Incidence of ocular pathologies in Italian children with Down syndrome

Prevalence and etiology of strabismus in Down syndrome: A systematic review and meta-analysis with a focus on ethnic differences in the esotropia/exotropia ratio

Purpose

We sought to determine the prevalence of strabismus and the esotropia/exotropia ratio in Down syndrome. Wide ranges of an increased strabismus prevalence have been reported and it is unclear by how much esotropia exceeds exotropia in people with Down syndrome.

Methods

We compiled in a systematic review and meta-analysis the results of over 100 studies that report the strabismus prevalence and ratio of esotropia/exotropia in cohorts of Down syndrome. We calculated the pooled global prevalence and established the geographical distribution of the strabismus prevalence and the esotropia/exotropia ratio.

Results

The ethnically-adjusted global prevalence of strabismus in Down syndrome is 30.2%. In subjects 15 years and older, the global prevalence is 53.2%, and the lifetime prevalence is 51.0%. In populations which normally have more esotropia than exotropia (e.g., Caucasians), Down syndrome subjects have a further increased bias towards esotropia. In populations which normally have more exotropia (e.g., West Africans, Asians and Hispanics), Down syndrome subjects have a significantly lower esotropia/exotropia ratio (3.21) than reported in Caucasians with Down syndrome (9.98).

Conclusion

Worldwide, about 1.81 million people with Down syndrome have strabismus: 1.42 million of them have esotropia, and 0.37 million have exotropia. Differences in the esotropia/exotropia ratio between ethnicities point to the orbital anatomy as a major contributing factor to the etiology of strabismus in Down syndrome. The narrow-set eyes (reduced orbital width) in Down syndrome favor esotropia over exotropia, especially in Caucasians, thus explaining why Down syndrome patients from different ethnicities have different prevalences of esotropia and exotropia.

The Secondary Childhood Glaucomas

The secondary childhood glaucomas are a heterogenous group, often associated with other ocular or systemic abnormalities. These childhood glaucomas are distinct from primary childhood glaucomas, both in terms of their clinical features and their response to conventional treatment. Surgical management can be challenging in children with secondary glaucoma. On average, this group undergo more surgical procedures and revisions than those with primary congenital glaucoma. We provide a synopsis of secondary childhood glaucomas in terms of classification, clinical features, and management strategies, with emphasis on recent developments.

Pediatric keratoconus

Keratoconus is a common pediatric corneal disease, leading to vision impairment and amblyopia. Compared to its adult counterpart, pediatric keratoconus has an advanced presentation, rapid progression, higher incidence of complications such as corneal hydrops, and greater potential impact on the quality of life. It typically manifests during puberty and can evolve rapidly to more severe stages if left untreated. This rapid progression underscores the importance of early diagnosis through regular screening in pediatric populations and vigilant monitoring of pediatric keratoconus suspects. Concomitant ocular allergies, ocular anomalies, systemic diseases (e.g. syndromes), and poor compliance with contact lenses might impede prompt intervention and frequently postpone rehabilitation. Corneal collagen crosslinking is a crucial intervention in the management of pediatric keratoconus because it strengthens the corneal microstructure and halts the disease progression. When conservative measures fail, keratoplasty remains a viable option with generally favorable outcomes, though with unique challenges in post-operative care, including concerns related to sutures, long-term graft survival and need for repeated examinations under anesthesia. A multidisciplinary approach involving ophthalmologists, optometrists, pediatricians, and other healthcare professionals, focusing on early diagnosis and timely intervention, is essential for the comprehensive management of pediatric keratoconus and to mitigate its impact on children's lives.

Ophthalmologic and neuro-ophthalmologic findings in children with Down syndrome

Down syndrome, also known as Trisomy 21, is a genetic disorder associated with mild-to-moderate intellectual disability, delays in growth, and characteristic facial features. A wide range of ocular complications are seen in children with Down syndrome, including strabismus, nystagmus, refractive errors, congenital cataracts, the presence of keratoconus, and decreased visual acuity. Early ophthalmic examination is needed for early diagnosis and treatment in patients. This narrative review examines ocular manifestations in children with Down syndrome and the importance of prompt ophthalmic interventions for treatment.

Systemic Associations with Keratoconus

Keratoconus is a disease of the cornea that results in progressive steepening and thinning of the cornea and subsequent vision loss. It nearly always presents as a bilateral disease, suggesting that there is an underlying abnormality of the corneas that becomes manifest with time. However, the mechanisms underlying the development of keratoconus are largely unknown. Associations reported between keratoconus and systemic diseases are abundant in the literature, and the list of possible associations is very long. We found that atopy, Down syndrome, and various connective tissue diseases were the most frequently cited associations in our broad literature search. Additionally, Diabetes Mellitus has been increasingly studied as a possible protective factor against keratoconus. In this review, we have summarized the evidence for and against these particular systemic conditions and keratoconus and have discussed some of the implications of keratoconus patients having these conditions.

The Ophthalmic Manifestations of Down Syndrome

Down Syndrome is one of the most common chromosomal conditions in the world, affecting an estimated 1:400-1:500 births. It is a multisystem genetic disorder but has a wide range of ophthalmic findings. These include strabismus, amblyopia, accommodation defects, refractive error, eyelid abnormalities, nasolacrimal duct obstruction, nystagmus, keratoconus, cataracts, retinal abnormalities, optic nerve abnormalities, and glaucoma. These ophthalmic conditions are more prevalent in children with Down Syndrome than the general pediatric population, and without exception, early identification with thoughtful screening in this patient population can drastically improve prognosis and/or quality of life.

The Underlying Relationship between Keratoconus and Down Syndrome

Keratoconus (KC) is one of the most significant corneal disorders worldwide, characterized by the progressive thinning and cone-shaped protrusion of the cornea, which can lead to severe visual impairment. The prevalence of KC varies greatly by ethnic groups and geographic regions and has been observed to be higher in recent years. Although studies reveal a possible link between KC and genetics, hormonal disturbances, environmental factors, and specific comorbidities such as Down Syndrome (DS), the exact cause of KC remains unknown. The incidence of KC ranges from 0% to 71% in DS patients, implying that as the worldwide population of DS patients grows, the number of KC patients may continue to rise significantly. As a result, this review aims to shed more light on the underlying relationship between KC and DS by examining the genetics relating to the cornea, central corneal thickness (CCT), and mechanical forces on the cornea, such as vigorous eye rubbing. Furthermore, this review discusses KC diagnostic and treatment strategies that may help detect KC in DS patients, as well as the available DS mouse models that could be used in modeling KC in DS patients. In summary, this review will provide improved clinical knowledge of KC in DS patients and promote additional KC-related research in these patients to enhance their eyesight and provide suitable treatment targets.

