Small incision corneal lenticule extraction for myopia and myopic anisometropia
| ISRCTN | ISRCTN26161084 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN26161084 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | Nil known |
| Sponsor | State Key Laboratory of Ophthalmology |
| Funder | The Science and Technology Program of Guangzhou, China (2023A04J1891) |
- Submission date
- 14/12/2023
- Registration date
- 10/01/2024
- Last edited
- 15/12/2023
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Eye Diseases
Plain English summary of protocol
Background and study aims
Myopic anisometropia is a condition where you have one normal eye and one nearsighted (or myopic) eye. The aim of this study is to assess the effect of small incision lenticule extraction (SMILE), a type of laser eye surgery, on patients with myopic anisometropia.
Who can participate?
Patients aged 18 to 30 years with myopic anisometropia treated with small incision lenticule extraction (SMILE)
What does the study involve?
All participants receive the same treatment with SMILE and undergo eye tests before surgery and at 1 week and 1, 3 and 6 months after surgery,
What are the possible benefits and risks of participating?
Participants receive free eye tests. There are no expected side effects of the treatment.
Where is the study run from?
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University (China)
When is the study starting and how long is it expected to run for?
January 2015 to July 2016
Who is funding the study?
The Science and Technology Program of Guangzhou (China)
Who is the main contact?
Dr Shengbei Weng, 1023816828@qq.com
Contact information
Public, Scientific, Principal investigator
Guangzhou Women and Children's Medical Center
Guangzhou Medical University
Guangdong Provincial Clinical Research Center for Child Health
Guangzhou
510623
China
 ORCID ID |
0000-0003-0938-0014 |
|---|---|
| Phone | +86 (0)13711552618 |
| 1023816828@qq.com |
Study information
| Primary study design | Observational |
|---|---|
| Study design | Single-centre observational longitudinal case-control study |
| Secondary study design | Longitudinal study |
| Study type | Participant information sheet |
| Scientific title | Evaluation of visual outcomes and binocular vision functions following small incision corneal lenticule extraction for myopia and myopic anisometropia |
| Study objectives | Small incision corneal lenticule extraction (SMILE) is a predictable, effective, and safe method for correcting myopic anisometropia in adults without amblyopia. |
| Ethics approval(s) |
Approved 21/02/2015, Ethics Committee of Zhongshan Ophthalmic Center at the Sun Yat-sen University (State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, 510060, China; +86 (0)13711552618; zocdpo@gzzoc.com), ref: 2013MEKY036 |
| Health condition(s) or problem(s) studied | Myopic anisometropia |
| Intervention | The ocular parameters used for characterizing binocular functions include: divergence and convergence amplitudes (near and distance), stereoacuity (near and distance), and near and distance horizontal phorias. The Risley rotary prisms are used to evaluate the horizontal vergence ranges. A gradually increasing horizontal Risley prism is placed in both eyes while the patient fixated on a line of Snellen optotype E. Equal amounts of rotatory prism are slowly added in front of each eye (base-in and base-out prism for divergence and convergence, respectively) at a constant velocity (approximately 2 Δ/s) until the subject first reported horizontal diplopia (break value). The distance stereoacuity is tested using the stereotest booklet (Distance Randot Stereotest, Stereo Opticals Co., Inc., range: 400-60 arcsec) at 3 meters (m) in a standard illuminated room with polarizing glasses. Near stereoacuity is measured at 40 centimeters (cm) using the Randot circles test (Stereo Randot Test 2 for Adults, Stereo Optical, ranged: 400-12.5arcsec); the graded circles are used to quantify stereopsis. Heterophoria measurements are obtained using the von Graefe technique: a 6 Δ base-up dissociating prism is placed in front of the right eye, and horizontal oculomotor deviation neutralized with a Risley rotary prism in front of the left eye. |
| Intervention type | Other |
| Primary outcome measure(s) | 1. Divergence and convergence amplitudes (near and distance) are measured using Risley rotary prisms preoperatively and at 1 week, 1, 3 and 6 months after surgery 2. Distance stereoacuity is measured using the stereotest booklet (Distance Randot Stereotest, Stereo Opticals Co., Inc., range: 400-60 arcsec) preoperatively and at 1 week, 1, 3 and 6 months after surgery 3. Near stereoacuity is measured using the Randot circles test (Stereo Randot Test 2 for Adults, Stereo Optical, ranged: 400-12.5arcsec) preoperatively and at 1 week, 1, 3 and 6 months after surgery 4. Heterophoria measurements are measured using Risley rotary prism preoperatively and at 1 week, 1, 3 and 6 months after surgery |
| Key secondary outcome measure(s) | Monocular uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) are measured using Snellen charts preoperatively and at 1 week,1,3 and 6 months after surgery |
| Completion date | 27/07/2016 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 30 Years |
| Sex | All |
| Target sample size at registration | 49 |
| Total final enrolment | 49 |
| Key inclusion criteria | 1. Aged 18 to 30 years, stable myopia for ≥1 year 2. Corrected distance visual acuity (CDVA) of 20/20 or better 3. SE of -1.00 to -10.00 diopters (D) with or without myopic astigmatism (< -1.5D) 4. Qualified for laser refractive surgery for myopia (normal ocular anterior segment examination except for refractive error) |
| Key exclusion criteria | 1. Patients with any ocular surface diseases 2. History of corneal or intraocular surgery, ocular trauma, keratoconus, cataract, vascular, or autoimmune diseases |
| Date of first enrolment | 01/09/2015 |
| Date of final enrolment | 27/01/2016 |
Locations
Countries of recruitment
- China
Study participating centre
Guangzhou.
510060
China
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | The datasets generated during and/or analysed during the current study will be available upon request from Shengbei Weng (1023816828@qq.com). The data will be shared in Excel form from 15/12/2024. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
15/12/2023: Study's existence confirmed by the Ethics Committee of Zhongshan Ophthalmic Center at the Sun Yat-sen University.
