
name: National Natural Science Foundation of China
First posted: 2011-09-07
Enrollment: 120
Sex: ALL
Minimum age (years): 55
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: This prospective randomized study comprised 120 patients (120 eyes) with age-related cataract enrolled for surgeries between July 2010 and January 2011 at the Zhongshan Ophthalmic Center, Guangzhou, China.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Central Cornea Endothelial Cell Loss
timeFrame: post-operative week 1, post-operative month 1, and post-operative month 3
measure: Surgically Induced Astigmatism
timeFrame: post-operative week 1, post-operative month 1, and post-operative month 3
Secondary outcomes:
measure: Best-corrected Visual Acuity
timeFrame: post-operative week 1, post-operative month 1, and post-operative month 3
Other outcomes:
Locations:
city: Guangzhou
country: China
facility: Zhongshan Ophthalmic Center, Sun Yat-sen U
state: Guangdong
Study officials:
affiliation: Sun Yat-sen University
name: Yizhi Liu, M.D.,Ph.D.
role: STUDY_DIRECTOR
References:
citation: Weikert MP. Update on bimanual microincisional cataract surgery. Curr Opin Ophthalmol. 2006 Feb;17(1):62-7. doi: 10.1097/01.icu.0000193069.32369.e1.
citation: Alio JL, Agdeppa MC, Rodriguez-Prats JL, Amparo F, Pinero DP. Factors influencing corneal biomechanical changes after microincision cataract surgery and standard coaxial phacoemulsification. J Cataract Refract Surg. 2010 Jun;36(6):890-7. doi: 10.1016/j.jcrs.2009.12.041.
citation: Elkady B, Pinero D, Alio JL. Corneal incision quality: microincision cataract surgery versus microcoaxial phacoemulsification. J Cataract Refract Surg. 2009 Mar;35(3):466-74. doi: 10.1016/j.jcrs.2008.11.047.
citation: Liu Y, Jiang Y, Wu M, Liu Y, Zhang T. Bimanual microincision phacoemulsification in treating hard cataracts using different power modes. Clin Exp Ophthalmol. 2008 Jul;36(5):426-30.
citation: Liu Y, Zeng M, Liu X, Luo L, Yuan Z, Xia Y, Zeng Y. Torsional mode versus conventional ultrasound mode phacoemulsification: randomized comparative clinical study. J Cataract Refract Surg. 2007 Feb;33(2):287-92. doi: 10.1016/j.jcrs.2006.10.044.
citation: Zeng M, Liu X, Liu Y, Xia Y, Luo L, Yuan Z, Zeng Y, Liu Y. Torsional ultrasound modality for hard nucleus phacoemulsification cataract extraction. Br J Ophthalmol. 2008 Aug;92(8):1092-6. doi: 10.1136/bjo.2007.128504. Epub 2008 Jun 20.
citation: Wang Y, Xia Y, Zeng M, Liu X, Luo L, Chen B, Liu Y, Liu Y. Torsional ultrasound efficiency under different vacuum levels in different degrees of nuclear cataract. J Cataract Refract Surg. 2009 Nov;35(11):1941-5. doi: 10.1016/j.jcrs.2009.05.055.
citation: Xia Y, Liu X, Luo L, Zeng Y, Cai X, Zeng M, Liu Y. Early changes in clear cornea incision after phacoemulsification: an anterior segment optical coherence tomography study. Acta Ophthalmol. 2009 Nov;87(7):764-8. doi: 10.1111/j.1755-3768.2008.01333.x. Epub 2009 Jun 22.
citation: Luo L, Lin H, He M, Congdon N, Yang Y, Liu Y. Clinical evaluation of three incision size-dependent phacoemulsification systems. Am J Ophthalmol. 2012 May;153(5):831-839.e2. doi: 10.1016/j.ajo.2011.10.034. Epub 2012 Feb 4.