Systemic and Ophthalmic Manifestations in Different Types of Refractive Errors in Patients with Down Syndrome

Background and Objective: This study aims to investigate the prevalence of systemic and ophthalmic manifestations in different refractive groups in children and young adults with Down syndrome (DS). Materials and Methods: The study was a population-based, cross-sectional study that included 141 Caucasian children and young adults with DS. They were classified into the following three groups: myopia DS group (37 subjects, mean age 15.8 years), emmetropia DS group (41 subjects, mean age 11.7 years) and hyperopia DS group (63 subjects, mean age 10.9 years). The participants underwent inspection, slit-lamp examination, cycloplegic refraction, ocular alignment and ocular motility examination. Ten systemic manifestations were analyzed. Results: There was no difference in the prevalence of any systemic manifestations between the groups. Considering the ophthalmic manifestations, there was statistical difference in the distribution of proportions among the three groups for nystagmus (p = 0.011), iris-stromal atrophy (p = 0.048) and strabismus (p = 0.031). The prevalence of strabismus in our DS myopia group was 35.1%, and in DS hyperopia group 38.1%. Conclusions: The results of our study suggest that DS children and young adults with any refractive error do not have a higher chance of additional systemic manifestations. Myopia in DS was associated with a higher prevalence of nystagmus and iris stromal atrophy, whereas astigmatism was found to be more frequent in hyperopia.

Segmentation of the foveal and parafoveal retinal architecture using handheld spectral-domain optical coherence tomography in children with Down syndrome

BACKGROUND

Down syndrome is a common multigene, multisystem disorder associated with abnormalities of visual function and characteristic changes in the majority of tissues in the eye. Historic descriptions of macular structure in Down syndrome have been variable, but optical coherence tomography allows increasingly detailed characterization of retinal architecture in vivo. We demonstrate the feasibility of retinal imaging in children with Down syndrome using handheld OCT in an outpatient clinical setting, and describe the foveal and parafoveal retinal architecture in this group.

METHODS

Fourteen White British children aged between 4 and 11 with Down syndrome were recruited to have handheld SD-OCT retinal imaging performed at a single centre in an outpatient clinical setting. The thickness of the retinal layers at the fovea and parafovea was analysed using segmentation software, and compared with age-matched controls from a previously published normative UK dataset.

RESULTS

Sixty-seven percent of the children studied had grade 1 foveal hypoplasia. At the fovea, the ganglion cell layer (p = 0.002) and inner nuclear layer (p < 0.001) were thickened relative to the control group. At the parafovea, there was thickening of the retina attributable to numerous layers in both the inner and outer retina, which remained significant after Bonferroni correction.

CONCLUSION

OCT imaging of children with Down syndrome in an outpatient setting is feasible. There is a high incidence of foveal hypoplasia in this group, associated with thickening of the ganglion cell and inner nuclear layers at the fovea.

Prevalence of ophthalmological manifestations in pediatric and adolescent populations with Down syndrome: a systematic review of the literature

BACKGROUND

Down syndrome (DS) is a chromosomal anomaly that is characterized by an extra chromosome 21. Ophthalmological manifestations have a high prevalence in patients with DS.

PURPOSE

To review the scientific evidence and estimate the prevalence of ophthalmological manifestations in the pediatric population with DS.

DATA SOURCES

Electronic databases including MEDLINE, Cochrane Library, EMBASE, ScienceDirect, and LILACS.

STUDY ELIGIBILITY CRITERIA

Published observational studies with available and original data were included. Articles were excluded if the study design was a review, letter to the editor, case report, case series, or systematic review and if the subjects had ophthalmological manifestations secondary to other conditions.

PARTICIPANTS AND INTERVENTIONS

Pediatric and adolescent population with DS and with ophthalmological evaluation.

STUDY APPRAISAL AND SYNTHESIS METHODS

A data collection form was designed in Excel. Five reviewers extracted relevant details about the design and results of each study. The quality of the studies was assessed by applying the tools for systematic reviews of prevalence and incidence from the Joanna Briggs Institute. We calculated the weighted prevalence of ophthalmological manifestations, considering only the studies reporting the measurement of each manifestation.

RESULTS

Twenty-two articles (from 15 countries, published during 1994-2020) were included in the present systematic review. Ocular manifestations were observed in 85% of the studied pediatric and adolescent populations with DS. The most frequent ones were slanting fissures, oblique fissures, epicanthus, and epiblepharon.

CONCLUSION

The ocular manifestations in the pediatric and adolescent populations with DS are varied, and some can irreversibly affect visual development. Screening of the pediatric population with DS should be conducted from the first months of age and continued annually.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019127717.

Down syndrome: a review of ocular manifestations

Down syndrome is the most common genetically mediated intellectual disability. Although many physiologic and pathologic features of Down syndrome are discussed at length in the literature, the ocular manifestations of Down syndrome have seldom been discussed in a comprehensive fashion. Given that Down syndrome has ocular manifestations from the front to the back of the eye, it is important for physicians to become familiar with these manifestations, especially given the prevalence of Down syndrome. This review aims to discuss the varied ophthalmologic manifestations of Down syndrome – including strabismus, amblyopia, nystagmus, accommodation deficits, nasolacrimal duct obstruction, keratoconus, optic nerve pathology, neoplastic disease, and retinal pathology – to facilitate better care and visual outcomes in this important patient population.

Refractive and Vision Status in Down Syndrome: A Comparative Study

Objectives:

To determine the prevalence of refractive errors and visual impairment in Down syndrome (DS) patients compared to normal controls.

Materials and Methods:

Cycloplegic refraction was tested in 213 DS patients and 184 normal age- and gender-matched controls using autorefraction followed by retinoscopy. Data from the worse eye of each case were used in the analyses.

Results:

In the DS and control groups, respectively, mean age was 17.2±4.8 and 17.2±4.4 years (p=0.993) and 53.0% and 49.5% were male (p=0.473). In the DS and control groups, respectively, mean spherical equivalent (SE) was -5.13±4.47 and -4.15±3.04 diopters (D) in myopics (p=0.050) and 2.47±1.64 and 2.36±2.04 D in hyperopics (p=0.482), mean cylinder error was -2.17±1.39 and -2.05±1.57 D (p=0.451), mean J0 was -0.03±0.89 and 0.12±0.76 D (p=0.086), and mean J45 was 0.11±1.02 and -0.13±1.03 D (p=0.024). The prevalence of oblique astigmatism was higher in the DS group (20.4% vs. 6.1%) while against-the-rule astigmatism was more prevalent in the control group (84.0% vs. 71.6%) (p<0.001). The prevalence of anisometropia was not significantly different between the groups (19.4% vs. 13.8%). Visual impairment was detected in 11.7% of the DS and 0.5% of the control group (p<0.001). The prevalence of amblyopia was 36.3% and 3.8% in the DS and control groups, respectively (p<0.001). Based on the multiple model, only absolute SE inversely correlated with age and differed between males and females (all p<0.05).

