Mini-monovision with monofocal lenses
Research type
Research Study
Full title
Prospective, non-randomised, single arm study on visual and optical outcomes after mini-monovision with hydrophobic monofocal intraocular lens
IRAS ID
335566
Contact name
Mayank Nanavaty
Contact email
Sponsor organisation
University Hospitals Sussex NHS Foundation Trust
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
The most frequently implanted intraocular lenses (IOLs) are still monofocal lenses, because of their relatively low cost, their excellent outcome for distance, and the low incidence of photic phenomena, in eyes with comorbidities such as corneal or macular diseases. The increasing importance of the intermediate distance tasks in modern everyday life has led to a growing interest toward IOLs that may also reduce spectacle independence for intermediate distances without significant unwanted side effects, thus improving some quality-of-life aspects.1-3 These tasks within the intermediate range often depend on lighting (and con¬sequently pupil diameter) and require additional refrac¬tive correction. Ni et al.4 developed a real-life vision test to analyse the correlation of distance, near, and intermedi¬ate visual acuity with the score in fulfilling several tasks adopted from real-life situations, such as picking fruit and facial recognition at various distances. They found a significant correlation between intermediate vision and the ability to perform these tasks. The more recent IOLs, based on diffractive technology, such as trifocal or extended-range-of-vision (ERV) IOLs, are capable of improving intermediate vision but they are not available on the NHS and they still require an accurate patient selection and neural adaptation to enhance benefits and minimize unwanted visual effects.1-3
Monovision using traditional monofocal IOLs is a surgical option that corrects distance vision in one eye; the other eye focuses intentionally for near to mid-range vision with the same monofocal lens. This leads to the process of neuroadaptation where the brain can use the distance image from the dominant eye and the near image from the non-dominant eye to achieve a wider range of functional vision.5 In this surgery the amount of intended near to mid-range power (myopia) can vary, with full monovision defined as the reading eye exhibiting a residual refractive error of −2.50 diopters or more. Modified monovision or “mini-monovision” requires a smaller interocular diopteric power difference between eyes than traditional full monovision, typical calculations of the eye to focus for intermediate distances are anywhere between −0.75 and −1.75 diopters of myopia. Patients with significant astigmatism can also undergo mini-monovision surgery with astigmatism correction.
The trifocal and ERV IOLs are expensive and therefore not available in the public sector. There is a need for a procedure which give equivalent results without increasing the cost. Whereas, mini-monovision approach with the existing monofocal IOLs (which are available in the public sector) may be an alternative option to give equivalent outcomes comparable to trifocal and ERV IOLs. We designed this study to assess the binocular distance and intermediate visual performance after bilateral implantation of hydrophobic monofocal intraocular lenses (IOL) with mini-monovision in patients with bilateral cataracts.REC name
North West - Preston Research Ethics Committee
REC reference
24/NW/0192
Date of REC Opinion
10 Jul 2024
REC opinion
Further Information Favourable Opinion