Cataract
Conditions
Keywords
Cataract
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.
Interventions
PROCEDUREphacoemulsification
Cataract surgery performed with three incision-size-dependent phacoemulsification systems (1.8, 2.2 and 3.0 mm)
Sponsors
Ministry of Health, China
National Natural Science Foundation of China
Sun Yat-sen University
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
55 Years to 85 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
China
Participant flow
Recruitment details
This prospective randomized study included 120 patients (120 eyes) with age-related cataract enrolled between July 2010 and January 2011 at the Zhong-shan Ophthalmic Center, Guangzhou, China.
Pre-assignment details
Potential subjects with previous intraocular surgery, glaucoma, pseudoexfoliation, uveitis, high myopia and diabetes mellitus were excluded from participation in the study.
Participants by arm
| Arm | Count |
|---|---|
| Group I 1.8-mm-incision-size phacoemulsification system | 40 |
| Group II 2.2-mm-incision-size phacoemulsification system | 40 |
| Group III 3.0-mm-incision-size phacoemulsification system | 40 |
| Total | 120 |
Baseline characteristics
| Characteristic | Group III | Group II | Group I | Total |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 28 Participants | 28 Participants | 28 Participants | 84 Participants |
| Age, Categorical Between 18 and 65 years | 12 Participants | 12 Participants | 12 Participants | 36 Participants |
| Age, Continuous | 72.48 years STANDARD_DEVIATION 6.15 | 71.37 years STANDARD_DEVIATION 7.19 | 73.95 years STANDARD_DEVIATION 6.05 | 72.59 years STANDARD_DEVIATION 6.32 |
| Region of Enrollment China | 40 participants | 40 participants | 40 participants | 120 participants |
| Sex: Female, Male Female | 21 Participants | 22 Participants | 19 Participants | 62 Participants |
| Sex: Female, Male Male | 19 Participants | 18 Participants | 21 Participants | 58 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 0 | 0 / 0 | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 | 0 / 0 | 0 / 0 |
Outcome results
Primary
Central Cornea Endothelial Cell Loss
Central cornea endothelial cell loss was calculated on the basis of preoperative and postoperative endothelial cell density.
Time frame: post-operative week 1, post-operative month 1, and post-operative month 3
Population: The SPSS software package (version 17.0, SPSS Inc, Chicago, IL, USA) was used for statistical analysis and sample size calculation. Mean ultrasound time (UST), surgical time, cumulative dissipated energy (CDE), total BSS volume, and SIA were compared using multifactor analysis of variance.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Group I | Central Cornea Endothelial Cell Loss | Post-op 1 w | 7.77 % of endothelial cell loss | Standard Deviation 3.76 |
| Group I | Central Cornea Endothelial Cell Loss | Post-op 1m | 11.78 % of endothelial cell loss | Standard Deviation 7.27 |
| Group I | Central Cornea Endothelial Cell Loss | Post-op 3 month | 17.83 % of endothelial cell loss | Standard Deviation 5.65 |
| Group II | Central Cornea Endothelial Cell Loss | Post-op 1 w | 9.35 % of endothelial cell loss | Standard Deviation 4.69 |
| Group II | Central Cornea Endothelial Cell Loss | Post-op 1m | 13.03 % of endothelial cell loss | Standard Deviation 8.33 |
| Group II | Central Cornea Endothelial Cell Loss | Post-op 3 month | 18.08 % of endothelial cell loss | Standard Deviation 7.93 |
| Group III | Central Cornea Endothelial Cell Loss | Post-op 1m | 12.05 % of endothelial cell loss | Standard Deviation 9.31 |
| Group III | Central Cornea Endothelial Cell Loss | Post-op 3 month | 17.66 % of endothelial cell loss | Standard Deviation 5.26 |
| Group III | Central Cornea Endothelial Cell Loss | Post-op 1 w | 7.93 % of endothelial cell loss | Standard Deviation 3.67 |
Primary
Surgically Induced Astigmatism
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.
Time frame: post-operative week 1, post-operative month 1, and post-operative month 3
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Group I | Surgically Induced Astigmatism | Post-op 1 day | 1.2 Diopters | Standard Deviation 0.32 |
| Group I | Surgically Induced Astigmatism | Post-op 1 week | 0.61 Diopters | Standard Deviation 0.24 |
| Group I | Surgically Induced Astigmatism | Post-op 1 month | 0.4 Diopters | Standard Deviation 0.21 |
| Group I | Surgically Induced Astigmatism | Post-op 3 months | 0.26 Diopters | Standard Deviation 0.18 |
| Group II | Surgically Induced Astigmatism | Post-op 3 months | 0.31 Diopters | Standard Deviation 0.19 |
| Group II | Surgically Induced Astigmatism | Post-op 1 day | 0.91 Diopters | Standard Deviation 0.34 |
| Group II | Surgically Induced Astigmatism | Post-op 1 month | 0.46 Diopters | Standard Deviation 0.24 |
| Group II | Surgically Induced Astigmatism | Post-op 1 week | 0.74 Diopters | Standard Deviation 0.25 |
| Group III | Surgically Induced Astigmatism | Post-op 3 months | 0.66 Diopters | Standard Deviation 0.21 |
| Group III | Surgically Induced Astigmatism | Post-op 1 week | 0.79 Diopters | Standard Deviation 0.23 |
| Group III | Surgically Induced Astigmatism | Post-op 1 month | 0.75 Diopters | Standard Deviation 0.31 |
| Group III | Surgically Induced Astigmatism | Post-op 1 day | 0.951 Diopters | Standard Deviation 0.28 |
Secondary
Best-corrected Visual Acuity
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.
Time frame: post-operative week 1, post-operative month 1, and post-operative month 3
Population: The SPSS software package (version 17.0, SPSS Inc, Chicago, IL, USA) was used for statistical analysis.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Group I | Best-corrected Visual Acuity | Pre-op 1 day | 0.16 logMAR | Standard Deviation 0.1 |
| Group I | Best-corrected Visual Acuity | Post-op 1 day | 0.66 logMAR | Standard Deviation 0.27 |
| Group I | Best-corrected Visual Acuity | Post-op 1 month | 0.89 logMAR | Standard Deviation 0.2 |
| Group I | Best-corrected Visual Acuity | Post-op 3 months | 0.98 logMAR | Standard Deviation 0.11 |
| Group II | Best-corrected Visual Acuity | Post-op 3 months | 1.01 logMAR | Standard Deviation 0.09 |
| Group II | Best-corrected Visual Acuity | Pre-op 1 day | 0.13 logMAR | Standard Deviation 0.11 |
| Group II | Best-corrected Visual Acuity | Post-op 1 month | 0.91 logMAR | Standard Deviation 0.13 |
| Group II | Best-corrected Visual Acuity | Post-op 1 day | 0.71 logMAR | Standard Deviation 0.2 |
| Group III | Best-corrected Visual Acuity | Post-op 3 months | 0.98 logMAR | Standard Deviation 0.1 |
| Group III | Best-corrected Visual Acuity | Post-op 1 day | 0.73 logMAR | Standard Deviation 0.23 |
| Group III | Best-corrected Visual Acuity | Post-op 1 month | 0.88 logMAR | Standard Deviation 0.14 |
| Group III | Best-corrected Visual Acuity | Pre-op 1 day | 0.15 logMAR | Standard Deviation 0.11 |