Conclusion:

In DS patients, the prevalence rates of refractive errors, amblyopia, and visual impairment are higher than those in non-DS individuals, and emmetropization appears to be either defective or slow. Cylinder error is stable in this age range, but the rotation of astigmatism axis is different from normal samples.

Neuro-Ophthalmological Manifestations in Children with Down Syndrome: Current Perspectives

Down syndrome, caused by an extra copy of all or part of chromosome 21, is the most prevalent intellectual disability of genetic origin. Among numerous comorbidities which are part of the phenotype of individuals with Down syndrome, ocular problems appear to be highly prevalent. Neuro-ophthalmological manifestations, such as ocular alignment and motility disturbances, amblyopia, hypoaccommodation or optic nerve abnormalities, and other organic ocular anomalies frequently reported in Down syndrome, may lead to an overall decrease in visual acuity. Although numerous studies have reported ocular anomalies related to Down syndrome, it remains challenging to determine the impact of each anomaly upon the decreased visual acuity, as most such individuals have more than one ocular problem. Even in children with Down syndrome and no apparent ocular defect, visual acuity has been found to be reduced compared with typically developing children. Pediatric ophthalmological examination is a critical component of a multidisciplinary approach to prevent and treat ocular complications and improve the visual outcome in children with Down syndrome. This narrative review aims to provide a better understanding of the neuro-ophthalmological manifestations and discuss the current ophthalmological management in children with Down syndrome.

Challenges in Patients with Trisomy 21: A Review of Current Knowledge and Recommendations

Purpose

To summarize and review the common ophthalmic anomalies in children with trisomy 21 (Down syndrome) in order to propose an update to current clinical recommendations.

Methods

A retrospective chart review, systemic literature review, and international survey of the frequency of ocular abnormalities, screening schedules, and challenging aspects examining children with trisomy 21. The chart review included patients treated at the Department of Ophthalmology at the University Hospital of Zurich over a two-year period. The international survey was submitted to the members of the Swiss Society of Ophthalmology, Slovenian Ophthalmological Society, and European Pediatric Ophthalmology Society.

Results

Analysis of 52 patient records during the study period revealed refractive errors (astigmatism: 54% of patients, hyperopia: 26%, and myopia: 15%) as the most common diagnosis, whereas childhood cataract was reported in 5%. This is in concordance with the extended literature review of 249 publications, although congenital cataracts were reported to be higher than at our institution. The survey participants reported great challenges in taking care of these patients, despite their long professional experience (73% with over 10 years of experience).

Conclusion

Care and treatment of children with trisomy 21 continues to be demanding for paediatric ophthalmologists. We recommend the following examination schedule for these patients: first, ophthalmological examination at 6-12 months of age, then once in 3-6 months for children under 2 years of age, once in 6 months for children 2-5 years of age, annually for children 5-10 years of age, and thereafter, to be decided on an individual basis depending on the presenting ocular abnormalities of the patient.

Prevalence of keratoconus in persons with Down syndrome: a review

Purpose

Keratoconus is a vision-threatening condition, and there is a need for knowledge about the occurrence in subgroups of the population. The progression of the disease can be effectively stopped, and vision may be restored, if keratoconus is diagnosed at an early stage. The purpose of this review was to evaluate the literature of the prevalence of keratoconus in persons with Down syndrome.

Methods

We conducted a literature review of keratoconus prevalence in persons with Down syndrome. A thorough search was performed in Pubmed (Medline), and the quality of evidence was evaluated.

Results

The literature review identified 20 relevant studies, which reported keratoconus in 0%–71% of persons with Down syndrome. These studies varied greatly in design, patient selection, sample sizes and mean age, and the quality of evidence concerning estimates for the prevalence of keratoconus was generally evaluated as low. Most studies that included adults reported high prevalences of keratoconus–in many studies more than 10-fold the prevalence in the general population. No large screening studies in persons with Down syndrome were identified.

Conclusions

The present review showed that the prevalence of keratoconus in persons with Down syndrome is higher than in the general population. However, estimates from previous studies vary widely. Screening for keratoconus in this group should be considered.

Aqueous Misdirection After Trabeculectomy in a Down Syndrome Patient With Angle-closure Glaucoma

Down syndrome is a genetic disease caused by trisomy of chromosome 21 that is characterized by numerous systemic abnormalities including intellectual disability, stereotypical facies, and congenital heart malformations. Ocular abnormalities are commonly seen with Down syndrome including corneal disease (keratoconus), refractive error, and atypical irides (Brushfield spots). We report the first case of aqueous misdirection in a patient with Down syndrome after trabeculectomy. Patients with Down syndrome often have small, hyperopic eyes with narrow iridocorneal angles and may be at increased risk for aqueous misdirection associated with surgical procedures. Awareness of this risk may aid surgical planning and postoperative management.

Tomography-based definition of keratoconus for Down syndrome patients

Background

To assess the diagnostic ability of Pentacam HR (Oculus Optikgeräte, GmbH, Wetzlar, Germany) tomographic indices in discriminating keratoconus (KC) and KC suspect (KCS) in 10- to 30-year-old patients with Down syndrome (DS).

Methods

In this study, DS patients were enrolled through special needs schools, the National Down Syndrome Society, and relevant non-profit organizations. Diagnoses were made independently by two experienced specialists. Forty Pentacam indices related to corneal thickness, volume, density, keratometry, power, shape, aberration, and elevation were extracted. For each index, the accuracy for KC and KCS diagnosis was evaluated using discriminant analysis and the area under receiver operating characteristic curve (AUROC). From each enrolled case, data from only one eye was entered in the analyses.

Results

Analyses were performed on data from 25 KC, 46 KCS, and 154 non-ectatic DS eyes. The best discriminants for KC were anterior higher order aberrations (HOA) (cutoff > 0.643, AUROC = 0.879), posterior vertical coma (cutoff > 0.0702 μm, AUROC = 0.875), anterior vertical coma (cutoff > 0.4124 μm, AUROC = 0.868), and total HOA (cutoff > 0.608, AUROC = 0.867). The difference between AUROCs were not statistically significant (all P > 0.05). For KCS, the best discriminants were minimum corneal thickness (cutoff ≤ 480.0 μm, AUROC = 0.775), corneal volume (cutoff ≤ 55.3 μm, AUROC = 0.727) and Belin Ambrosio display-total deviation (BAD-D) (cutoff > 2.23, AUROC = 0.718) with no significant difference between AUROCs (all P > 0.05).

