A Prospective Study On Pseudophakic Mini-Mono Vision Using Monofocal Intraocular Lens

To assess binocular spectacle independence for distance and intermediate vision and functionality of intermediate vision performance by reading speed after bilateral cataract surgery with mini-monovision (0.75 D difference)

Sussex Eye Hospital, University Hospitals Sussex NHS Foundation Trust, Brighton.

A prospective, non-randomised, single-arm cohort study on visual and optical outcomes after mini-monovision surgery, using Clareon monofocal intraocular lens (Alcon). All patients underwent immediate sequential bilateral cataract surgery. The dominant eye was aimed for distance emmetropia, and the other eye for -0.75D. Patients were followed up at 1 and 3 months. The primary outcome was binocular uncorrected intermediate visual acuity (UIVA). Secondary outcomes included monocular & binocular uncorrected (UDVA), best corrected distance visual acuity (BCDVA) at 4 meters and monocular UIVA. The tertiary outcomes were binocular defocus curve, binocular reading speed with Salzburg reading desk and Catquest 9SF questionnaire.

Twenty-seven patients were included. The primary outcome, binocular UIVA, at three-months was 0.08 ±0.15 LogMAR. Secondary outcomes included binocular and monocular UCDVA, which were -0.02 ±0.11 and 0.03 ±0.16  LogMAR at 1 month and -0.05 ±0.11 and 0.03 ±0.12 LogMAR at 3 months, respectively. In the tertiary outcomes, the binocular defocus curve showed visual acuity of 0.1 LogMAR or better between -1.5 D and +0.5 D, Binocular uncorrected reading speed with Salzburg reading desk at 66 cm was 153 ±155 words per minute with 0.07 ±0.09 LogMAR. Analysis of the Catquest 9SF questionnaire using Rasch weighted scores found a statistically significant higher score postoperatively at 1 and 3 months, compared to the pre-op questionnaire (p<0.01).

In conclusion, immediate sequential bilateral cataract surgery with mini-monovision technique using Clareon^® monofocal IOLs (-0.75 D offset) demonstrated favorable visual and functional outcomes. At three months, patients achieved excellent binocular intermediate and distance visual acuity. The defocus curve confirmed a broad range of functional vision together with good reading performance. Patient-reported outcomes reflected high satisfaction, as indicated by the Catquest 9SF scores. These findings highlight the effectiveness of this approach in providing excellent functional vision, ranging from distance to intermediate, and patient satisfaction.