Optic nerve hypoplasia: Risk factors and epidemiology.

OBJECTIVES: To study the epidemiology of optic nerve hypoplasia. DESIGN AND METHODS: Children with optic nerve hypoplasia and visual impairment were identified through the Swedish Register of Visually Impaired Children. Pre- and perinatal characteristics were obtained from the Medical Birth Registry and by scrutinizing pregnancy and delivery records. Clinical characteristics of children with optic nerve hypoplasia are described. The following risk factors were studied: maternal age, parity, maternal smoking, gestational duration, birth weight, delivery method, Apgar score, maternal disease during pregnancy, drugs used in early pregnancy. RESULTS: Young maternal age, first parity, maternal smoking, preterm birth and factors associated with preterm birth were risk factors for optic nerve hypoplasia. There was an indicated association with the use of fertility drugs and antidepressant drugs. CONCLUSIONS: Optic nerve hypoplasia is apparently associated not only with other anomolies, notably of the central nervous system, but also with signs of general disturbance in fetal development

Development and validation of a new clinical decision support tool to optimize screening for retinopathy of prematurity

Background/Aims Prematurely born infants undergo costly, stressful eye examinations to uncover the small fraction with retinopathy of prematurity (ROP) that needs treatment to prevent blindness. The aim was to develop a prediction tool (DIGIROP-Screen) with 100% sensitivity and high specificity to safely reduce screening of those infants not needing treatment. DIGIROP-Screen was compared with four other ROP models based on longitudinal weights. Methods Data, including infants born at 24–30 weeks of gestational age (GA), for DIGIROP-Screen development (DevGroup, N=6991) originate from the Swedish National Registry for ROP. Three international cohorts comprised the external validation groups (ValGroups, N=1241). Multivariable logistic regressions, over postnatal ages (PNAs) 6–14 weeks, were validated. Predictors were birth characteristics, status and age at first diagnosed ROP and essential interactions. Results ROP treatment was required in 287 (4.1%)/6991 infants in DevGroup and 49 (3.9%)/1241 in ValGroups. To allow 100% sensitivity in DevGroup, specificity at birth was 53.1% and cumulatively 60.5% at PNA 8 weeks. Applying the same cut-offs in ValGroups, specificities were similar (46.3% and 53.5%). One infant with severe malformations in ValGroups was incorrectly classified as not needing screening. For all other infants, at PNA 6–14 weeks, sensitivity was 100%. In other published models, sensitivity ranged from 88.5% to 100% and specificity ranged from 9.6% to 45.2%. Conclusions DIGIROP-Screen, a clinical decision support tool using readily available birth and ROP screening data for infants born GA 24–30 weeks, in the European and North American populations tested can safely identify infants not needing ROP screening. DIGIROP-Screen had equal or higher sensitivity and specificity compared with other models. DIGIROP-Screen should be tested in any new cohort for validation and if not validated it can be modified using the same statistical approaches applied to a specific clinical setting

Corneal Involvement in Congenital Aniridia.

PURPOSE:: The purpose of this research is 2-fold. First of all, the level of keratopathy development in patients with congenital aniridia is studied. In addition, a correlation between the effects of ocular surgery on the severity of keratopathy is made. METHODS:: A thorough search for the total number of patients with aniridia in Sweden and Norway was performed. One hundred eighty-one patients were identified and 124 (69%) of these were examined. Three artificial eyes, 16 eyes with corneal transplants, and 1 eye with a corneal limbal allograft were excluded from the study. All participating patients underwent clinical ophthalmologic examinations, including photographs, and their medical history was recorded. A slit lamp was used to examine the presence of keratopathy. RESULTS:: Visible keratopathy was found in 80% of the eyes. Keratopathy that caused impaired visual acuity was found in 26% of the eyes. The study displayed a significant correlation between the level of keratopathy and the patient's age. A significant correlation between the level of keratopathy and intraocular surgery exists. This is irrespective of the patient's age. The study also found that irrespective of the patient's age, a significant correlation between the level of keratopathy and impaired corneal sensitivity exists. CONCLUSIONS:: This research identified the presence of visible keratopathy in 80% of eyes. In addition, 26% of eyes had a keratopathy level that caused visual disturbances. The study showed that the prevalence and severity of keratopathy increased with the patient's age. Further conclusions are that intraocular surgery increases the severity of keratopathy and that the severity of keratopathy is correlated to reduced corneal sensitivity. Finally, extreme care should be taken when selecting patients for intraocular surgery because this procedure can trigger the development of keratopathy

Epidemiology of aniridia in Sweden and Norway.

Purpose: To investigate the epidemiology of aniridia in the populations of Sweden and Norway. Methods: A thorough search for aniridia patients has been performed in Sweden and Norway. All participants had a clinical ophthalmological examination documented through photography. Blood samples were taken for mutation analysis and pedigrees were established. Results: A total of 181 patients with aniridia were identified in the two countries. This gives an age-specific prevalence of 1:72 000 in the entire region, 1:70 000 in Sweden and 1:76 000 in Norway. A total of 124 individuals (69%) were examined. Male/female ratio was 0.94 (Sweden 0.85 and Norway 1.2). Mean age of the examined patients was 29 years and median age 25 years. We did not find any significant age difference between the two countries. The mean visual acuity (VA) was 0.19 (Sweden 0.19 and Norway 0.18).The number of families with more than one affected member was 31 and the number of sporadic cases was 40. Conclusion: We have done a thorough search of the literature, but we have found no earlier studies describing aniridia in an entire country and only a few reports from larger areas. We assume that most aniridia patients have been found and the aniridia prevalence of 1:72 000 can be regarded as well supported. Further studies on other aspects of aniridia are in progress, and information from these can contribute to guidelines for the care of patients with this rare but serious disease

Aniridia among children and teenagers in Sweden and Norway.

Purpose: To investigate patients under the age of 20 with aniridia in Sweden and Norway in order to estimate the prevalence of aniridia, to describe clinical signs and identify complications in the young, which will help improve diagnostic tools and treatment. Methods: A thorough search for patients with aniridia (of all ages) was performed. Sixty-two of the 181 patients were under the age of 20. Fifty-two of them were examined and they constituted the study population. Patient history was obtained and all participants underwent clinical ophthalmologic examination, including photography. Blood samples were taken for mutation analysis. Results: Epidemiological data are only based on the results in Sweden. The age-specific prevalence in Sweden was 1:47 000, male/female ratio was 0.57, mean age 12 years and median age 14 years. The proportion of sporadic cases including WAGR (Wilms tumour, Aniridia, Genitourinary abnormalities, Mental Retardation) and Gillespie syndrome (aniridia, cerebellar ataxia and mental retardation) was 48%. In the entire study population (Sweden and Norway), the mean visual acuity (VA) was 0.2 (range 0.04-0.9). We found VA < 0.3 in 80% and <0.1 in 18% of the patients. Twenty-two patients (42%) had one or more of the sight threatening complications such as cataract/lens luxation, corneal clouding or glaucoma. Conclusion: Descriptions of aniridia in the younger are rare. This study shows that aniridia seems to be more common than previously estimated and that some complications appear early in life. Watchfulness as regards these complications and regular examinations are essential even in the youngest