Conclusions

In this sample of DS patients, best KC discriminators were HOA and coma which showed good diagnostic ability. For KCS, best predictors were minimum corneal thickness, corneal volume, and BAD-D with relatively good diagnostic ability. Defining a new set of KC diagnostic criteria for DS patients is suggested.

Ophthalmological abnormalities in Down syndrome among Brazilian patients

Down syndrome is the most common chromosomal disorder, affecting 1/700 live births. Among the clinical findings, one constant concern is the high prevalence of visual disorders that, if left untreated, can negatively affect child development. The aim of this study was to determine the prevalence of ophthalmological findings among patients who attended an outpatient clinic for patients with Down syndrome in southern Brazil between 2005 and 2016. A cross-sectional study including 1,207 patients medical records were done, which 492 (40.8%) had some ophthalmological disorder. These data were subjected to descriptive analysis using Statistica software. Among the 492 patients with any ophthalmological disease, the need for glasses was found in 434 (36%) patients, keratoconus in 254 (42.1%), congenital cataract in 27 (15.1%), nasolacrimal duct obstruction in 25 (2.0%), strabismus in 22 (1.9%), nystagmus in four (0.3%), and juvenile cataract in two (0.2%). Two young adults with keratoconus underwent corneal transplantation. Although the prevalence of an ophthalmological disease among the present sample (40.8%) was lower than described in the current literature, it still reinforced the importance of routine and early evaluations in infants. These should begin at 6 months of age and be repeated half-year until 2 years old, annually until 7 years old, biennial in adolescents, and triennial in adults and elderly. Our findings of a high frequency of keratoconus support a detailed corneal study in such patients for early detection and treatment.

Illustration of tessellation in Down syndrome

Background: Tessellated fundus refers to a specific change in the appearance of the internal layers of the eye in which the choroidal large vessels became visible through polygonal hypopigmented areas. Such hypopigmented areas alternate with hyperpigmented zones in a tigroid pattern. Fundus tessellation is often associated with myopia and choroidal thinning.Materials and Methods: We analyzed fundus images from 50 children with Down syndrome and 52 controls.Results: Tessellation was present in 64% of children with Down syndrome, compared with only 13.5% of controls (p < .0001). In most cases, tessellation was located peripapillary, and no difference was observed in tessellation localization between children with Down syndrome and controls (p = .60). Although more prevalent in myopic children with and without Down syndrome, tessellation was present in almost half (48%) of children with Down syndrome with hyperopia versus only 5% of controls with the same refractive status.Conclusions: Mechanical stretching of the choroid could explain the high rate of tessellation in myopes. Other factors must contribute to the higher prevalence of tessellated fundus in children with Down syndrome without myopia. We discuss potentially relevant factors and propose vascular involvement as a contributor to tessellation in our population with Down syndrome. Further studies assessing choroidal vasculature in individuals with Down syndrome are needed to confirm this theory.

Keratoconus detection by novel indices in patients with Down syndrome: a cohort population-based study

PURPOSE

To use novel indices to determine the prevalence of KC and its progression in patients aged 10-30 years with Down syndrome.

STUDY DESIGN

Cohort population-based study.

METHODS

Two hundred twenty-six of 250 invited Down syndrome patients were enrolled. The diagnostic criteria were confirmed by two independent expert examiners using slit-lamp examinations and topographic indices measured by Pentacam HR (Oculus Optikgeräte): maximum keratometry centered on the steepest point (zonal Kmax-3 mm), Ambrósio's relational thickness (ART), inferior-superior asymmetry (IS-value), Belin/Ambrósio deviation value (BAD-D), the Tomographic and Biomechanical Index (TBI), and a posterior elevation map. In the KC cases, Corvis ST (Oculus Optikgeräte) was done. All the KC cases completed the second phase in 2017.

RESULTS

KC was identified in 28 patients (12.39%; 95% confidence interval: 8.2-17.9%): 20 bilateral and eight unilateral cases. Of these, 24 were in the ≤ 20-years age group, and four, in the > 20-years age group. The frequency of KC was not significantly correlated with age (P = 0.804) or gender (P = 0.322). In the KC cases, the mean zonal Kmax-3 mm, ART-max, IS-value, BAD-D, CBI, and TBI were 50.40 ± 5.88 D, 321.63 ± 111.94 μm, 1.99 ± 2.51, 3.73 ± 3.12, 0.54 ± 0.61, and 0.86 ± 0.20, respectively, and the minimum corneal thickness was 492.17 ± 42.67 μm. Of the 28 patients, 39.6% showed progression, and all were in the ≤ 20-years age group.

CONCLUSION

The prevalence of KC in Down syndrome patients is significantly higher than that reported in non-Down syndrome individuals of the same age groups. The progression rate is approximately similar to that of the non-Down syndrome population. Screening programs should be applied to prohibit serious visual impairment in these populations.

Ocular alignment, media, and eyelid disorders in Down syndrome

Background: Determining the age and gender distribution of ocular disorders in Down syndrome patients aged 10 to 30 years.Methods: In this study, 226 of 250 invited patients through special needs schools, the National Down Syndrome Society, and relevant nonprofit organizations were included. In Noor Eye Hospital, the patients underwent a complete eye examination by a general ophthalmologist and suspect cases were reexamined by a sub-specialist. Examinations included ocular alignment, conjunctiva, eyelid, lacrimal system, cornea, iris, and lens assessment.Results: Mean age of participants was 16.05 ± 4.82 years and 53.0% were male. The most common ocular abnormalities were blepharitis (81.9%, 95% CI:78.0 to 85.3), lens opacity (37.8%, 95% CI:33.3 to 42.3), strabismus (23.4%, 95% CI:19.5 to 27.4; 21.2% esotropia, 0.9% exotropia, and 1.8% dissociated vertical deviation), floppy eyelid (19.9%, 95% CI:16.3 to 23.9), posterior embryotoxon (17.7%, 95% CI:14.2 to 21.2) and nystagmus (11.7%, 95% CI:8.9 to 15.0). Based on independent sample t test, the prevalence of nystagmus (P = .041) and congenital lens opacity  (P<0.001) significantly increased with age. There was no significant inter-gender difference in the prevalence of any of the studied disorders by chi-square test.Conclusion: In young patients with Down syndrome, the prevalence of ocular pathologies appears to be high and increase with aging. It can be resulted from the cumulative prevalence of undiagnosed or untreated cases. Findings of the study can be a reliable reference for health policy in terms of screening for eye disease and addressing eye care needs.

