Ocular colobomata

Ocular manifestations of renal ciliopathies

Renal ciliopathies are a common cause of kidney failure in children and adults, and this study reviewed their ocular associations. Genes affected in renal ciliopathies were identified from the Genomics England Panels. Ocular associations were identified from Medline and OMIM, and the genes additionally examined for expression in the human retina ( https://www.proteinatlas.org/humanproteome/tissue ) and for an ocular phenotype in mouse models ( http://www.informatics.jax.org/ ). Eighty-two of the 86 pediatric-onset renal ciliopathies (95%) have an ocular phenotype, including inherited retinal degeneration, oculomotor disorders, and coloboma. Diseases associated with pathogenic variants in ANK6, MAPKBP1, NEK8, and TCTN1 have no reported ocular manifestations, as well as low retinal expression and no ocular features in mouse models. Ocular abnormalities are not associated with the most common adult-onset "cystic" kidney diseases, namely, autosomal dominant (AD) polycystic kidney disease and the AD tubulointerstitial kidney diseases (ADTKD). However, other kidney syndromes with cysts have ocular features including papillorenal syndrome (optic disc dysplasia), Hereditary Angiopathy Nephropathy, Aneurysms and muscle Cramps (HANAC) (tortuous retinal vessels), tuberous sclerosis (retinal hamartomas), von Hippel-Lindau syndrome (retinal hemangiomas), and Alport syndrome (lenticonus, fleck retinopathy). Ocular abnormalities are associated with many pediatric-onset renal ciliopathies but are uncommon in adult-onset cystic kidney disease. However the demonstration of ocular manifestations may be helpful diagnostically and the features may require monitoring or treatment.

Ocular manifestations of congenital anomalies of the kidney and urinary tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) are among the most common birth defects worldwide and a major cause of kidney failure in children. Extra-renal manifestations are also common. This study reviewed diseases associated with the Genomics England CAKUT-associated gene panel for ocular anomalies. In addition, each gene was examined for expression in the human retina and an ocular phenotype in mouse models using the Human Protein Atlas and Mouse Genome Informatics databases, respectively. Thirty-four (54%) of the 63 CAKUT-associated genes (55 'green' and 8 'amber') had a reported ocular phenotype. Five of the 6 most common CAKUT-associated genes (PAX2, EYA1, SALL1, GATA3, PBX1) that represent 30% of all diagnoses had ocular features. The ocular abnormalities found with most CAKUT-associated genes and with five of the six commonest were coloboma, microphthalmia, optic disc anomalies, refraction errors (astigmatism, myopia, and hypermetropia), and cataract. Seven of the CAKUT-associated genes studied (11%) had no reported ocular features but were expressed in the human retina or had an ocular phenotype in a mouse model, which suggested further possibly-unrecognised abnormalities. About one third of CAKUT-associated genes (18, 29%) had no ocular associations and were not expressed in the retina, and the corresponding mouse models had no ocular phenotype. Ocular abnormalities in individuals with CAKUT suggest a genetic basis for the disease and sometimes indicate the affected gene. Individuals with CAKUT often have ocular abnormalities and may require an ophthalmic review, monitoring, and treatment to preserve vision.

A case report of retinal dystrophy in patients with PACS1 syndrome

PACS1 syndrome, also referred to as Schuurs-Hoeijmakers syndrome, is a multisystemic developmental disorder caused by a specific pathogenic variant in the PACS1 (phosphofurin acidic cluster sorting protein 1) gene. Ocular findings in PACS1 syndrome are known to include iris, retina, optic nerve coloboma, myopia, nystagmus, and strabismus. Here, we present the cases of two patients referred to the University of Wisconsin-Madison Department of Ophthalmology and Visual Sciences for ocular evaluation. The first patient is a 14-month-old female who, at 3 months of age, was found to have a depressed rod and cone response on electroretinogram (ERG), consistent with possible retinal dystrophy (RD). This feature has not been previously described in PACS1 syndrome and joins a growing list of calls for expanding the PACS1 phenotype. The second case illustrates a 5-year-old male referred for ocular screening after diagnosing PACS1 syndrome and underwent ERG without abnormal findings. These cases demonstrate the significant variability in the ophthalmic presentation of PACS1 syndrome and the need for early screening. These novel findings may have implications in understanding the mechanism of the PACS1 protein and its role in retinal ciliary phototransduction in photoreceptors.

Double temporal retinochoroidal coloboma with posterior embyotoxon and persistent pupillary membrane: a case report

Ocular colobomas are typically located in the inferonasal quadrant and attributable to defective fetal fissure closure. Colobomas can, however, affect any part of the eye, from the eyelid to the optic nerve. We present the case of a 7-year-old girl with two retinochoroidal colobomas in an atypical temporal location, with associated other ocular defects.

