Gunilla Magnusson

Distribution and growth dynamics of ephemeral macroalgae in shallow bays on the Swedish west coast

Abstract Distribution and growth dynamics of ephemeral macroalgae were investigated in some shallow (0–1 m) bays on the Swedish west coast during the period 1992 to 1994. Variation in cover and biomass was assessed in nine bays, and in one of them the seasonal dynamics of these algae was followed intensively over three years. Frequent measurements were taken of algal biomass, degree of cover, in situ growth, variable fluorescence and C/N-ratios. Irradiance and water nutrient concentrations were measured concurrently with the growth measurements. Ephemeral macroalgae were dominated by Cladophora and Enteromorpha species and occurred in all sampled bays, except one, covering 10 to 100% of the bottom sediment. Generally, a rapid biomass increase was recorded from mid-May, which peaked after six weeks at 400–600 g dwt·m−2. Later in the season, strong variations in biomass, cover and species composition were observed, suggesting that these opportunistic algae form a highly dynamic community. Initial growth rates estimated from biomass samples were similar to those recorded from in situ cage experiments, and also agreed with growth rates calculated from a model. For all species studied growth rate was within the range 10 to 30 g dwt·m−2·d−1, irrespective of method used. Low algal C/N-ratios (mean = 12.7) in 1993 (cold and rainy summer) indicated that growth was not limited by nutrients, but rather by light. In 1994 (warm and sunny summer), mean C/N-ratios were 20, reflecting the opposite situation. The appearance of these opportunistic algae in shallow bays which historically had been without macroalgal communities has changed the characteristics of these areas by altering habitat complexity. This could have important consequences for trophic interactions involving many species, thereby altering community structure and function.

Evaluation of screening procedures for congenital cataracts

AIM To evaluate the efficacy of two different Swedish screening procedures for early detection of congenital cataracts in comparison with no screening. METHODS Children born between January 1992 and December 1998 in Swedish regions with an established eye-screening routine procedure, diagnosed with congenital cataract, and operated on before 1 y of age, were included in a retrospective study. Age at referral and age at time of the operation were compared between regions using different screening procedures: screening in the maternity wards (Region 1), at the well-baby clinics (Region 2) and one region without any screening (Region 3). RESULTS Seventy-two children were included in the study. Concerning early diagnosis and surgery, Region 1 differed significantly from Regions 2 and 3, which were more similar and were combined for further analysis. The difference in detected cases was greatest at 21 d of age (55% vs 18%; p < 0.001), but persisted even at 100 d of age (78% vs 64%; p < 0.02). Region 1 screening resulted in more and earlier cases detected than the other two regions (22 vs 15 per 100,000 births). In 72% of all cases, surgery was performed in response to referrals from either the maternity wards (36%), or the well-baby clinics (36%). However, half of the cases from the well-baby clinics were detected too late, i.e. at > 100 d. CONCLUSION Eye screening in the maternity ward is preferable to well-baby clinic screening and to no screening at all, since it leads to early detection. Screening should also be performed routinely at well-baby clinics within the period when successful treatment is possible.

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

Screening for congenital cataracts: A cost-consequence analysis of eye examination at maternity wards in comparison to well-baby clinics

Aim: To estimate, on a national basis in Sweden, the costs versus consequences of combined maternity ward and well-baby clinic eye screening compared to well-baby clinic screening alone. Methods: Two scenarios were created and compared regarding healthcare costs: visual acuity development and quality-adjusted life-years (QALYs). One scenario represented early management ( combined maternity ward and well-baby clinic screening); the other represented less early management (well-baby clinic screening only). Each scenario was based on 100 000 births, and the healthcare costs were calculated from detection until age 18 y. All estimates of prevalence, visual outcome, postoperative complications and screening procedures were based on previous, recently published studies. Estimated costs were obtained from St. Eriks Eye Hospital in Stockholm and the University Hospital of Lund, at 2001 prices. Results: Total cost of the maternity ward/well-baby clinic screening scenario was 7.9 million SEK, and that of the maternity ward screening scenario was 6.9 million SEK. The incremental cost-effectiveness ratio was estimated at 234 000 SEK/QALY provided three more children per year were detected in Sweden by mandatory maternity ward/well-baby clinic screening. Conclusion: The incremental expense of introducing combined maternity ward/well-baby clinic eye screening on a nationwide basis is cost effective and within acceptable levels of cost/QALY when compared with other widely accepted therapies across diverse medical specialties.

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.

Resolution visual fields in children surgically treated for bilateral congenital cataract

PURPOSE To evaluate visual acuity (best corrected visual acuity) and peripheral sensitivity, measured by high-pass resolution (HRP) visual fields, in children surgically treated for congenital cataract. METHODS Acuity and peripheral sensitivity were recorded from 16 children, aged 10 to 15 years, either surgically treated for bilateral dense cataract before the age of 4.6 months (n = 10) or surgically treated for bilateral partial cataract at ages 4 to 139 months (n = 6). Data from 22 healthy children, mean age 11 years, served as control. RESULTS The children with cataract had significantly (P < 0.0001) lower decimal acuity in their better eye (median, 0.55; range, 0.1-1.3) than did the control subjects (median, 1.2; range, 1.0-1.6). Five children were visually impaired according to the World Health Organizations definition (i.e., acuity in the better eye <0.3). The children with previous dense bilateral cataract showed significantly lower peripheral sensitivity than did the control subjects (P = 0.004). Significant correlations were observed between acuity and visual field parameters. CONCLUSIONS Dense cataract, even when surgically treated before the age of 4.6 months, causes persistent impairment of spatial vision, both in the fovea and the visual field. The effect on the visual field is less pronounced than that on visual acuity. This finding has to be taken into account when evaluating visual field results in, for example, the diagnosis of glaucoma, a frequent complication after cataract surgery in early infancy.

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.

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.

Screening for congenital cataracts: A cost-consequence analysis of eye examination at maternity wards in comparison to well-baby clinics: Cost-consequence of screening for congenital cataracts

Aim: To estimate, on a national basis in Sweden, the costs versus consequences of combined maternity ward and well‐baby clinic eye screening compared to well‐baby clinic screening alone. Methods: Two scenarios were created and compared regarding healthcare costs: visual acuity development and quality‐adjusted life‐years (QALYs). One scenario represented early management (combined maternity ward and well‐baby clinic screening); the other represented less early management (well‐baby clinic screening only). Each scenario was based on 100 000 births, and the healthcare costs were calculated from detection until age 18 y. All estimates of prevalence, visual outcome, postoperative complications and screening procedures were based on previous, recently published studies. Estimated costs were obtained from St. Eriks Eye Hospital in Stockholm and the University Hospital of Lund, at 2001 prices. Results: Total cost of the maternity ward/well‐baby clinic screening scenario was 7.9 million SEK, and that of the maternity ward screening scenario was 6.9 million SEK. The incremental cost‐effectiveness ratio was estimated at 234 000 SEK/QALY provided three more children per year were detected in Sweden by mandatory maternity ward/well‐baby clinic screening.