Halo size under distance and near conditions in refractive multifocal intraocular lenses

Abstract

Conclusions-Under high contrast conditions halos can be stimulated in all patients with multifocal intraocular lenses. The halo size using the distance or the near focus is identical. (Br J Ophthalmol 2001;85:816-821)

Disk halo size measured in individuals with monofocal versus diffractive multifocal intraocular lenses

“…10 Therefore, the difference in halo radius between our 2 IOL groups (comparable to a difference of 20%) seems to be unaffected by wavefront aberrations but may be the result of the diffractive component of the multifocal IOL. Other multifocal IOL designs, refractive 4 and zonal-progressive, 16 have also been found to induce a significantly larger halo size than monofocal IOLs. Recently, increased light-distortion index or best-fit circle radius of the distortion area have been found after refractive lens exchange with diffractive multifocal IOLs in comparison with monofocal IOL.…”

“…11 Few studies have centered on obtaining objective halo size measurements in subjects implanted with an intraocular lens. 4, 16 Dick et al 16 detected a significantly greater mean halo size in subjects older than 70 years with zonal-progressive multifocal IOLs compared to monofocals. 16 Refractive multifocal IOLs were also found to give rise to a significantly greater halo size than monofocals.…”

“…4 The unwanted effect of the light in the out-of-focus image may be visually disturbing, depending on 2 factors: the distance along the optical axis between these 2 images (the greater the distance between the 2 separate focal points along the optical axis, the greater will be the diffusion or blur circle surrounding the primary focus), and their relative energy distribution (the energy of the distant and near images is a function of pupil size). 5 As a consequence, contrast sensitivity and undesirable optical effects such as glare and/or halos may be worse in eyes implanted with a multifocal rather than a monofocal IOL.…”

“…16 Refractive multifocal IOLs were also found to give rise to a significantly greater halo size than monofocals. 4 Halometry has been used to measure the angular size of photopic scotomas arising from a glare source in subjects with diffractive trifocal IOLs. 17 To the best of our knowledge, however, no study has compared examined halo size measurements related to the use of diffractive multifocal and monofocal IOLs.…”

Implantation of refractive multifocal intraocular lens with a surface-embedded near section for cataract eyes complicated with a coexisting ocular pathology

“…1 In refractive MIOLs, halo or glare symptoms are more prominent than in diffractive MIOLs because of light scattering at the transitional zone between the distant and near focus of the MIOL. 2 In addition, the near visual acuity (VA) when using refractive MIOLs tends to depend on pupil size because of the near focus zone of the MIOL being concentrically allocated. 3 On the other hand, one underlying problem associated with diffractive MIOLs is the reduced contrast post implantation due to the optical feature of the lens.…”