Inducing cylindrical and spherical defocus after implantation with new generation intraocular lenses improves intermediate and near visual acuity

Abstract

An induced cylinder and spherical power after implantation with an extended depth of focus (EDOF) and enhanced monofocal intraocular lens (IOL) could improve distance, intermediate (60 cm) and near (40 cm) visual acuity (VA). In this prospective study, forty eyes with Eyhance EDOF IOL (Johnson and Johnson, USA) and 40 eyes with Vivity EDOF IOL (Alcon Laboratories Inc. USA) were included. Induced cylinder (applied to non-dominant eye) in steps of + 0.25D were used and then VA was measured monocularly (only non-dominant eye). Similarly, induced sphere (applied to non-dominant eye) in steps of + 0.25D were used and then VA was measured monocularly (only non-dominant eye). The above methods were repeated for the dominant eye as well. Then, binocular defocus curve for each patient was obtained by inducing optimal sphere and cylinder (one at a time in front of the non-dominant eye only). In both IOL groups, induced cylinder and sphere independently led to significant improvement in near and distance vision (p < 0.05). Induced sphere binocularly caused a greater decrease (~ 0.1 LogMAR) in distance VA compared to induced cylinder but this was not clinically significant. Most patients accepted an induced cylinder of +1.0 to +1.5D in both IOL groups. Induced cylinder and sphere caused a favourable improvement in near and intermediate VA after surgery in both IOL groups without a significant drop in distance VA.

Keywords: Cataract; Cylinder; Defocus; Eyhance; Monovision; Vivity.

Fig. 1

(a) Defocus curve derived from monocular testing of non-dominant eye (with induced cylinder) implanted with Eyhance intraocular lens; (b) Defocus curve derived from monocular testing of non-dominant (with induced cylinder) eye implanted with Vivity intraocular lens. Patients were made emmetropic for distance before the defocus curve was measured.

Fig. 2

(a) Defocus curve derived from binocular testing with induced cylinder in the non-dominant eye implanted with Eyhance intraocular lens; (b) Defocus curve derived from binocular testing with induced cylinder in the non-dominant eye implanted with Vivity intraocular lens. Patients were made emmetropic for distance before the defocus curve was measured.

Fig. 3

(a) Defocus curve derived from monocular testing of non-dominant eye (with induced sphere) implanted with Eyhance intraocular lens. Data from Fig. 1a is also included for comparison; (b) Defocus curve derived from monocular testing of non-dominant (with induced sphere) eye implanted with Vivity intraocular lens. Data from Fig. 1b is also included for comparison. Patients were made emmetropic for distance before the defocus curve was measured.

Fig. 4

(a) Defocus curve derived from binocular testing with induced sphere in the non-dominant eye implanted with Eyhance intraocular lens. Data from Fig. 2a is also included for comparison; (b) Defocus curve derived from binocular testing with induced sphere in the non-dominant eye implanted with Vivity intraocular lens. Data from Fig. 2b is also included for comparison. Patients were made emmetropic for distance before the defocus curve was measured.