Alf Nyström

Optical properties of diffractive, bifocal, intraocular lenses

The resolution of diffractive, bifocal, intraocular lenses was studied with regard to pupil displacement and diameter size through computer simulations, bench measurements, and patient vision-acuity measurements. Good agreement was obtained between these three methods of investigation. In particular, we find that pupil displacements of the order of 1 mm reduce the resolution considerably for these lenses.

Combined Phacoemulsification, Primary Intraocular Lens Implantation, and Pars Plana Vitrectomy in Children with Uveitis*

Abstract Purpose: To evaluate the outcome of combined cataract surgery with primary intraocular lens (IOL) implantation and pars plana vitrectomy (PPV) in children with uveitis. Methods: Data regarding visual acuity (VA), inflammatory status, medical therapy, and complications was collected from the medical charts of 17 children (21 eyes) with chronic uveitis who underwent combined cataract surgery and PPV at the Eye Clinic, Sahlgrenska/Mölndal, between 2002 and 2011. Results: Seventy-six percent of the children had juvenile idiopathic arthritis. Median preoperative VA was 1.70 logMAR and median VA after 12 months was 0.17 logMAR. Postoperatively, glaucoma developed in 7 eyes, cystoid macular edema in 3 eyes, and visual axis opacification requiring treatment in 5 eyes. Conclusions: Although combined phacoemulsification, primary IOL implantation, and PPV in children with uveitis resulted in favorable visual outcome and stable inflammation in a majority of children, the technique should so far be reserved for uveitic cases with vitreous pathology.

Stability of visual outcome from 7 years in children treated surgically for bilateral dense congenital cataracts before 37 weeks of age

Acta Ophthalmol. 2011: 89: 30–36

Congenital cataract screening in maternity wards is effective: evaluation of the Paediatric Cataract Register of Sweden

To study which eye‐screening protocol prevails in Swedish maternity/neonatal wards, evaluate efficacy in a prospective study and compare results with earlier Swedish retrospective results.

Longitudinal change in aphakic refraction after early surgery for congenital cataract.

PURPOSE To characterize the longitudinal changes of refraction in aphakic eyes after early surgery for congenital cataract and to evaluate longitudinally measured aphakic refraction (individual vs group mean) as a noninvasive indicator of postoperative disturbances in ocular development. METHODS Records of children who had cataract surgery during their first year of life between 1980 and 1995 were obtained from a prospective, population-based study of congenital cataract. Only children with regular follow-up were included. Postoperative aphakic refraction was calculated at the corneal plane. Data were obtained up to 36 months of age. RESULTS The study included 28 children (49 eyes) who underwent surgery at a median age of 2.8 months (range, 0-9 months). The decrease of aphakic refraction at the corneal plane followed a logarithmic trend (R(2) = 0.95). A total of 36 eyes followed this pattern, with no growth in 8 eyes and an increased growth rate in 1 eye with uncontrolled glaucoma and 4 eyes of 2 children with Down syndrome. CONCLUSIONS Most aphakic eyes follow a predictable, logarithmic change in refraction in the first 3 years of life, Longitudinal monitoring of refraction may prove to be a useful, noninvasive screening method for early detection of disturbances in aphakic eye growth.

Outcome of surgical treatment of primary and secondary glaucoma in young children

To describe a paediatric cohort surgically treated for primary or secondary glaucoma (PG/SG), with regard to incidences, visual outcome and control of intraocular pressure (IOP).

The Pediatric Cataract Register (PECARE): analysis of age at detection of congenital cataract

To analyse and discuss screening for the detection of congenital cataract in two Nordic countries, Denmark and Sweden.

Letter imaging by diffractive, bifocal intraocular lenses: a computer study

Letter imaging of ideal-model diffractive, bifocal intraocular lenses is computer simulated. How the image is influenced by letter size, pupil diameter, and pupil displacement is studied. We find that the image quality is good as long as the letter sizes are not of the same order of magnitude as the unfocused background. If the sizes are comparable, considerable image degradation occurs.

The Paediatric Cataract Register (PECARE): an overview of operated childhood cataract in Sweden and Denmark

To report basic epidemiological data concerning surgically treated childhood cataract in Sweden and Denmark.

Optical properties of diffractive, bifocal intraocular lenses

The resolution of diffractive, bifocal intraocular lenses was studied with regard to pupil displacement and diameter size through computer simulations, bench measurements and patient vision acuity measurements. Good agreement was obtained between these three methods of investigation. In particular we find that pupil displacements of the order of 1 mm reduce the resolution considerably for these lenses.