Secondary glaucoma: Toward interventions based on molecular underpinnings

Glaucoma is a heterogeneous group of progressive diseases that leads to irreversible blindness. Secondary glaucoma refers to glaucoma caused by a known underlying condition. Pseudoexfoliation and pigment dispersion syndromes are common causes of secondary glaucoma. Their respective deposits may obstruct the trabecular meshwork, leading to aqueous humor outflow resistance, ocular hypertension, and optic neuropathy. There are no disease-specific interventions available for either. Pseudoexfoliation syndrome is characterized by fibrillar deposits (pseudoexfoliative material) on anterior segment structures. Over a decade of multiomics analyses taken together with the current knowledge on pseudoexfoliative glaucoma warrant a re-think of mechanistic possibilities. We propose that the presence of nucleation centers (e.g., vitamin D binding protein), crosslinking enzymes (e.g., transglutaminase 2), aberrant extracellular matrix, flawed endocytosis, and abnormal aqueous-blood barrier contribute to the formation of proteolytically resistant pseudoexfoliative material. Pigment dispersion syndrome is characterized by abnormal iridolenticular contact that disrupts iris pigment epithelium and liberates melanin granules. Iris melanogenesis is aberrant in this condition. Cytotoxic melanogenesis intermediates leak out of melanosomes and cause iris melanocyte and pigment epithelium cell death. Targeting melanogenesis can likely decrease the risk of pigmentary glaucoma. Skin and melanoma research provides insights into potential therapeutics. We propose that specific prostanoid agonists and fenofibrates may reduce melanogenesis by inhibiting cholesterol internalization and de novo synthesis. Additionally, melatonin is a potent melanogenesis suppressor, antioxidant, and hypotensive agent, rendering it a valuable agent for pigmentary glaucoma. In pseudoexfoliative glaucoma, where environmental insults drive pseudoexfoliative material formation, melatonin's antioxidant and hypotensive properties may offer adjunct therapeutic benefits. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.

Congenital anomalies of lens shape

The crystalline lens is an important structure in the eye that starts to develop as early as the 22nd day of gestation, with further differentiation that continues after the induction. Congenital anomalies of the lens may involve the size, shape, and position of the lens. They may sometimes be associated with anterior segment dysgenesis or persistence of the tunica vasculosa lentis and hyperplastic vitreous and hyaloid system. Manifestations of anomalies of the lens shape are usually seen in early or late childhood however may sometimes be delayed into adulthood based on the level of visual impairment or the presence or absence of any syndromic associations. While lens coloboma has more often been reported in isolation, the more commonly implicated genes include the PAX6 gene, lenticonus in particular anterior is often part of Alport syndrome with extra-ocular manifestations in the kidneys and hearing abnormalities due to mutations in the alpha 5 chain of the Type IV collagen gene. Recognition of these manifestations and obtaining a genetic diagnosis is an important step in the management. The level of visual impairment and amblyopia dictates the outcomes in patients managed either conservatively with optical correction as well as surgically where deemed necessary. This review discusses the various anomalies of the lens shape with its related genetics and the management involved in these conditions.

Eye Morphogenesis in Vertebrates

Proper eye structure is essential for visual function: Multiple essential eye tissues must take shape and assemble into a precise three-dimensional configuration. Accordingly, alterations to eye structure can lead to pathological conditions of visual impairment. Changes in eye shape can also be adaptive over evolutionary time. Eye structure is first established during development with the formation of the optic cup, which contains the neural retina, retinal pigment epithelium, and lens. This crucial yet deceptively simple hemispherical structure lays the foundation for all later elaborations of the eye. Building on descriptions of the embryonic eye that started with hand drawings and micrographs, the field is beginning to identify mechanisms driving dynamic changes in three-dimensional cell and tissue shape. A combination of molecular genetics, imaging, and pharmacological approaches is defining connections among transcription factors, signaling pathways, and the intracellular machinery governing the emergence of this crucial structure.

Ocular blood vessel arrangement in choroidal coloboma

OBJECTIVE

To describe the ocular blood vessel arrangement in choroidal coloboma eyes.

METHODS

In this retrospective, observational cross-sectional study, fundus images from 69 coloboma eyes of 45 patients were classified as per Ida Mann's classification. The arrangement and distribution of retinal, choroidal, and episcleral vessels, as well as vortex veins, were observed in non-colobomatous, colobomatous, and extra-colobomatous regions.

RESULTS

Seventy-eight colobomas were identified. There were 12 type 1, 13 type 2, 10 type 3, 13 type 4, 11 type 5, 4 type 6 and 15 type 7 colobomas respectively. In most cases of type 1 and 2 colobomas, origin of retinal blood vessels could not be determined. In colobomas type 3-7, retinal blood vessels originated either from the optic disc centre or, rarely, from the optic disc or coloboma margin. Eyes with large and deep type 1, 2, 3 and 7 colobomas showed prominent choroidal vessels in the non-colobomatous region and around the coloboma. Small choroidal colobomas lacked prominent choroidal vessels. Similarly, prominent extraocular episcleral vessels within the coloboma bed were observed in eyes with colobomas of types 1, 2, 3 and 7. Vortex veins were visible in 70% of coloboma eyes. They were more commonly seen with small focal colobomas and less frequently with large deep colobomas.

CONCLUSION

Coloboma eyes have variations in the arrangement and distribution of ocular blood vessels. The position, size, and antero-posterior extent of the choroidal coloboma are the primary determinants of how these blood vessels are arranged. Future research would benefit from additional imaging with indocyanine green angiography.

Unilateral Lens Coloboma With Congenital Cataract: A Case Report From Central India

A ten-year-old male child was referred with complaints of blurring of vision and deviation of the eye. On examination, the right eye has an esodeviation squint with a best corrected visual acuity of 6/60 Snellen's acuity and 6/6 Snellen's acuity in the left eye. Slit-lamp biomicroscope of the right eye showed coloboma at the 9 o'clock position with cataract. The rest of the anterior and posterior segments was normal in both eyes. Thus, a diagnosis of unilateral lens coloboma with amblyopia was made.

