Analysis of age at detection and outcomes of dense unilateral congenital cataract surgery for children on the paediatric cataract register.

AIM: Analysis of age at time of detection and surgery of dense unilateral cataract and investigation of best-corrected visual acuity (BCVA) in a nationwide register-based cohort study, based on the routine of maternity ward eye screening. METHODS: Data were derived from the Paediatric Cataract Register (PECARE). All children (n = 54) diagnosed with dense congenital unilateral cataract between January 2007 and September 2014 who had surgery before 1 year of age, and for whom 5-year follow-up records were available, were included. RESULTS: The majority, 35/54 (65%), were detected and operated on before age 6 weeks and 30/35 (86%) were referred from maternity wards. Visual acuity (VA) ≥ 0.5 (decimal, 0.3 logMAR) was found in 7/53 (13%) of the cohort at age 5 years; further, 19 children achieved VA ≥ 0.1 (decimal, 1.0 logMAR) (36%) and 19 children VA < 0.05 (decimal, 1.30 logMAR) (36%). Ten-year follow-up records were available for 17/53 (32%) children; 1/17 (6%) achieved VA ≥ 0.5 (decimal, 0.3 logMAR), 4/17 (24%) VA ≥ 0.3-<0.5 (decimal, 0.52-0.30 logMAR), 3/17 (18%) VA ≥ 0.05-0.1 (decimal, 1.30-1.0 logMAR) and 10/17 (59%) VA < 0.05 (decimal, 1.30 logMAR). CONCLUSION: A total of 90% of the children were detected with cataract within 100 days of birth and 80% were operated on within this period. This study showed better visual acuity in those treated for dense unilateral cataracts than previously reported in an earlier Swedish cohort study.

Adrenal Suppression in Infants Treated with Topical Ocular Glucocorticoids.

PURPOSE: To analyze the incidence of adrenal suppression and the glucocorticoid (GC) dose per kilogram body weight given in infants treated with standard protocol for topical ophthalmic GCs after congenital cataract surgery. DESIGN: Retrospective, consecutive case series. PARTICIPANTS: All children younger than 2 years of age who underwent operation for congenital cataract between January 2011 and May 2015 in 1 center. METHODS: Patient charts were reviewed to collect data on results and timing of a standard corticotropin (adrenocorticotropic hormone [ACTH]) stimulation test and GC dose per kilogram body weight. MAIN OUTCOME MEASURES: Incidence of adrenal suppression in children tested on GC treatment. Glucocorticoid dose per kilogram body weight. RESULTS: Among 26 consecutive infants, 15 (58%) were tested while they were still on GC treatment. Ten of these 15 infants (67%) had adrenal suppression, 2 of whom had obvious clinical signs of Cushing's syndrome and 1 of whom had signs of Addisonian crises during general anesthesia. Eleven of the 26 infants (42%) were tested at a median time of 21 days (range, 6-89) after treatment cessation, and they all had normal test results. Children with suppressed adrenal function had received cumulative GC doses per body weight that were significantly higher the last 5 days before testing compared with children with normal test results. Infants with adrenal suppression were treated with hydrocortisone replacement therapy. Adrenal function recovered after a median of 3.1 months (range, 2.3 months to 2.3 years). CONCLUSIONS: Two thirds of the infants tested during treatment with a standard GC protocol after congenital cataract surgery showed adrenal suppression. There was a significant association between the cumulative daily dose of GCs and the test result. Because adrenal suppression is a serious but treatable condition, we recommend a systematic assessment of adrenal function in infants treated with doses of topical ocular GCs comparable to our regimen and careful evaluations of other treatment regimens.

The Effect of Cataract Surgery on Circadian Photoentrainment: A Randomized Trial of Blue-Blocking versus Neutral Intraocular Lenses.