Prevalence of Ocular Pathology on Initial Screening and Incidence of New Findings on Follow-up Examinations in Children With Trisomy 21

PURPOSE

Various ophthalmologic findings have been associated with trisomy 21. However, prior studies on this topic are limited by their sample size and the lack of follow-up regarding the incidence of new pathology after an initially normal examination. We determined whether children who have a normal first examination need to have formal reevaluation by an ophthalmologist.

DESIGN

Retrospective cohort study.

METHODS

Records were reviewed for 689 patients with trisomy 21 evaluated at Vanderbilt Eye Institute between 2012 and 2017. Ocular and refractive abnormalities present on initial screening were recorded and follow-up data were reviewed to determine if new abnormalities developed at subsequent visits.

RESULTS

Of the 689 patients, 410 (59.5%) had a significant finding on their first examination. The most common abnormalities seen on initial screening examination were strabismus, significant refractive error, and eyelid abnormalities (including ectropion and accessory puncta). Of the 279 initially normal patients, 179 had at least 1 follow-up visit at a mean follow-up interval of 21.6 months (average age 3.7 years). At the first follow-up visit, 129 remained normal, while 50 had a new abnormality, most commonly significant refractive error and strabismus. On second follow-up visit, at a mean follow-up interval of 12 months (average age 4.8 years), 63% remained normal.

CONCLUSIONS

Ocular pathology occurs in trisomy 21 at a much higher prevalence than the general population; thus these children initially should have a comprehensive eye examination. Although the development of new ocular pathology in a child with trisomy 21 and a previously normal examination is not unusual, most of these new abnormalities are detectable with automated vision screening techniques or direct visual inspection of the eyes and ocular adnexa; thus once a child has a normal examination, a formal vision screening could replace a formal ophthalmologic examination.

Abnormalities of the Optic Nerve in Down Syndrome and Associations With Visual Acuity

Background: Various ocular anomalies are present in the vast majority of individuals with Down syndrome; however, we know little about optic nerve abnormalities. The aim of this cross-sectional comparative study was to describe optic disc morphology in patients with Down syndrome and to determine if the differences found are potentially related to visual acuity.

Subjects/methods: Assessable fundus images were obtained in 50 children with Down syndrome and 52 children without Down syndrome. Morphological analysis of the optic nerve was performed, including the disc-to-macula distance (DM) to disc diameter (DD) ratio (DM/DD), the cup-to-disc ratio and optic disc ovality. Data relating to ophthalmological status were retrospectively analyzed to evaluate the possible causes of reduced visual acuity.

Results: DM/DD was significantly larger (p = 0.0036) and the cup-to-disc ratio was significantly smaller (p = 0.018) in children with Down syndrome, compared to controls. The optic discs were also more frequently torted (p = 0.034), tilted (p = 0.0049) and oval (p = 0.026). Furthermore, crescents (p = 0.0002), peripapillary atrophy (p = 0.0009), and pigment anomalies (p < 0.0001) were also more prevalent in children with Down syndrome than in those without. Visual acuity was significantly lower in children with Down syndrome compared to controls with similar refraction problems and strabismus prevalence (p < 0.0001). The mean DM/DD and the presence of a crescent was not directly related to visual acuity (r = 0.39, p = 0.31), (r = 0.35, p = 0.12) respectively. Visual acuity was diminished in 80% of children with Down syndrome and the smallest discs and in 84% of those with tilted discs. However, other causes may contribute to the diminished visual acuity in these cases.

Conclusion: The optic nerve head in children with Down syndrome is affected by various anatomical and developmental abnormalities. Unrelated to refraction (spherical equivalent), the optic discs appear smaller and more frequently mal-inserted in Down syndrome. Optic disc hypoplasia, as well as severe tilting, may reduce vision but they do not represent major contributors to the decrease of vision in such children. As these children often have multiple ocular and neurosensory problems, it remains challenging to relate visual acuity problems with a specific abnormality. Smaller discs may lead to optic disc drusen formation in children with Down syndrome.

Visual assessment in Down Syndrome: The relevance of early visual functions

BACKGROUND

Children with Down Syndrome (DS) have a high prevalence of ocular disorders, and even when ophthalmological deficits (i.e. refractive errors or strabismus) are corrected, visual acuity seems to have a different developmental trend compared to typical children. Unfortunately, there is no consensus about the age at which it is fundamental to perform a first comprehensive visual assessment in this population.

AIMS

We analyzed early visual functions in a sample of 42 Italian children with DS, in order to achieve new insights for early surveillance and intervention.

MATERIAL AND METHODS

DS children were evaluated with the Early Neurovisual Assessment, including Teller Acuity Cards (at 6, 12 and 18 months of age) and the Pediatric Ophthalmological Examination (within the 36th months of age).

RESULTS

Visual acuity in our sample was lower than findings reported in the literature on healthy Italian children, but the values were within the confidence interval reported in previous studies on DS children. Moderate or severe refractive errors (> 3diopters) were present in five children (four had hyperopia and one myopia). Abnormalities in ocular motility were observed in 15 children and pathological findings for fundus oculi or lens were found in another eight. Furthermore, ophthalmological findings correlated with visual acuity at 18 months of age.

CONCLUSION

According to our results, the Early Neurovisual Assessment at 18 months of life is a reliable tool for early detection of visual disorders in children with DS and it is useful for programming early intervention to promote their neurodevelopment.

Brushfield spots and Wölfflin nodules unveiled in dark irides using near-infrared light

Wölfflin nodules and Brushfield spots were described essentially in light colored irides. The purpose of our study is to determine if these iris features are also present in dark irides, hidden by melanin granules of the anterior leaf of the iris. We examined iris images, taken with standard visible white, as well as with near-infrared light of children with Down syndrome and without. Using white light, Brushfield spots were seen in 21% of children with Down syndrome, and Wölfflin nodules in 12% of controls (p < 0.001), all noted in those with lightly colored irides. Brushfield spots were detected in 67% of children with Down syndrome using near-infrared light compared to 21% using white light (p < 0.001). Wölfflin nodules were detected in 19% of controls using near-infrared light compared to 12% using white light. Peripheral iris thinning was present in 63% of children with Down syndrome but in only 23% of those without (p = 0.001). Contraction furrows were less frequent in children with Down syndrome (16%) compared to controls (74%)(p < 0.001). Near-infrared light unveils Brushfield spots and Wölfflin nodules in dark irides. Clearing this discrepancy should assist in the elucidation of their pathophysiologic origin. A high prevalence of peripheral iris thinning is also present in children with Down syndrome along with a heretofore unreported reduction in iris contraction furrows.