Lens Coloboma: A Rare Association of Congenital Rubella Syndrome

Congenital rubella syndrome (CRS) may affect all ocular structures in general, either in isolation or in combination. Typical ocular complications in CRS include cataracts, microcornea, microphthalmia, glaucoma, nystagmus, and retinopathy. We report a case of a four-year-old girl who presented with bilateral total cataracts with sensory nystagmus, a poorly dilating pupil, iris hypoplasia, high axial myopia in the right eye (RE), and a retinal detachment in the left eye (LE). The systemic evaluation revealed microcephaly with an associated patent ductus arteriosus (PDA) and mild pulmonary arterial hypertension (PAH). Based on these findings, the child was diagnosed with clinically confirmed CRS. The child was taken up for right-eye cataract surgery. Intra-operatively, a lens coloboma involving the temporal equator of the lens along with a highly tessellated fundus was noted. Two weeks post-cataract surgery, the child had a best corrected visual acuity (BCVA) of 6/24. However, four weeks after the surgery, the child developed total rhegmatogenous retinal detachment in the right eye, for which pars plana vitrectomy with endolaser and silicon oil tamponade was done. Four weeks later, the child's BCVA in the right eye was 6/36, which was maintained until the last follow-up of four months. Lens coloboma may be isolated or may occur in association with chorioretinal coloboma. Ours is the first case of unilateral atypical lens coloboma associated with high myopia and bilateral cataracts in a patient with congenital rubella syndrome. Lens colobomas with high myopia have not been reported previously as ocular associations of CRS. Our case highlights that in children with CRS presenting with unilateral or bilateral congenital cataracts, the possibility of lenticular coloboma as a coexistent association should be kept in mind while taking these cases for cataract surgery.

LASER PHOTOCOAGULATION FOR THE TREATMENT OF OPTIC NERVE HEAD PIT-RELATED MACULOPATHY IN A PATIENT WITH BILATERAL CHORIORETINAL COLOBOMA

PURPOSE

To report a case of laser photocoagulation for the treatment of a combined coloboma and optic nerve head pit-related maculopathy in a patient with bilateral chorioretinal coloboma.

METHODS

A case report.

RESULTS

A 15-year-old woman, presented with the visual acuity of 20/100 in her right eye for six weeks. She was diagnosed with macular detachment secondary to optic nerve head pit in her right eye and bilateral chorioretinal coloboma. Multimodal imaging, including color photography, fluorescein angiography, and spectral-domain optical coherence tomography, was used to identify and demonstrate the location of the tract of fluid from the optic nerve head pit, isolated from the coloboma. Optical coherence tomography-guided laser photocoagulation treatment at the location of the tract resulted in complete resolution of macular fluid with visual recovery to 20/25.

CONCLUSION

Our case stresses the value of correct diagnosis directing photocoagulation treatment of combined optic nerve head pit-related maculopathy in eyes with chorioretinal coloboma using multimodal imaging.

Cell fate decisions, transcription factors and signaling during early retinal development

The development of the vertebrate eyes is a complex process starting from anterior-posterior and dorso-ventral patterning of the anterior neural tube, resulting in the formation of the eye field. Symmetrical separation of the eye field at the anterior neural plate is followed by two symmetrical evaginations to generate a pair of optic vesicles. Next, reciprocal invagination of the optic vesicles with surface ectoderm-derived lens placodes generates double-layered optic cups. The inner and outer layers of the optic cups develop into the neural retina and retinal pigment epithelium (RPE), respectively. In vitro produced retinal tissues, called retinal organoids, are formed from human pluripotent stem cells, mimicking major steps of retinal differentiation in vivo. This review article summarizes recent progress in our understanding of early eye development, focusing on the formation the eye field, optic vesicles, and early optic cups. Recent single-cell transcriptomic studies are integrated with classical in vivo genetic and functional studies to uncover a range of cellular mechanisms underlying early eye development. The functions of signal transduction pathways and lineage-specific DNA-binding transcription factors are dissected to explain cell-specific regulatory mechanisms underlying cell fate determination during early eye development. The functions of homeodomain (HD) transcription factors Otx2, Pax6, Lhx2, Six3 and Six6, which are required for early eye development, are discussed in detail. Comprehensive understanding of the mechanisms of early eye development provides insight into the molecular and cellular basis of developmental ocular anomalies, such as optic cup coloboma. Lastly, modeling human development and inherited retinal diseases using stem cell-derived retinal organoids generates opportunities to discover novel therapies for retinal diseases.

The Vascular Pattern In Vicinity Of Chorioretinal Coloboma: An Optical Coherence Tomography Angiography Study

BACKGROUND

Chorioretinal coloboma is a congenital anomaly which can be present in a clinical spectrum with a possibility of significant influence on visual acuity. Optical coherence tomography (OCT) has been frequently used for the study of chorioretinal coloboma. OCT angiography (OCTA), as a non-invasive method of taking high-resolution images of chorioretinal vessels, can improve our understanding of developmental aspects of this anomaly.

MATERIALS AND METHODS

This observational case series evaluated patients with chorioretinal coloboma, who were referred to the eye clinic of a university-based hospital between March 2018 and October 2019. All patients underwent comprehensive ocular examination, OCT, and OCTA using AngioVue technologies from the colobomatous sites.