PURPOSE: Cataract decreases blue light transmission. Because of the selective blue light sensitivity of the retinal ganglion cells governing circadian photoentrainment, cataract may interfere with normal sleep-wake regulation and cause sleep disturbances. The purpose was to investigate the effect of cataract surgery on circadian photoentrainment and to determine any difference between blue-blocking and neutral intraocular lenses (IOLs). DESIGN: The study was a single-center, investigator-driven, double-masked, block-randomized clinical trial. PARTICIPANTS: One eye in 76 patients with bilateral age-related cataract eligible for cataract surgery was included. METHODS: Intervention was cataract surgery by phacoemulsification. Patients were randomized to receive a blue-blocking or neutral IOL. MAIN OUTCOME MEASURES: Primary outcome was activation of intrinsic photosensitive ganglion cells using post-illumination pupil response (PIPR) to blue light from 10 to 30 seconds after light exposure as a surrogate measure. Secondary outcomes were circadian rhythm analysis using actigraphy and 24-hour salivary melatonin measurements. Finally, objective and subjective sleep quality were determined by actigraphy and the Pittsburgh Sleep Quality Index. RESULTS: The blue light PIPR increased 2 days (17%) and 3 weeks (24%) after surgery (P < 0.001). The majority of circadian and sleep-specific actigraphy parameters did not change after surgery. A forward shift of the circadian rhythm by 22 minutes (P = 0.004) for actigraphy and a tendency toward an earlier melatonin onset (P = 0.095) were found. Peak salivary melatonin concentration increased after surgery (P = 0.037). No difference was detected between blue-blocking and neutral IOLs, whereas low preoperative blue light transmission was inversely associated with an increase in PIPR (P = 0.021) and sleep efficiency (P = 0.048). CONCLUSIONS: Cataract surgery increases photoreception by the photosensitive retinal ganglion cells. Because of inconsistency between the significant findings and the many parameters that were unchanged, we can conclude that cataract surgery does not adversely affect the circadian rhythm or sleep. Longer follow-up time and fellow eye surgery may reveal the significance of the subtle changes observed. We found no difference between blue-blocking and neutral IOLs, and, because of the minor effect of surgery in itself, an effect of IOL type seems highly unlikely.

The prevalence of visual axis opacification in the Swedish Pediatric Cataract Register.

PURPOSE: To report on the occurrence of postoperative visual axis opacification (VAO) in children younger than 5 years of age operated for cataract in Sweden, and to analyse correlations with age at surgery and surgical method. METHODS: Data were derived from the Swedish Pediatric Cataract Register (PECARE). All children operated on between 1 January 2007 and 31 December 2020 were included. Follow-ups at 1, 2 and 5 years of age were analysed. RESULTS: Cataract surgery were performed on 770 eyes belonging to 549 children (n = 282 boys, 51.4%); 327/770 (42.5%) of the children underwent surgery before 3 months of age and 216/770 (28%) before 6 weeks of age. Data on 881 follow-up visits were registered. At the follow up-visits at 1, 2 and 5 years of age, VAO was present in 154/349 (44.1%), 41/323 (12.7%) and 25/208 (12%). The majority of the children with VAO underwent cataract surgery before age 6 months, with a predominance before age 2 months. Primary IOL was implanted in 601/770 (78%) of eyes; 40.8% had an acrylic one-piece lens, 31.8% had a bag-in-the-lens IOL, 21.9% were aphakic and 5.2% had an acrylic three-piece lens. Implantation of a bag-in-the-lens IOL was related to a significantly lower occurrence of VAO compared to other types of IOL, including aphakia (p < 0.0002). CONCLUSION: Our results are in accordance with the literature. Primary bag-in-the-lens IOL implantation before 2 years of age seems adequate and safe, with a low occurrence of VAO, and can thus be continued as routine in Sweden.

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

AIM: 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. METHODS: Surveys were sent in 2006 to maternity/neonatal and women's health departments regarding screening policy. Response frequency was 96% (122/127). Data were derived from the Paediatric Cataract Register (PECARE), Sweden. All Swedish children diagnosed with congenital cataract and operated on before 1 year of age between January 2007 and December 2009 were included. Statistical comparison with earlier retrospective results was performed. RESULTS: Eye screening is a routine protocol at a rate of 90% of Swedish maternity wards. Sixty-one children were included in the study. An increase was shown in case referrals from maternity wards compared to 10 years ago (64% vs. 50%). Detection was performed within 6 weeks of age in 75% of the cases. A significant difference between the probabilities of early referral (0.38; p < 0.001, < 6 weeks of age) and early surgery (0.36; p < 0.001) (PECARE) was found in comparison with the historical data of no maternity-ward screening. Well-baby clinics were instrumental in early detection, as well. CONCLUSION: Eye screening in maternity wards is effective. Clear Swedish directives are to be preferred.

