Rotational Stability of V4C Toric Implantable Contact Lenses After On Axis Implantation Measured With OPD Scan 3

Study Overview
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Brief Summary
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The recently introduced toric V4c toric ICL (STAAR Surgical Company, Monrovia, CA, USA) has been designed with a 360-µm central hole to allow aqueous humor to flow without the need for an iridotomy. As far as the investigators certain, there have been not well-established prospective studies on the role of the V4c toric ICL for myopic astigmatism correction. Therefore, the present study aimed to investigate the clinical outcomes and rotational stability and to analyze factors that influence the rotational stability in V4c toric ICL implanted eyes prospectively.

Official Title
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Rotational Stability of V4C Toric Implantable Contact Lenses After On Axis Implantation Measured With OPD Scan 3

Conditions
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Myopic Astigmatism

Intervention / Treatment
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* Procedure: V4c toric ICL implantation surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 19-45 years Presence of myopia with a manifest refraction spherical equivalent between -5.00 and -20.00 diopters (D) Astigmatism between -0.75 and -5.00 D Exclusion Criteria: Previous ocular or intraocular surgery (other than ICL implant) Anterior chamber depth from the endothelium < 2.8 mm Corneal endothelial cell density < 2000 cells/mm2 Evidence of acute or chronic corneal infection, corneal inflammation Glaucoma, amblyopia, retinal detachment, diabetic retinopathy, macular degeneration, or neuro-ophthalmic disease

Ages Eligible for Study
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Minimum Age: 19 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: V4c toric ICL implantation Group<br>V4c toric ICL implantation Group | Procedure: V4c toric ICL implantation surgery<br>* The size and power of the V4c toric ICL were determined following the manufacturer's guidelines using a modified vertex formula. Emmetropia was the target refraction following surgery in all cases. Before surgery, three centration points were marked using the slit lamp while the patient, in sitting position, fixated on the center of the slit-lamp beam, which was narrowed as much as possible.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual outcome | Evaluation of logarithm of the minimum angle of resolution (logMAR) uncorrected distance visual acuity (UDVA) and CDVA, manifest refraction, autorefractor-keratometer (ARK-530A; Nidek Co., Ltd.). The change of astigmatism was analyzed by the Alpins method. | 6 months after the surgery | 
| Refractive outcome | Evaluation of logarithm of the minimum angle of resolution (logMAR) uncorrected distance visual acuity (UDVA) and CDVA, manifest refraction, autorefractor-keratometer (ARK-530A; Nidek Co., Ltd.). The change of astigmatism was analyzed by the Alpins method. | 6 months after the surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rotational stability | Rotational stability of the toric ICL was measured using the OPD-Scan III (NIDEK Co. Ltd., Gamagori, Japan). The rotation was defined as the difference between the intended axis and the achieved axis at each follow-up. Assuming that the adjusted axis was identical to the intended angle, postoperative rotation was automatically measured by determining the angle between the adjusted axis and alignment axis. Each measurement was performed three times by one physician, and the average of the three measurements was used in the analysis. | immediately after the surgery | 
| Rotational stability | Rotational stability of the toric ICL was measured using the OPD-Scan III (NIDEK Co. Ltd., Gamagori, Japan). The rotation was defined as the difference between the intended axis and the achieved axis at each follow-up. Assuming that the adjusted axis was identical to the intended angle, postoperative rotation was automatically measured by determining the angle between the adjusted axis and alignment axis. Each measurement was performed three times by one physician, and the average of the three measurements was used in the analysis. | 3 months after the surgery | 
| Rotational stability | Rotational stability of the toric ICL was measured using the OPD-Scan III (NIDEK Co. Ltd., Gamagori, Japan). The rotation was defined as the difference between the intended axis and the achieved axis at each follow-up. Assuming that the adjusted axis was identical to the intended angle, postoperative rotation was automatically measured by determining the angle between the adjusted axis and alignment axis. Each measurement was performed three times by one physician, and the average of the three measurements was used in the analysis. | 6 months after the surgery |