RESULTS

This study included OCTA imaging of five patients (six eyes) with chorioretinal coloboma lesions. Large retinal vessels, which were intact in all eyes, coursed through the coloboma in four cases and around the margin of the involved area in one case. Attenuation of the microvasculature in the vicinity of coloboma with various extents from nearly normal to severe attenuation was evident in OCTA. Five eyes of four patients had disorganized superficial vessel plexus. Also corkscrew vessels were found in one eye.

CONCLUSIONS

This is the first study assessing the vascular pattern in the vicinity of chorioretinal coloboma using OCTA. OCTA revealed nearly normal to severely attenuated retinal microvasculature. At the same time, intact large retinal vessels at the level of superficial vessel plexus coursed across or around the coloboma. OCTA imaging adds new insights about vascular characteristics in the vicinity of these lesions.

Loss of zebrafish dzip1 results in inappropriate recruitment of periocular mesenchyme to the optic fissure and ocular coloboma

Cilia are essential for the development and function of many different tissues. Although cilia machinery is crucial in the eye for photoreceptor development and function, a role for cilia in early eye development and morphogenesis is still somewhat unclear: many zebrafish cilia mutants retain cilia at early stages due to maternal deposition of cilia components. An eye phenotype has been described in the mouse Arl13 mutant, however, zebrafish arl13b is maternally deposited, and an early role for cilia proteins has not been tested in zebrafish eye development. Here we use the zebrafish dzip1 mutant, which exhibits a loss of cilia throughout stages of early eye development, to examine eye development and morphogenesis. We find that in dzip1 mutants, initial formation of the optic cup proceeds normally, however, the optic fissure subsequently fails to close and embryos develop the structural eye malformation ocular coloboma. Further, neural crest cells, which are implicated in optic fissure closure, do not populate the optic fissure correctly, suggesting that their inappropriate localization may be the underlying cause of coloboma. Overall, our results indicate a role for dzip1 in proper neural crest localization in the optic fissure and optic fissure closure.

Ocular Coloboma With Choroidal Neovascular Membrane: A Case Report

Ocular coloboma (OC) is a rare congenital anomaly and a product of a defect in embryogenesis. It is the result of fetal fissure closure error that ends with a persistent cleft. Colobomas are generally accompanied by visual loss. In this article, we present a case of bilateral iris, disc, and retina coloboma that was managed with an anti-vascular endothelial growth factor (ranibizumab), and as a result, caused regression of the choroidal neovascular membranes and improved the patient's visual acuity. However, The patient will need lifelong follow-up to catch any retinochoroidal changes or development of cataract or glaucoma.

Pax2a, but not pax2b, influences cell survival and periocular mesenchyme localization to facilitate zebrafish optic fissure closure

Background

Pax2 is required for optic fissure development in many organisms, including humans and zebrafish. Zebrafish loss‐of‐function mutations in pax2a display coloboma, yet the etiology of the morphogenetic defects is unclear. Further, pax2 is duplicated in zebrafish, and a role for pax2b in optic fissure development has not been examined.

Results

Using a combination of imaging and molecular genetics, we interrogated a potential role for pax2b and examined how loss of pax2 affects optic fissure development. Although optic fissure formation appears normal in pax2 mutants, an endothelial‐specific subset of periocular mesenchyme (POM) fails to initially localize within the optic fissure, yet both neural crest and endothelial‐derived POM ectopically accumulate at later stages in pax2a and pax2a; pax2b mutants. Apoptosis is not up‐regulated within the optic fissure in pax2 mutants, yet cell death is increased in tissues outside of the optic fissure, and when apoptosis is inhibited, coloboma is partially rescued. In contrast to pax2a, loss of pax2b does not appear to affect optic fissure morphogenesis.

Conclusions

Our results suggest that pax2a, but not pax2b, supports cell survival outside of the optic fissure and POM abundance within it to facilitate optic fissure closure.

Zebrafish pax2a null mutants display a defect in optic fissure closure and coloboma

Loss of pax2b does not affect optic fissure development

An endothelial‐specific subset of periocular mesenchyme cells fails to initially localize to the optic fissure in pax2a mutants

At a later stage of optic fissure development both neural crest and endothelial‐derived periocular mesenchyme ectopically accumulate within the optic fissure

Pax2a mutants have increased apoptosis in surrounding tissues, but not within the optic fissure margin cells, and apoptosis in part underlies the coloboma phenotype

Outcomes of manual small incision cataract surgery and phacoemulsification in eyes with chorioretinal coloboma

PURPOSE

To evaluate outcomes of manual small-incision cataract surgery (MSICS) and phacoemulsification in eyes with chorioretinal coloboma.

SETTING

Tertiary eye center, South India.

DESIGN

Retrospective study.

METHODS

Electronic medical records of 71 patients with chorioretinal coloboma undergoing cataract surgery from January 2017 to December 2019 were evaluated. Demographics, corrected distance visual acuity (CDVA), slitlamp biomicroscopy findings, grade of cataract, type of coloboma and associated posterior segment pathology, outcomes of different surgical techniques and risk factors for poor visual outcomes, and intraoperative complications were analyzed.