PECARE: Parental Feedback to Improve Congenital Cataract Care in Sweden.

PURPOSE: To analyze non-directed parental feedback to health care providers responsible for pediatric cataract care in Sweden. METHODS: A directed content analysis was used to analyze data consisting of text representing free comments provided by 40 parents. A deductive approach was employed by applying the model of balancing the child's inability and ability, which includes the categories mastering, collaborating, facilitating, and adapting. RESULTS: Parents lacked piloting and self-management support. They experienced an absence of partnership with the health care team and not being taken seriously. They also felt abandoned by health care, resulting in emotional distress. Parents highlighted the impact of their social network and the challenges involved in accepting and adapting to the changes in everyday life. CONCLUSIONS: This study emphasizes the consequences of the lack of a caring partnership with health care professionals. Because parents act as mediators of care to the child with congenital cataract, persistence on the part of parents and a family-centered approach are essential for the child's visual development. [J Pediatr Ophthalmol Strabismus. 2023;60(4):298-294.].

In-utero exposure to smoking, alcohol, coffee, and tea and risk of strabismus.

In a prospective, population-based cohort study, the authors investigated the effect of in-utero exposure to maternal smoking and consumption of alcohol, coffee, and tea on the risk of strabismus. They reviewed medical records for children in the Danish National Birth Cohort identified through national registers as possibly having strabismus. Relative risk estimates were adjusted for year of birth, social class, maternal smoking, maternal age at birth, and maternal coffee and tea consumption. The authors identified 1,321 cases of strabismus in a cohort of 96,842 Danish children born between 1996 and 2003. Maternal smoking was associated with a significantly elevated risk of strabismus in the child, increasing with number of cigarettes smoked per day (<5 cigarettes/day: relative risk (RR) = 0.95, 95% confidence interval (CI): 0.80, 1.14; 5-<10 cigarettes/day: RR = 1.38, 95% CI: 1.12, 1.70; > or =10 cigarettes/day: RR = 1.90, 95% CI: 1.57, 2.30). Nicotine replacement therapy was not associated with strabismus risk (RR = 1.22, 95% CI: 0.92, 1.61). Light maternal alcohol consumption was inversely associated with strabismus risk, whereas maternal coffee and tea drinking were not associated with strabismus risk. In conclusion, smoking during pregnancy is associated with an increased risk of strabismus in the offspring. Conversely, light alcohol consumption is associated with decreased risk.

The Swedish National Pediatric Cataract Register (PECARE): incidence and onset of postoperative glaucoma.

PURPOSE: The aim was to report cumulative incidence and time of onset of postoperative glaucoma in a paediatric early cataract surgery cohort. METHODS: Data were retrieved from the Pediatric Cataract Register (PECARE), a prospective register of Swedish cataract operations before 8 years of age. All eyes with surgery between January 2007 and December 2014 and a registered follow-up were included. Cataracts caused by uveitis, trauma or coexisting congenital glaucoma were excluded. Glaucoma was defined as early onset if diagnosed within a year after surgery and late onset if diagnosed later. RESULTS: The study included 288 eyes in 207 children (106 girls), 81 with bilateral and 126 with unilateral cataracts, with a mean follow-up of 3.31 ± 1.77 years. Of the 288, 168 (58.3%) had surgery before 3 months of age; most of these 92.3% (155/168) were defined as dense, 208 (72.2%) were below 1 year of age. Cumulative incidence of surgically treated glaucoma among individuals was 23.7% (49/207). Median time to glaucoma onset was 0.91 years (range: 0.05-4.97 years) for eyes. Early-onset glaucoma was found in 98 % (63/64), and late onset in 2% (1/64). CONCLUSION: In this paediatric cataract cohort, a majority of eyes had surgery before 3 months of age (58.3%). Secondary glaucoma-onset peaked within the first postoperative year, with a cumulative incidence of 23.7%. Surgery performed after the first month of life, resulted in a lower glaucoma rate. Long-term follow-up will reveal whether the low rate of late-onset glaucoma with early surgery will last, and if so, the consequences.

Risk of glaucoma after pediatric cataract surgery.