Ocular findings in Japanese children with Down syndrome: the course of visual acuity and refraction, and systemic and ocular anomalies

PURPOSE

To investigate the age-related development of refractive errors and changes of visual acuity (VA), and the systemic and ocular anomalies in Japanese children and young adults with Down syndrome (DS).

DESIGN

Retrospective cohort study.

SUBJECTS AND METHODS

This study involved 222 Japanese children and young adults with DS (age range: 3 months to 19 years) seen at the Department of Ophthalmology, Shiga Medical Center for Children, Shiga, Japan. The subjects were divided into the following six age groups: 1) infant (age 0 to <4 years), 2) preschool (age 4 to <7 years), 3) lower primary-school grades (age 7 to <10 years), 4) upper primary-school grades (age 10 to <13 years), 5) junior high school (age 13 to <16 years), and 6) late teen/young adults (age 16 to <20 years). Through examination of the subjects' medical charts, we investigated the development and changes of refractive errors and VA, best-corrected VA (BCVA), and systemic and ocular anomalies.

RESULTS

For vision testing, Teller Acuity Cards™ (Bernell Corporation) were used for the infants, and the Landolt ring was used for the school-age children. VA was found to develop with age. Mean BCVA was 0.19±0.17 logarithm of the minimum angle of resolution (mean age: 11.3±3.2 years). Mean of refractive errors was hyperopia in the infant (2.2±2.4 diopters [D] OD, 2.4±2.5D OS), yet became myopia to the junior high school (-0.3±4.4D OD, -0.2±4.4D OS).

CONCLUSION

Our findings revealed that in children and in late-teen and young-adult subjects with DS, VA slowly develops and that refractive errors requiring correction exist and are difficult to examine.

Syndromic and Nonsyndromic Systemic Associations of Congenital Lacrimal Drainage Anomalies: A Major Review

PURPOSE

To review and summarize the syndromic, nonsyndromic, and systemic associations of congenital lacrimal drainage anomalies.

METHODS

The authors performed a PubMed search of all articles published in English on congenital lacrimal anomalies (1933-2016). Patients of these articles were reviewed along with the literature of direct references to syndromes and other systemic associations. Data reviewed included syndromic descriptions, systemic details, demographics, lacrimal presentations, management, and outcomes.

RESULTS

Syndromic and systemic associations with congenital lacrimal drainage disorders are not known to be common. Although familial presentations have been reported, the inheritance patterns are unclear for most anomalies. There is an increasingly growing evidence of a genetic basis to many lacrimal anomalies. However, few syndromes have either widespread or are frequently associated with lacrimal anomalies. Few sequences of distinct lacrimal presentations and intraoperative findings are seen. Surgical challenges in these patients are distinct and a thorough pre and intraoperative anatomical assessment, detailed imaging when indicated, and assessment and correction of associated periocular and facial abnormalities may facilitate good outcomes.

CONCLUSIONS

Lacrimal drainage anomalies associated with syndromic and nonsyndromic systemic conditions have certain unique features of their own and their surgical and anesthesia challenges are distinct. Diagnosis of congenital lacrimal drainage anomalies should prompt consideration of the possible presence of associated systemic abnormalities.

Visual characteristics of children with Down syndrome

PURPOSE

To analyze long-term visual development in children with Down syndrome who received early ophthalmological intervention.

METHODS

A total of 125 children with Down syndrome who were examined before 6 years of age and followed up for more than 5 years were selected. Visual development, refraction, visual acuity testing, and the prescription of spectacles were examined retrospectively.

RESULTS

Mean visual acuity by age was as follows: 2 years, 1.13 ± 0.23 logarithm of the minimum angle of resolution (logMAR); 5 years, 0.55 ± 0.25 logMAR; 8 years, 0.27 ± 0.19 logMAR; 11 years, 0.17 ± 0.16 logMAR; and 14 years, 0.10 ± 0.15 logMAR. In 32 children (25.6%), visual acuity reached 0.0 logMAR or better. Hyperopia of +2D or more was observed in 132 eyes (52.8%), and astigmatism of 2D or more was observed in 153 eyes (61.2%). Subjective testing was difficult in many children prior to 4.5 years of age, and grating acuity testing was necessary. Spectacles were prescribed at a mean age of 3.5 ± 1.6 years in 120 children (96.0%). The average duration until the spectacles were worn constantly was 9.0 ± 9.3 months.

CONCLUSION

Early ophthalmological intervention and longitudinal care is important for children with Down syndrome.

Molecular and Histopathological Changes Associated with Keratoconus

Keratoconus (KC) is a corneal thinning disorder that leads to loss of visual acuity through ectasia, opacity, and irregular astigmatism. It is one of the leading indicators for corneal transplantation in the Western countries. KC usually starts at puberty and progresses until the third or fourth decade; however its progression differs among patients. In the keratoconic cornea, all layers except the endothelium have been shown to have histopathological structural changes. Despite numerous studies in the last several decades, the mechanisms of KC development and progression remain unclear. Both genetic and environmental factors may contribute to the pathogenesis of KC. Many previous articles have reviewed the genetic aspects of KC, but in this review we summarize the histopathological features of different layers of cornea and discuss the differentially expressed proteins in the KC-affected cornea. This summary will help emphasize the major molecular defects in KC and identify additional research areas related to KC, potentially opening up possibilities for novel methods of KC prevention and therapeutic intervention.

Simulated Keratometry Repeatability in Subjects with and without Down Syndrome

PURPOSE

To assess the repeatability of simulated keratometry measures obtained with Zeiss Atlas topography for subjects with and without Down syndrome (DS).

METHODS

Corneal topography was attempted on 140 subjects with DS and 138 controls (aged 7-59 years). Subjects who had at least three measures in each eye were included in analysis (DS: n = 140 eyes (70 subjects) and controls: n = 264 eyes (132 subjects)). For each measurement, the steep corneal power (K), corneal astigmatism, flat K orientation, power vector representation of astigmatism (J0, J45), and astigmatic dioptric difference were determined for each measurement (collectively termed keratometry values here). For flat K orientation comparisons, only eyes with >0.50 DC of astigmatism were included (DS: n = 131 eyes (68 subjects) and control: n = 217 eyes (119 subjects)). Repeatability was assessed using (1) group mean variability (average standard deviation (SD) across subjects), (2) coefficient of repeatability (COR), (3) coefficient of variation (COV), and (4) intraclass correlation coefficient (ICC).