RESULTS

Among the 78 eyes studied, 53.9% eyes achieved visual outcome of 20/40 or greater and 20.5% eyes achieved CDVA less than 20/200. For the MSICS group, the median preoperative CDVA was 1.78 (interquartile range [IQR] 1.08 to 2.60) logMAR), which improved to 0.60 (IQR 0.30-1.08) logMAR postoperatively. In phacoemulsification group, the CDVA improved from 0.78 (IQR 0.60-1.00) logMAR to 0.18 (IQR 0.18-0.30) logMAR. Statistically significant visual improvement was noticed in both groups (P < .001 in both). However, eyes that underwent phacoemulsification showed better visual recovery (P < .001). The mean age at presentation was 49.7 ± 10.8 years. MSICS was the most commonly performed surgery (61.54%), and 62 eyes had uneventful cataract surgery. Twelve eyes in MSICS group and 4 eyes in phacoemulsification group had intraoperative complications. Poor visual outcome was associated with male sex, microcornea, hard cataracts, and macular involvement of coloboma.

CONCLUSIONS

MSICS is an alternative to phacoemulsification in colobomatous eyes with advanced cataract. Hard cataract and microcornea were risk factors for intraoperative complications. Significant postoperative improvement in CDVA was noticed in both macula involved and macula not involved groups.

"HOURGLASS COLOBOMA": A CASE REPORT AND REVIEW OF ETIOPATHOGENESIS

PURPOSE

To report a rare case of multiple fundal colobomata and to review the possible etiopathogenic factors involved in its genesis.

METHOD

Case report.

RESULT

A 21-year-old myopic lady was noted to have 2 fundal colobomata-one in the inferior and the other in superior hemisphere of globe in a mirror-image fashion resembling an "hourglass" in the right eye and a typical Type 3 coloboma in the left eye. The iris was normal in both the eye. Multiple fundal colobomata have not been described in the literature. The presence of "accessory embryonic fissure" in the developing eyeball is the only probable mechanism that can explain this presentation. This case is an evidence for the possibility of presence of accessory embryonic fissure in developing eyeball in human. The eponym "hourglass coloboma" or "mirror-image colobomata" best describes this condition.

CONCLUSION

This report of multiple fundal colobomata is the first of its kind. This case is an evidence for possibility of presence of accessory embryonic fissure in developing eyeball in human.

Optical changes and apparent emmetropization in a patient with a peripheral unilateral lens coloboma

Lens coloboma is a developmental defect resulting from abnormalities of the zonules and ciliary body. It may present as an isolated pathology or be accompanied by anomalies in different ocular structures. We report the case of a 20-year-old man referred for evaluation of anisometropic amblyopia in the right eye. Manifest refraction was -2.25 +3.00 ×35 in the right eye; corrected distance visual acuity, 20/50. Corneal topography revealed regular astigmatism of +2.46 D at 124°, and wavefront aberrometry revealed an irregular internal astigmatism of +6.27 D at 35°. Only after full pupillary dilation was a peripheral lens coloboma observed. This case demonstrates that even minor distortions of clear and normally positioned lenses may lead to amblyopia and raises the possibility that corneal changes may occur developmentally through the process of emmetropization partly to compensate for lenticular astigmatism arising from the coloboma.

Cataract surgery in eyes with associated coloboma: Predictors of outcome and safety of different surgical techniques

Purpose:

The aim of this study was to report the outcome of cataract surgery with different surgical techniques in eyes with coexisting coloboma and to define factors of prognostic importance.

Methods:

Retrospective case sheet review of patients presenting between January 2016 and December 2018, who underwent cataract surgery in eyes with coexisting coloboma.

Results:

Of the 3,30,231 cases operated during the study period, 280 eyes of 276 patients had associated colobomatous malformation. The prevalence of coloboma in eyes undergoing cataract surgery was 0.085%. The mean age of the patients was 46.4 years (range 19 - 88 years). Phacoemulsification (PE) was performed in 130 eyes (46.4%), manual small incision cataract surgery (M-SICS) was done in 115 eyes (41.1%), and 35 eyes (12.5%) underwent intra capsular cataract extraction. Intra-operative complications were noted in 26 (9%) eyes. Incidence of intra-operative and post-operative complications was comparable between PE and M-SICS groups (p = 0.94). The mean corrected distance visual acuity (CDVA) improved from logMAR 1.71 ± 0.62 to 0.87 ± 0.61 (p = 0.00009). On multivariate analysis, microcornea (p = 0.002), type 1 and 2 coloboma (p < 0.001), and intraoperative complications (p = 0.001) were associated with poor visual outcome.

Conclusion:

Favorable functional outcomes can be achieved with phacoemulsification in eyes with softer cataract and corneal diameter >8 mm and with M-SICS in eyes with hard cataracts and corneal diameter of 6–8 mm. PE should be considered as the primary choice whenever permissible by the corneal diameter and severity of nuclear sclerosis. Poor functional outcomes were seen in eyes with smaller corneal diameter, extensive chorioretinal coloboma, and intraoperative complications.