PURPOSE: To determine the risk of glaucoma after surgery for pediatric cataract and to evaluate risk factors for glaucoma. METHODS: A population-based cohort of all children in Denmark aged 0 to 17 years during the period 1977 to 2001, who underwent surgery for pediatric cataract, was established by retrospective chart review. Glaucoma cases were defined as those in which glaucoma surgery (trabeculectomy and/or diode laser transscleral cyclophotocoagulation) was performed and/or permanent medical therapy prescribed after cataract surgery. RESULTS: Of 946 eyes (595 patients) undergoing pediatric cataract surgery, 72 eyes (48 patients) had subsequent development of glaucoma. Early surgery (<9 months of age) was associated with a 7.2-fold increased risk of glaucoma compared with late surgery (> or =9 months of age). Ten years after cataract surgery, glaucoma developed in 31.9% (95% confidence interval [CI], 24.4-41.1) of children undergoing surgery before 9 months of age compared with 4.1% (95% CI, 2.4 to 6.8) of children aged > or =9 months at the time of surgery. Glaucoma cases continued to occur more than 10 years after cataract surgery. After adjustment for age at surgery, no other risk factor appeared important. CONCLUSIONS: The risk of glaucoma after surgery for pediatric cataract is substantial and particularly high for those below 9 months of age at the time of surgery. Because the increased risk persists for many years after surgery, careful continuous monitoring for glaucoma is mandatory.

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

AIM: To report basic epidemiological data concerning surgically treated childhood cataract in Sweden and Denmark. METHODS: Data were derived from the Paediatric Cataract Register (PECARE), a binational, web-based surgical register representing Sweden and Denmark. All children operated before 8 years of age between 1 January 2007 and 31 December 2013 were included. Age-specific prevalence per 100 000 population was calculated. RESULTS: A total 574 operations in 213 boys (51.7%) and 199 girls (48.3%), altogether 412 children, were registered, the vast majority (n = 395/412; 95.9%) being individuals with congenital/infantile cataract. Of these 412, a total of 294 (147 boys and 147 girls) were Swedish and 118 (66 boys and 52 girls) were Danish. The age-specific prevalence of operated cataract in Sweden was 31/100 000 and in Denmark 28/100 000. In 454 of 574 eyes (79.1%), the cataract was dense. Altogether, 266 of 574 (46.3%) were operated during the first year of life, 193 during the first 12 weeks representing 33.6% of all operations. A primary intraocular lens (IOL) implantation was done in altogether 411 of 574 eyes (71,6%). In total, 210 unilateral cataract operations (210/574; 36.6%) were performed. Persistent fetal vasculature (PFV) was present in 64 of 193 (33.1%) of those with a congenital unilateral cataract. In 84 individuals (84/395; 21.3%) with congenital or infantile cataract, a coexisting disorder was found. CONCLUSION: The age-specific binational prevalence of operated congenital/infantile cataract in Sweden and Denmark is 30/100 000. About half of the operations are performed within the first year of life, one-third within the first 3 months. In our study population, a primary IOL was implanted in the majority of cases.

The effect of blue-blocking and neutral intraocular lenses on circadian photoentrainment and sleep one year after cataract surgery.

PURPOSE: To compare the long-term effect on circadian photoentrainment and sleep in patients implanted with neutral and blue-blocking intraocular lenses 1 year after cataract surgery. METHODS: Randomized, controlled trial involving 67 patients with age-related cataract. Intervention was cataract surgery with implantation of either a neutral or a blue-blocking intraocular lens (IOL). Main outcome was activation of the intrinsically photosensitive retinal ganglion cells (ipRGC) measured by chromatic pupillometry. The circadian rhythm was analysed by 24-hr melatonin profiles and actigraphy; the latter was also used to determine objective sleep quality. The Pittsburgh Sleep Quality Index determined subjective sleep quality. RESULTS: One year after surgery, peak melatonin concentration was 3.3 pg/ml (95% CI, 2-5.5) corresponding to 50% lower for the participants allocated to blue-blocking IOLs compared with participants allocated to neutral IOLs. Compared with preoperative levels, the ipRGC response had increased by 13.7% (95% confidence interval [CI], 3.2-22.6) 1 year after surgery. Objective sleep quality was also improved as the time of wakefulness after sleep onset had improved by 5 min (95% CI, 1-10) for the entire population while sleep efficiency had increased by two percentage points (95% CI, 0.42-3.65) although exclusively, for the participants allocated to blue-blocking IOLs. CONCLUSION: Blue-blocking IOLs increased sleep efficiency but lowered nocturnal melatonin secretion compared with neutral IOLs. Cataract surgery improved the response of ipRGCs and sleep quality. However, the effect of cataract surgery on sleep quality may be unrelated to circadian photoentrainment.