RESULTS

The keratometry values showed good repeatability as evidenced by low group mean variability for DS versus control eyes (≤0.26D vs. ≤0.09D for all dioptric values; 4.51° vs. 3.16° for flat K orientation); however, the group mean variability was significantly higher in DS eyes than control eyes for all parameters (p ≤ 0.03). On average, group mean variability was 2.5 times greater in the DS eyes compared to control eyes across the keratometry values. Other metrics of repeatability also indicated good repeatability for both populations for each keratometry value, although repeatability was always better in the control eyes.

CONCLUSIONS

DS eyes showed more variability (on average: 2.5×) compared to controls for all keratometry values. Although differences were statistically significant, on average 91% of DS eyes had variability ≤0.50D for steep K and astigmatism, and 75% of DS eyes had variability ≤5 degrees for flat K orientation.

Ophthalmic manifestations in children and young adults with Down syndrome and congenital heart defects

PURPOSE

To investigate whether different types of ocular manifestations are associated with congenital heart disease (CHD) in a large Caucasian population of children and young adults with Down syndrome (DS).

METHODS

Population-based, case-control study which included 185 subjects with DS (mean age 13.2 ± 7.9 years), who reported presence or absence of CHD; DS with CHD group (51 subjects, mean age 10.6 ± 5.6 years) and DS without CHD (134 subjects, mean age 14.2 ± 8.4 years).

RESULTS

In our sample with DS and CHD, strabismus was found in 15 subjects (29.4%), nystagmus in 1 (2.0%), epiblepharon in 21 (41.2%) and Brushfield spots in 15 (31.3%). In the DS without CHD group, strabismus was found in 38 participants (28.4%), nystagmus in 13 (9.7%), epiblepharon in 31 (23.5%) and Brushfield spots in 21 (16.0%). Only the variables epiblepharon and presence of Brushfield spots differed significantly between the two groups (p = 0.02 and p = 0.03, respectively). Hyperopia was present in 26 participants (53.1%) in the DS with CHD group, and in 65 (57.0%) in the DS without CHD group. Oblique astigmatism was present in 25 (52.1%) in the DS with CHD group and in 61 (53.5%) in the DS without CHD group.

CONCLUSIONS

Frequencies of DS participants presenting with strabismus, nystagmus, hyperopia and oblique astigmatism were not statistically different between those with CHD and those without CHD in this sample. Further studies are needed to confirm if there are associations between the presence of Brushfield spots or epiblepharon and CHD in patients with DS.

Macular structural characteristics in children with Down syndrome

PURPOSE

This prospective study aimed to investigate macular structural characteristics in children with Down syndrome compared to those in healthy children.

METHODS

Two groups of children (aged 6-16 years) were enrolled: children with Down syndrome (Down syndrome group, N = 17) and age-matched healthy children who were full-term at birth (control group, N = 18). Eligible patients had visual acuity of 20/100 or better and gestational age at birth of ≥ 36 weeks. Fourier domain optical coherence tomography was used for imaging of the macular retinal structure, and retinal volume scans centered on the macula were obtained. Central subfield thickness (CST) and the thickness of the inner and outer retinal layer regions were analyzed using the instrument's segmentation software. The analysis of data is provided for the right eye only, since there was no significant difference between right and left eyes for either the Down syndrome or control groups.

RESULTS

Children in the Down syndrome group generally had identifiable retinal structure. The CST for the full retina and inner and outer retinal layers were all significantly greater in the Down syndrome group than the control group (independent t test, all p < 0.05). Despite the significantly thicker macula, only about 29 % (5 of 17) of the right eyes of patients with Down syndrome had macular thickness outside the normal range. Visual acuity in the Down syndrome group was not directly correlated with increased CST (t = 1.288, r = 0.326, p = 0.202).

CONCLUSIONS

On average, CST in the Down syndrome group was greater than that in the control group, suggesting abnormal macular development in children with Down syndrome.

Differences of the anterior segment parameters in children with down syndrome

PURPOSE

The study was undertaken to investigate whether anterior segment findings are different in children with Down syndrome (DS) to normal children and to focus on its clinical significance.

METHODS

A cross-sectional case control study was conducted in a total of 38 children with DS and 42 healthy children. This is the first report in the literature stating that. All subjects underwent ophthalmologic examination including slit-lamp biomicroscopy, cycloplegic refraction, intraocular pressure measurement and Scheimpflug imaging measurement. Customized software for Pentacam was used to analyze structural indices of anterior segment parameters. The mean anterior segment values of right eyes were compared between the groups.

RESULTS

The mean anterior chamber parameters of patients with DS and controls were measured respectively: Corneal thickness was 502.31 ± 40.5 and 541.8 ± 37.42 mm (p < 0.001), corneal volume was 56.63 ± 4.5 and 61.02 ± 4.3 mm³ (p < 0.001), corneal radius curvature was 7.41 ± 0.29 and 7.67 ± 0.34 mm (p < 0.001), iridocorneal angle was 39.7 ± 6.2 and 39.5 ± 6.4° (p = 0.944), anterior chamber volume was 181.65 ± 27.38 and 185.77 ± 32.53 m³ (p = 0.528), anterior chamber depth was 3.08 ± 0.24 and 3.02 ± 0.31 mm (p = 447), pupil size was 2.95 ± 0.48 and 3.29 ± 0.45 mm (p < 0.05).

CONCLUSION

The majority of the anterior segment parameters were found to be different in children with Down syndrome. While pupil size, corneal thickness, corneal volume and corneal curvature in DS were less than normal, iridocorneal angle, anterior chamber depth and anterior chamber volume were close to controls. The most important parametric differences in children with DS were seen on the cornea.

Intraoperative OCT of bilateral macular coloboma in a child with Down syndrome

A 3-year-old girl with Down syndrome presented with a macular lesion in both eyes. With intraoperative optical coherence tomography confirmation, the patient was diagnosed as having bilateral macular coloboma. These findings were previously reported in two patients with Down syndrome. The documentation of similar findings in three separate patients suggests that macular coloboma may be a rare ophthalmic pathology associated with Down syndrome. Moreover, optical coherence tomography imaging may be a useful adjunct in diagnosing macular coloboma in the pediatric population.

Strabismus, refractive errors and nystagmus in children and young adults with Down syndrome

PURPOSE

The aims of the present population-based, cross-sectional study were to examine the frequency and type of strabismus, refractive errors and nystagmus in children and young adults with Down syndrome (DS) in Macedonia and Croatia.

METHODS

A total of 170 unselected children and young adults with DS aged 1-34 years were examined for ocular findings. The ocular examination included: a visual acuity assessment, cycloplegic refraction, ocular alignment and ocular motility.