Kabuki Syndrome-Clinical Review with Molecular Aspects

Kabuki syndrome (KS) is a rare developmental disorder principally comprised of developmental delay, hypotonia and a clearly defined dysmorphism: elongation of the structures surrounding the eyes, a shortened and depressed nose, thinning of the upper lip and thickening of the lower lip, large and prominent ears, hypertrichosis and scoliosis. Other characteristics include poor physical growth, cardiac, gastrointestinal and renal anomalies as well as variable behavioral issues, including autistic features. De novo or inherited pathogenic/likely pathogenic variants in the KMT2D gene are the most common cause of KS and account for up to 75% of patients. Variants in KDM6A cause up to 5% of cases (X-linked dominant inheritance), while the etiology of about 20% of cases remains unknown. Current KS diagnostic criteria include hypotonia during infancy, developmental delay and/or intellectual disability, typical dysmorphism and confirmed pathogenic/likely pathogenic variant in KMT2D or KDM6A. Care for KS patients includes the control of physical and psychomotor development during childhood, rehabilitation and multi-specialist care. This paper reviews the current clinical knowledge, provides molecular and scientific links and sheds light on the treatment of Kabuki syndrome individuals.

Outcomes of the Perplexed Surgical Management of Retinal Detachment in Eyes with Coloboma

Purpose

To determine the anatomical and visual outcomes of retinal detachment in eyes with chorioretinal coloboma managed by pars plana vitrectomy, endolaser photocoagulation and silicone oil (SO) tamponade.

Methods

Retrospective review of 29 eyes of 29 patients with retinal detachment associated with chorioretinal coloboma. All the cases were managed by vitrectomy procedures concluding with SO tamponade. Encircling band was placed based on pre-operative evaluation and/or surgeon’s discretion. Endolaser photocoagulation was applied around the peripheral retina, all around the peripheral breaks and around the colobomatous area. The outcome measures were evaluated with regard to functional and anatomical success.

Results

The average age at the time of surgery was 21.76 ± 9.58 years (range, 10–50 years). The mean follow-up duration was 12.28 ± 4.8 months (range, 6–24 months). Primary attached retina was obtained in 21 / 29 (72.4%) eyes after single surgery. Re-detachment in 8 / 29 (27.6%) eyes which required revision surgery was the most frequent postoperative complication followed by raised intraocular pressure in 4 / 29 (13.8%) with SO in situ. Out of 29 eyes, 23 were followed up after the removal of SO. The mean duration of SO removal was 7.91 ± 3.9 months (range, 4–18 months). Implantation of encircling band, lens removal and cryotherapy provided no added advantage. At the final examination, improvement in vision was observed in 21 (72.4%) eyes and the anatomical attachment of the retina was attained in 27 (93.1%) eyes.

Conclusions

Complete pars plana vitrectomy, endolaser photocoagulation along with SO tamponade is effective for retinal detachment associated with chorioretinal coloboma. This technique improves the anatomical outcome and helps in regaining significant visual acuity.

Transscleral filtration revealing a chorioretinal coloboma

Purpose

We report the case of a 19-year-old patient who presented with an ocular hypotony due to a transscleral filtration through an isolated congenital chorioretinal coloboma in his right eye.

Observations

The initial examination showed a decimal best corrected visual acuity (BCVA) decreased to 0.7 and a marked hypotony. A localized infero-nasal chemosis and a conjunctival hyperemia were observed. The fundus examination showed chorioretinal folds and an edematous disc. In the infero-nasal retinal periphery, a chorioretinal coloboma was seen with a full-thickness scleral defect. Ultrasound biomicroscopy showed the area of the coloboma through which the percolation of fluid occurred.

Conclusions and importance

A favorable outcome was observed within 6 weeks and BCVA improved to 1.0 three months later. The intraocular pressure (IOP) increased to 11 mmHg, but the bleb-like filtration could still be seen together with some persistent chorioretinal folds. Ultrasound Biomicroscopy (UBM) imaging was helpful to understand the mechanism of this uncommon complication of a coloboma.

A molecular and cellular analysis of human embryonic optic fissure closure related to the eye malformation coloboma

Ocular coloboma is a congenital eye malformation, resulting from a failure in optic fissure closure (OFC) and causing visual impairment. There has been little study of the epithelial fusion process underlying closure in the human embryo and coloboma aetiology remains poorly understood. We performed RNAseq of cell populations isolated using laser capture microdissection to identify novel human OFC signature genes and probe the expression profile of known coloboma genes, along with a comparative murine analysis. Gene set enrichment patterns showed conservation between species. Expression of genes involved in epithelial-to-mesenchymal transition was transiently enriched in the human fissure margins during OFC at days 41-44. Electron microscopy and histological analyses showed that cells transiently delaminate at the point of closure, and produce cytoplasmic protrusions, before rearranging to form two continuous epithelial layers. Apoptosis was not observed in the human fissure margins. These analyses support a model of human OFC in which epithelial cells at the fissure margins undergo a transient epithelial-to-mesenchymal-like transition, facilitating cell rearrangement to form a complete optic cup.

Cataract surgery outcomes in eyes with chorioretinal coloboma

PURPOSE

To evaluate the outcomes of cataract surgery in patients with chorioretinal coloboma.

SETTING

Tertiary eyecare center, New Delhi, India.

DESIGN

Retrospective case series.

METHODS

Medical records of patients with chorioretinal coloboma having cataract surgery between January 2016 and May 2018 were reviewed. The corrected distance visual acuity (CDVA), grade of cataract, type of chorioretinal coloboma, type of surgery, postoperative CDVA, and complications were recorded.