Strabismus Incidence in a Danish Population-Based Cohort of Children.

Importance: To our knowledge, there have been few population-based studies of strabismus incidence conducted. Our population-based study provides valuable data for health services planning and identifying research needs. Objective: To determine the incidence and age distribution of strabismus, overall and by subtype, among children 7 years or younger. Design, Setting, and Participants: This population-based cohort study was conducted with data from 96 842 children enrolled in the Danish National Birth Cohort. Main Outcomes and Measures: Age-specific incidence and cumulative incidence and median age at the detection of strabismus, overall and by subtype. Results: The study cohort included 96 842 children born between 1996 and 2008 who are predominantly Caucasian and is composed of approximately 30% of births in Denmark, with a boy-girl ratio of 51:49. Overall, 1309 cases of strabismus were identified in the cohort. We found an overall cumulative strabismus incidence of 2.56% (95% CI, 2.42-2.69) at 7 years. The overall incidence was similar among boys and girls. Two hundred sixteen participants (16.5%) (95% CI, 14.5-18.6) had congenital esotropia, 177 (13.5%) (95% CI, 11.7-15.5) had fully accommodative esotropia, 252 (19.3%) (95% CI, 17.1-21.5) had partially accommodative esotropia, and 181 (13.8%) (95% CI, 12.0-15.8) had exotropia. The esotropia:exotropia ratio was 5.4:1 (95% CI, 3.4:1 to 7.5:1). Age-specific incidence curves for congenital esotropia, fully accommodative esotropia, partially accommodative esotropia, and all exotropia revealed interactions between strabismus subtype and age, suggesting that the different subtypes had different age-specific patterns of incidence (P < .001 for all comparisons between pairs of curves). The median age at detection for the 4 subtypes was 0, 32.0, 26.1, and 16.6 months, respectively. Conclusions and Relevance: In a national, population-based cohort study, we found a cumulative incidence of strabismus consistent with those reported in smaller European and American cohorts, but a somewhat higher esotropia:exotropia ratio than those that, to our knowledge, are typically reported by English and American studies. Patterns of incidence by age differed for different strabismus subtypes, indicating differences in age at onset and thereby implying differences in the underlying etiology.

Risk factors for idiopathic congenital/infantile cataract.

PURPOSE: To investigate maternal, demographic, and pre- and perinatal risk factors for idiopathic congenital/infantile (ICI) cataract. METHODS: Based on national registries, a cohort of all children born in Denmark and aged 0 to 17 years during 1977 to 2001 was established, and congenital/infantile cataract cases were identified. Cases of unknown/idiopathic cause were included in the study. Associations between maternal, demographic, and pre- and perinatal factors with the development of cataract were investigated. RESULTS: In a cohort of 2.9 million children, 1027 cases of congenital/infantile cataract were identified. Of the children in those cases, 629 were born in Denmark and had ICI. Bilateral isolated cataract cases were male dominated (62%; 95% confidence interval [CI], 56%-69%) but not unilateral isolated cases (40%; 95% CI, 34%-47%). Older age (> or =40 years) of mothers at delivery and caesarean section increased the risk of ICI cataract. Low birth weight (< 2000 g) was associated with a 10.6-fold (95% CI, 6.99-16.10) increased risk of bilateral, but not unilateral, ICI cataract. No significant associations were found with birth order, month/place of birth, or cigarette smoking during pregnancy. CONCLUSIONS: Variables indicative of environmental influence were not associated with ICI cataract. Low-birth-weight children (< 2000 g) had a significantly increased risk of bilateral ICI, whereas no strong risk factors were found for unilateral cataract. Together with the sex difference, this suggests that the etiologies of bilateral and unilateral cataract are different.

