Assessing The Visual Performance Of Hanita Lenses "Intensity SL" Intraocular Lens

Different multifocal intraocular lens (MIOL) designs have been used for more than 25 years1. Unlike conventional mono focal intraocular lenses (IOLs), which bend light to a single focus point on the retina, MIOLs are designed to help patients to see at varying distances using different points of focus2. MIOLs used in clinical practice were either refractive initially, or later diffractive in their optical design. Refractive MIOLs incorporate a lens optic with different optical powers in different parts of the lens, while diffractive MIOLs use diffractive steps on the lens to distribute light rays into two or more principal foci. Irrespective of the design type, however, all MIOLs involve some form of optical compromise and a process of neuroadaptation for the patient3.

Intensity SL intraocular lenses (IOLs) represent the latest in premium lens technology. Intensity SL lenses provide clear vision at all distances - from near to far - thus offering the best chance of true spectacle independence.

Despite the promising results obtained with the latest generation of MIOLs, many surgeons remain reluctant to implant these lenses. Visual symptoms such as glare and haloes, reduced contrast sensitivity and night vision problems are all known complications of multifocal implants and have served to hamper wider acceptance of these IOLs4.

Hanita Lenses new Intensity SL IOL has been designed to have very high efficiency of light leading to a high MTF, wide focal ranges of far, intermediate and near vision and minimal loss of light energy. The main purpose of this study is to evaluate visual acuity and contrast sensitivity patients receiving the new Intensity SL IOL.

Inclusion criteria

• • Age over 45 years and under 75 years.

• Patients with bilateral age related cataracts, require bilateral cataract phacoemulsification combined Intraocular Lens implantation;
• Calculated IOL power is within range 15-30 Diopter (approximate range of axial lengths: 21-25.5mm)
• Normal corneas with corneal astigmatism below following value:

• 1 D if with-the-rule (steep axis is vertical, between 60-120⁰)
• 0.4 D if against-the-rule (steep axis is horizontal, 0-30⁰ or 150-180⁰)
• 0.7 D if oblique (not one of the cases above)
• Post-operative best corrected visual acuity expected to be 0.3 logMAR or better.
• Patient motivated for Intensity SL IOL after screening by surgeon.
• Fundus visualization is possible.
• Absence of retinal or optic nerve diseases
• Signed informed consent

Exclusion criteria

• Any of the following condition will render a subject ineligible for inclusion in the analysis:

• Previous ocular/corneal surgery that may affect refraction accuracy or visual acuity.
• Capsule or zonular abnormalities that may affect postoperative centration or tilt of the lens (e.g. pseudoexfoliation syndrome, chronic Uveitis, Marfan's syndrome)
• History or evidence of any ocular disease that may affect visual acuity (i.e. uncontrolled glaucoma, ocular injury, corneal pathologies, retinal pathologies in general and macular pathologies in particular, diabetic retinopathy, uveitis, aniridia or iris atrophy, vitreous pathologies (patients with vitreous separation or floaters can be included).
• Rubella cataract.
• Amblyopia
• Significantly dry eye
• Any other ocular condition that may predispose a subject to future complications or contraindicate implantation of the Intensity SL lens.
• Pupil abnormalities (non-reactive, tonic pupils, abnormally shaped pupils, or pupils that do not dilate at least 3.5 mm under mesopic/scotopic conditions)
• Patients with pupil diameter greater than 4mm in photopic conditions.
• Pregnant, lactating, or planning to become pregnant during the course of the trial.
• Allergy or intolerance to required study medications (including antibiotic).
• Subjects participating in a concurrent clinical trial or if they have participated in an ophthalmology clinical trial within the last 30 days.
• Traumatic cataract.