Rotational Stability After Nanoflex Collamer Toric Intraocular Lens Implantation in Astigmatic Patients

Study Overview
=================
Brief Summary
-----------------
This study aims to assess the rotational stability of the new collameric Nanoflex toric intraocular lens (T-IOL) by STAAR inserted in astigmatic patients after cataract surgery. The purpose of this study is also to determine whether the use of a toric intraocular lens (T-IOL) improves visual acuity.

Detailed Description
-----------------
A good rotational stability of toric intraocular lenses (T-IOL) allows an accurate refractive correction. However, many aspects -both pre-operative and post-operative- can interfere causing T-IOL rotation and misalignment. Complete preoperative ocular evaluation is performed including slit-lamp examination, uncorrected distance visual acuity (UDVA), best-corrected visual acuity (BCVA), Javal keratometry, corneal Scheimplug tomography (Pentacam), optical biometry (IOL Master), Goldman applanation tonometry and fundus evaluation through dilated pupils. The spherical IOL power is calculated considering the axial length obtained with optical biometry, the magnitude of astigmatism derived from Javal keratometry and the steepest axis obtained with corneal tomography. The power of the toric IOL is determined with the online Staar Toric IOL calculator. The reference landmarks are also marked preoperatively with a sterile methylene blue fine point pen. The marking is rechecked in the operating theatre with the electronic toric marker ASICO. Postoperative evaluation for IOL alignment and rotational stability is performed with slit-lamp photography on dilated pupils. Images are captured with Haag Streit slit lamp BQ 900 and are evaluated with the image-analysis software Protractor (Staar).

Official Title
-----------------
Rotational Stability After Nanoflex Collamer Toric Intraocular Lens Implantation in Astigmatic Patients Undergoing Cataract Surgery

Conditions
-----------------
Astigmatism

Intervention / Treatment
-----------------
* Procedure: Phacoemulsification with toric Nanoflex IOL implantation
* Device: NanoFlex toric Intraocular Lens


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients of 60 years of age ore more Cataract Corneal astigmatism of 1 diopter (D) or more Exclusion Criteria: Primary or secondary pathological conditions of the cornea Zonular fibres pathologies (phacodonesis, pseudoexfoliation syndrome) Irregular astigmatism (corneal scar, keratoconus, pterygium) Traumatic cataract Previous ocular surgery Complications during cataract surgery

Ages Eligible for Study
-----------------
Minimum Age: 60 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Toric Nanoflex IOL<br>Phacoemulsification with toric Nanoflex IOL implantation | Procedure: Phacoemulsification with toric Nanoflex IOL implantation<br>* A self-sealing incision is made with a 2.2mm knife at 110°. Phacoemulsification is performed. The foldable nanoFlex toric IOL is injected in the capsular bag using the nanoPoint single-use injector system (STAAR) or 1620 sofTip Injector (ASICO). The IOL is rotated to align the cylinder axis with the steep corneal meridian using Z align function by Callisto Eye. Every movement of the IOL axis marks are noted.<br>Device: NanoFlex toric Intraocular Lens<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in rotational stability of the toric intraocular lens (T-IOL). | The misalignment of the lens is defined as the difference (Δ) between the intended axis and the actual axis of the new collameric Nanoflex T-IOL by STAAR. | Change of rotational stability at 1 day, 1 week, 1 month, 3 months, 6 months, 12 months and 18 months after surgery. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correction of the astigmatism. | Effective correction evaluated through corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA). | Change in visual acuity at 1 day, 1 week, 1 month, 3 months, 6 months, 12 months and 18 months after surgery |