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

PURPOSE: To analyse and discuss screening for the detection of congenital cataract in two Nordic countries, Denmark and Sweden. METHODS: Until 2011, in Denmark, no guideline concerning screening for congenital cataract existed. Since 2011, Danish guidelines regarding eye examination include examination with a pencil light at age 5 weeks, whereas newborn red reflex examination using a handheld ophthalmoscope is routine protocol in Swedish maternity wards. Data regarding age of referral were derived from the Pediatric Cataract Register (PECARE). All children operated on before 1 year of age between January 2008 and December 2012 were included. Statistical comparison of the different screening strategies was made. RESULTS: The number of children undergoing surgery for congenital cataract before 1 year of age was 31 (17 bilateral cases) in Denmark and 92 (38 bilateral cases) in Sweden. The proportion was 14 per 100.000 children in Denmark and 16 in Sweden (p < 0.05). There was a statistically significant difference between Denmark and Sweden in the percentage of children referred within 42 days of birth (p < 0.0001) and within 100 days (p < 0.001). CONCLUSION: Due to the screening procedure with red reflex examination, congenital cataract in Swedish children is detected significantly earlier than in Danish children.

Incidence and cumulative risk of childhood cataract in a cohort of 2.6 million Danish children.

PURPOSE: To determine the incidence and cumulative risk of childhood cataract in Denmark during 1980 to 2000. METHODS: A cohort of 2,616,439 Danish children born between 1962 and 2000 was followed from 1980 or from the day of birth, whichever occurred later, until their 18th birthday, death, emigration, or diagnosis of cataract, whichever occurred first. Cases were ascertained from the Danish National Register of Patients (NRP) and validated by reviewing the medical records. They were divided into four groups: congenital/infantile (CI) cataract, traumatic cataract, complicated cataract, and "other" types of cataract. RESULTS: After diagnostic validation, 1311 children with cataract (59% with CI cataract) were included in the study. During 1995 to 2000 the overall cumulative risk of childhood cataract was 108.4 per 100,000 children. There was no significant difference in incidence between girls and boys or over time (1980 to 2000) for CI, complicated, and "other" types of cataract. In contrast, the incidence of traumatic cataract was significantly higher among boys. It remained increased during the entire study period despite a 23% decrease per 5 years among boys. Sixty-six percent of the children diagnosed with CI cataract below 2 years of age underwent surgery within 1 year. CONCLUSIONS: The stable incidence during a 20-year period of CI cataract and complicated cataract indicates that risk factors for these conditions have remained unchanged, whereas the marked drop of traumatic cataract among boys most likely reflects changed behavior and an increased focus on preventive measures.

A nationwide Danish study of 1027 cases of congenital/infantile cataracts: etiological and clinical classifications.

OBJECTIVE: To study the distribution of congenital/infantile cataract in the entire population of Denmark according to etiological and clinical classifications. DESIGN: Population-based cohort study with retrospective chart review. PARTICIPANTS: All children (0 to 17 years old) who were born between 1959 and 2001 and registered with congenital/infantile cataract in Denmark during the period 1977 to 2001. Cases were ascertained from the mandatory Danish National Register of Patients, and all medical records were reviewed. METHODS: Etiological and clinical classifications of the cataract cases were based on information from the medical records. MAIN OUTCOME MEASURES: Classification of congenital/infantile cataract according to presumed etiology; gender; clinical appearance, including laterality and morphology; and the time trends according to etiology and laterality. RESULTS: A total of 1027 children with congenital/infantile cataract, 529 boys and 498 girls, were included, of whom 64% were bilateral. Males predominated with bilateral cataract, whereas females predominated with unilateral cases. Isolated cataract was the most frequent clinical presentation (71% of all cases), followed by an even proportion of cataract associated with additional ocular dysmorphology and cataract associated with systemic anomalies. Almost two thirds of all cases had an unknown etiology (idiopathic). Idiopathic cases showed a higher proportion of unilateral cataract and of additional ocular dysmorphology compared with cases of known etiology. The etiology was unknown in 87% of unilateral cases and in 50% of bilateral cases. The distribution by presumed etiology was stable during the study period, except for cataract caused by maternal infections, which decreased mainly due to the elimination of congenital rubella. CONCLUSIONS: With the exception of the decline of congenital rubella, the proportion of congenital/infantile cataract cases of unknown, genetic, and infectious origins has been stable since the late 1970s. The causes of 87% of unilateral cataracts and 50% of bilateral congenital/infantile cataracts remain unknown, making the prevention of the disease a continuing challenge.

Human parallels to experimental myopia? A literature review on visual deprivation.