RESULTS

Strabismus was found in 45 of 170 children (26.5%), and esodeviation was the most common type. Nine (20%) had exodeviation and 4 (8.9%) vertical deviation. In 27 of 32 esotropic patients, the strabismus was regarded as acquired esodeviations. The frequency of strabismus was lowest in the high-grade hyperopia group (5%). Concerning esodeviations, fewer cases (3%) were in the high-grade hyperopia group. Most of the cases with esodeviations were in correlation with low-grade hyperopia (31%), myopia (28 %) and emetropia (16%). Hyperopia was the most common refractive error and high myopia increased in prevalence in the over 20 age group. Astigmatism was present in 72.4% of patients. Nystagmus was observed in 18 patients. Ten of 18 patients with nystagmus were associated with the presence of strabismus (9 esodeviations, 1 exotropia).

CONCLUSION

In our study, the high prevalence of strabismus can not be attributed to the presence of hyperopia. Our data show no association between refraction and strabismus in children with DS. Oblique astigmatism has been found to be the most common type of astigmatism in our study group.

Paediatric powered endonasal dacryocystorhinostomy

Dacryocystorhinostomy (DCR) is indicated in children with persistent nasolacrimal duct obstruction (NLDO). Endoscopic endonasal DCR has been successfully performed in both adults and children, with success rates similar to that of external DCR. This paper aims to evaluate the outcomes of paediatric patients undergoing endonasal endoscopic DCR at a district general hospital. A retrospective review of all patients attending a joint lacrimal clinic undergoing endonasal endoscopic DCR between October 2001 and December 2008 was performed. Sixteen children (17 eyes) aged between 2 and 14 were analysed. The main outcome measure was resolution of symptoms. Fourteen cases (82%) presented with epiphora with or without stickiness. Three cases had recurrent dacryocystitis. Three patients had Down syndrome. There were no operative complications. During a mean post-operative period of 12 months, all but one case showed an improvement of symptoms. While 60% of the patients had a complete resolution of symptoms, the remaining were minimally symptomatic. Of those with residual symptoms, two had Down syndrome. Endonasal DCR is a safe and effective intervention for children with persistent NLDO. Success is higher in children with no craniofacial abnormality. Joint care under a consultant Oculoplastic and ENT surgeon provides optimum care for these patients.

Screening athletes with Down syndrome for ocular disease

BACKGROUND

Persons with Down syndrome are well known to have a high prevalence of vision and eye health problems, many of which are undetected or untreated primarily because of infrequent ocular examinations. Public screening programs, directed toward the pediatric population, have become more popular and commonly use letter or symbol charts. This study compares 2 vision screening methods, the Lea Symbol chart and a newly developed interactive computer program, the Vimetrics Central Vision Analyzer (CVA), in their ability to identify ocular disease in the Down syndrome population.

METHODS

Athletes with Down syndrome participating in the European Special Olympics underwent an ocular screening including history, auto-refraction, colour vision assessment, stereopsis assessment, motility assessment, pupil reactivity, and tonometry testing, as well as anterior segment and fundus examinations to evaluate for ocular disease. Visual acuity was tested with the Lea chart and CVA to evaluate these as screening tests for detecting ocular disease as well as significant, uncorrected refractive errors.

RESULTS

Among the 91 athletes that presented to the screening, 79 (158 eyes) were sufficiently cooperative for the examination to be completed. Mean age was 26 years +/-10.8 SD. Significant, uncorrected refractive errors (>/=1.00 spherical equivalent) were detected in 28 (18%) eyes and ocular pathology in 51 (32%) eyes. The Lea chart sensitivity and specificity were 43% and 74%, respectively, for detecting ocular pathology and 58% and 100% for detecting uncorrected refractive errors. The CVA sensitivity and specificity were 70% and 86% for detecting pathology and 71% and 100% for detecting uncorrected refractive errors.

CONCLUSION

This study confirmed the findings of prior studies in identifying a significant presence of uncorrected refractive errors and ocular pathology in the Down syndrome population. Screening with the Lea symbol chart found borderline sufficient sensitivity and specificity for the test to be used for screening in this population. The better sensitivity and specificity of the CVA, if adjusted normative values are utilized, appear to make this test sufficient for testing Down syndrome children for identifying both refractive errors and ocular pathology.

[Frequency and clinical presentation of congenital ocular anomalies in Asturias 1990-2004]

INTRODUCTION

Congenital ocular anomalies (COAs) can produce serious disability.

OBJECTIVE

The purpose of this investigation was to assess the prevalence of COAs, their trends and to describe the associated malformations and syndromes in a geographically defined population.

METHOD

Data from the Asturias Registry of Congenital Defects were used. The period studied was from 1990 to 2004 and the study population the 103,452 births of mothers living in the region. Total prevalence was calculated.

RESULTS

A total of 3035 cases with congenital defects were recorded, of these 70 had COAs. The total prevalence was 6.8 per 10000 births, with a stable trend during this period. The most common COAs were: congenital cataract (2.0 per 10000 births), anophthalmos/microphthalmos (1.4 per 10000 births) and coloboma (1.3 per 10000 births). 40% of COAs occurred as isolated defects, 37% were syndromes and 23% were associated with other congenital defects.

CONCLUSIONS

The prevalence of COAs in Asturias over this period had a stable trend and the congenital cataract was the commonest COAs. COAs, particularly the anophthalmos/microphthalmos were associated with other congenital anomalies.

Microbial keratitis in patients with down syndrome: a retrospective study

PURPOSE

To study the microbiological and clinical profile of cases of microbial keratitis in patients with Down syndrome.

METHODS

A retrospective chart review of all patients with Down syndrome and microbial keratitis admitted to the Royal Victorian Eye and Ear Hospital, Melbourne, Australia, between January 1997 and January 2007 was undertaken. Main parameters evaluated were clinical and microbiological profile and final outcome.

RESULTS

Of 18 patients included in this study, 11 were men and 7 were women, with mean age of 50 +/- 29 years (range 20-61 years). The most common associated ocular abnormality was eyelid diseases (94%) followed by atopic keratoconjunctivitis (44%). Positive microbiological cultures were obtained in 5 (28%) cases with Streptococcus pneumoniae being the most prevalent isolate. Ocular herpes was detected in 2 patients with polymerase chain reaction. Surgical intervention was required in 13 (72%) patients in the form of keratoplasty (n = 3) corneal gluing (n = 2), tarsorrhaphy (n = 5), botox injection (n = 1), and enucleation (n = 2).

CONCLUSIONS

Microbial keratitis in Down syndrome is associated with eyelid problems and ocular atopy, and due to failure of medical therapy alone, surgical intervention is required in majority of cases.