RESULTS

Thirty-eight patients with a mean age at surgery of 36.7 years were included. The mean CDVA at presentation was 1.83 logarithm of the minimum angle of resolution [logMAR] ± 0.31 (SD). Advanced nuclear sclerosis occurred in 61.4% of cases and lens subluxation in 10.2% of cases. Phacoemulsification (56.4%) was the most commonly performed cataract surgery followed by lens aspiration (12.8%) and extracapsular cataract surgery (12.8%). Uneventful cataract surgery with intraocular lens (IOL) implantation was performed in 69.2% of cases. Intraoperative complications included 7 cases of bag dialyses, 3 of posterior capsule ruptures, and 1 of capsulorhexis extension. The mean postoperative CDVA at 6 weeks and 1 year was 1.64 ± 0.51 logMAR and 1.51 ± 0.58 logMAR, respectively. Postoperative complications included 11 cases each of raised intraocular pressure and corneal edema; 2 cases each of IOL decentration, capsule phimosis, and corneal edema; and 1 case of posterior capsule opacification. A second intervention was required in 4 cases (2 endothelial keratoplasties, 1 IOL explantation, 1 neodymium:YAG capsulotomy).

CONCLUSIONS

Cataracts in patients with chorioretinal coloboma are usually advanced compared with age-matched patients with senile cataract. Delayed surgery results in suboptimum outcomes; thus, surgery should be scheduled as soon as possible after the cataract is documented.

Atypical presentation of Cat Eye Syndrome in an infant with Peters anomaly and microphthalmia with cyst

PURPOSE

To describe a unique ocular presentation of Cat Eye Syndrome and review the ocular and systemic findings associated with the syndrome.

METHODS

Case report with multimodal imaging.

RESULTS

A newborn female presented with a unilateral Peters anomaly with contralateral microphthalmia with cyst. The patient's other systemic findings included a hypoplastic right heart, persistent ductus arteriosus, intrauterine growth retardation, bilateral anotia, preauricular ear pits and skin tags, micrognathia, hypoplastic female genitalia, and unilateral cranial nerve VII palsy. Chromosomal microarray testing showed tetrasomy of chromosome 22 in the q11.1-q11.21 region consistent with Cat Eye Syndrome. The patient ultimately underwent a successful optical iridectomy on one side and orbitotomy with excision of the cystic mass on the other.

CONCLUSIONS

The co-occurrence of unilateral Peters anomaly with contralateral microphthalmia with cyst in Cat Eye Syndrome is rare and demonstrative of the syndrome's phenotypic variability. The medical and surgical management of these patients may require a multidisciplinary approach and must be tailored to the individual findings and overall systemic health of the patient.

Ocular coloboma: Genetic variants reveal a dynamic model of eye development

Ocular coloboma is a congenital disorder of the eye where a gap exists in the inferior retina, lens, iris, or optic nerve tissue. With a prevalence of 2-19 per 100,000 live births, coloboma, and microphthalmia, an associated ocular disorder, represent up to 10% of childhood blindness. It manifests due to the failure of choroid fissure closure during eye development, and it is a part of a spectrum of ocular disorders that include microphthalmia and anophthalmia. Use of genetic approaches from classical pedigree analyses to next generation sequencing has identified more than 40 loci that are associated with the causality of ocular coloboma. As we have expanded studies to include singleton cases, hereditability has been very challenging to prove. As such, researchers over the past 20 years, have unraveled the complex interrelationship amongst these 40 genes using vertebrate model organisms. Such research has greatly increased our understanding of eye development. These genes function to regulate initial specification of the eye field, migration of retinal precursors, patterning of the retina, neural crest cell biology, and activity of head mesoderm. This review will discuss the discovery of loci using patient data, their investigations in animal models, and the recent advances stemming from animal models that shed new light in patient diagnosis.

Confirmation of FZD5 implication in a cohort of 50 patients with ocular coloboma

Defects in optic fissure closure can lead to congenital ocular coloboma. This ocular malformation, often associated with microphthalmia, is described in various clinical forms with different inheritance patterns and genetic heterogeneity. In recent times, the identification of an increased number of genes involved in numerous cellular functions has led to a better understanding in optic fissure closure mechanisms. Nevertheless, most of these genes are also involved in wider eye growth defects such as micro-anophthalmia, questioning the mechanisms controlling both extension and severity of optic fissure closure defects. However, some genes, such as FZD5, have only been so far identified in isolated coloboma. Thus, to estimate the frequency of implication of different ocular genes, we screened a cohort of 50 patients affected by ocular coloboma by using targeted sequencing of 119 genes involved in ocular development. This analysis revealed seven heterozygous (likely) pathogenic variants in RARB, MAB21L2, RBP4, TFAP2A, and FZD5. Surprisingly, three out of the seven variants detected herein were novel disease-causing variants in FZD5 identified in three unrelated families with dominant inheritance. Although molecular diagnosis rate remains relatively low in patients with ocular coloboma (14% (7/50) in this work), these results, however, highlight the importance of genetic screening, especially of FZD5, in such patients. Indeed, in our series, FZD5 variants represent half of the genetic causes, constituting 6% (3/50) of the patients who benefited from a molecular diagnosis. Our findings support the involvement of FZD5 in ocular coloboma and provide clues for screening this gene during current diagnostic procedures.