Raviola and Wiesel's monkey eyelid suture studies of the 1970s laid the cornerstone for the experimental myopia science undertaken since then. The aim has been to clarify the basic humoral and neuronal mechanisms behind induced myopization, its eye tissue transmitters in particular. Besides acquiring new and basic knowledge, the practical object of the research is to reduce the burden of human myopia around the world. Acquisition and cost of optical correction is one issue, but associated morbidity counts more, with its global load of myopia-associated visual loss and blindness. The object of the present PubMed literature-based review is to evaluate apparent similarities between experience from disturbed imaging in experimental laboratory science and varieties within the spectrum of childhood human myopia. So far, the main impression is that macroscopical optical deprivation appears absent in the prevalent types of human myopia, nor is myopia a regular sequel where early eye pathology has led to poor imaging and optical deprivation. Optical aberrations of a higher order are a relatively new issue in myopia research, and microstructural deprivation is only marginally dealt within the survey. Links between experimental and human myopia appear mainly occasional, and with only few examples in humans where factual parallels appear credible. Clinical and epidemiological data on refraction remain important, in particular with a view to life style and environmental factors. Such knowledge may further serve as inspiration to the laboratory research, which aims at solving the basic enigmas on a tissue level.

Risk of retinal detachment after pediatric cataract surgery.

PURPOSE: To determine the long-term risk of retinal detachment following pediatric cataract surgery and to identify risk factors for retinal detachment. METHODS: We included all children (aged 0 to 17 years) who during the time period of 1977 to 2005 underwent pediatric cataract surgery in Denmark, excluding cataract cases caused by trauma, or acquired systemic or acquired ocular pathology, and cases with ocular anomalies associated with the development of retinal detachment. Cases of cataract were ascertained from the mandatory Danish National Patient Register, and information on retinal detachment was based on medical chart review. RESULTS: Among 1043 eyes of 656 children undergoing surgery for pediatric cataract, 25 eyes (23 children) developed retinal detachment at a median time of 9.1 years after surgery. The overall 20-year risk of retinal detachment was 7% (95% confidence interval [CI]: 3%-11%) among cataract patients. In otherwise normal children having isolated cataract, the risk was 3% (95% CI: 0%-7%). A significantly higher risk of developing retinal detachment was found in children with mental retardation (23% [95% CI: 9%-35%]) or in cataract cases with other ocular or systemic anomalies (16% [95% CI: 6%-24%]). CONCLUSIONS: The estimated overall risk of retinal detachment 20 years after pediatric cataract surgery was 7%, but only 3% for isolated cataract. Particularly high risks of retinal detachment after cataract surgery were associated with mental retardation and having other ocular or systemic diseases.

Perinatal risk factors for strabismus.

BACKGROUND: Little is known about the aetiological factors underlying strabismus. We undertook a large cohort study to investigate perinatal risk factors for strabismus, overall and by subtype. METHODS: Orthoptists reviewed ophthalmological records for Danish National Birth Cohort (DNBC) children examined for strabismus in hospital ophthalmology departments or by ophthalmologists in private practice. Information on perinatal characteristics was obtained from national registers. We used log-linear binomial regression and polytomous logistic regression to estimate risk ratios for strabismus overall and by strabismus subtype, respectively. RESULTS: Among 96,842 DNBC children born in Denmark between 1996 and 2003, we identified 8783 children who had been evaluated for strabismus. Ophthalmological records were available for 5655 of these children, of whom 1321 were diagnosed with strabismus. In multivariable analysis, low birth weight, prematurity, large head circumference and presence of congenital abnormalities were all associated with increased risk of strabismus. Presence of congenital abnormalities was more strongly associated with exotropia than with esotropia. Of 183 exotropia cases, 40 (22%) had congenital abnormality. Although not associated with esotropia, delivery by Caesarean section was associated with exotropia (relative risk = 1.65; 95% confidence interval 1.16-2.34). After adjustment for birth weight, Apgar score at 5 min, multiple gestation and parental ages were not associated with strabismus overall. CONCLUSIONS: Congenital abnormalities, low birth weight, prematurity and large head circumference were independent risk factors for strabismus. Differences in risk factors for esotropia and exotropia suggest that strabismus subtypes may have different underlying aetiologies. The proportion of exotropic children with congenital abnormalities suggests that a large angle constant exotropia in an infant should alert physicians to the possibility of a congenital abnormality.