Mitf-family transcription factor function is required within cranial neural crest cells to promote choroid fissure closure

A crucial step in eye development is the closure of the choroid fissure (CF), a transient structure in the ventral optic cup through which vasculature enters the eye and ganglion cell axons exit. Although many factors have been identified that function during CF closure, the molecular and cellular mechanisms mediating this process remain poorly understood. Failure of CF closure results in colobomas. Recently, MITF was shown to be mutated in a subset of individuals with colobomas, but how MITF functions during CF closure is unknown. To address this issue, zebrafish with mutations in mitfa and tfec, two members of the Mitf family of transcription factors, were analyzed and their functions during CF closure determined. mitfa;tfec mutants possess severe colobomas and our data demonstrate that Mitf activity is required within cranial neural crest cells (cNCCs) during CF closure. In the absence of Mitf function, cNCC migration and localization in the optic cup are perturbed. These data shed light on the cellular mechanisms underlying colobomas in individuals with MITF mutations and identify a novel role for Mitf function in cNCCs during CF closure.

In Vivo Analysis of Optic Fissure Fusion in Zebrafish: Pioneer Cells, Basal Lamina, Hyaloid Vessels, and How Fissure Fusion is Affected by BMP

Colobomata, persistent optic fissures, frequently cause congenital blindness. Here, we focused on optic fissure fusion using in vivo time-lapse imaging in zebrafish. We identified the fusion initiating cells, which we termed “pioneer cells.” Based on morphology, localization, and downregulation of the neuroretinal (NR) precursor marker rx2, these cells could be considered as retinal pigment epithelial (RPE) progenitors. Notably, pioneer cells regain rx2 expression and integrate into the NR after fusion, indicating that they do not belong to the pool of RPE progenitors, supported by the lack of RPE marker expression in pioneer cells. They establish the first cellular contact between the margins in the proximal fissure region and separate the hyaloid artery and vein. After initiation, the fusion site is progressing distally, increasing the distance between the hyaloid artery and vein. A timed BMP (Bone Morphogenetic Protein) induction, resulting in coloboma, did not alter the morphology of the fissure margins, but it did affect the expression of NR and RPE markers within the margins. In addition, it resulted in a persisting basal lamina and persisting remnants of periocular mesenchyme and hyaloid vasculature within the fissure, supporting the necessity of BMP antagonism within the fissure margins. The hampered fissure fusion had severe effects on the vasculature of the eye.

Morphogenesis and axis specification occur in parallel during optic cup and optic fissure formation, differentially modulated by BMP and Wnt

Optic cup morphogenesis is an intricate process. Especially, the formation of the optic fissure is not well understood. Persisting optic fissures, termed coloboma, are frequent causes for congenital blindness. Even though the defective fusion of the fissure margins is the most acknowledged reason for coloboma, highly variable morphologies of coloboma phenotypes argue for a diverse set of underlying pathomechanisms. Here, we investigate optic fissure morphogenesis in zebrafish to identify potential morphogenetic defects resulting in coloboma. We show that the formation of the optic fissure depends on tissue flow movements, integrated into the bilateral distal epithelial flow forming the optic cup. On the temporal side, the distal flow translates into a ventral perpendicular flow, shaping the temporal fissure margin. On the nasal side, however, the distal flow is complemented by tissue derived from the optic stalk, shaping the nasal fissure margin. Notably, a distinct population of TGFβ-signalling positive cells is translocated from the optic stalk into both fissure margins. Furthermore, we show that induced BMP signalling as well as Wnt-signalling inhibition result in morphogenetic defects of the optic fissure. Our data also indicate that morphogenesis is crucial for a proper positioning of pre-specified dorsal–ventral optic cup domains.

High-throughput custom capture sequencing identifies novel mutations in coloboma-associated genes: Mutation in DNA-binding domain of retinoic acid receptor beta affects nuclear localization causing ocular coloboma

Uveal coloboma is a potentially blinding congenital ocular malformation caused by the failure of optic fissure closure during the fifth week of human gestation. We performed custom capture high‐throughput screening of 38 known coloboma‐associated genes in 66 families. Suspected causative novel variants were identified in TFAP2A and CHD7, as well as two previously reported variants of uncertain significance in RARB and BMP7. The variant in RARB, unlike previously reported disease mutations in the ligand‐binding domain, was a missense change in the highly conserved DNA‐binding domain predicted to affect the protein's DNA‐binding ability. In vitro studies revealed lower steady‐state protein levels, reduced transcriptional activity, and incomplete nuclear localization of the mutant RARB protein compared with wild‐type. Zebrafish studies showed that human RARB messenger RNA partially reduced the ocular phenotype caused by morpholino knockdown of rarga gene, a zebrafish homolog of human RARB. Our study indicates that sequence alterations in known coloboma genes account for a small percentage of coloboma cases and that mutations in the RARB DNA‐binding domain could result in human disease.

Maternal Inheritance of a Recessive RBP4 Defect in Canine Congenital Eye Disease

Maternally skewed transmission of traits has been associated with genomic imprinting and oocyte-derived mRNA. We report canine congenital eye malformations, caused by an amino acid deletion (K12del) near the N terminus of retinol-binding protein (RBP4). The disease is only expressed when both dam and offspring are deletion homozygotes. RBP carries vitamin A (retinol) from hepatic stores to peripheral tissues, including the placenta and developing eye, where it is required to synthesize retinoic acid. Gestational vitamin A deficiency is a known risk factor for ocular birth defects. The K12del mutation disrupts RBP folding in vivo, decreasing its secretion from hepatocytes to serum. The maternal penetrance effect arises from an impairment in the sequential transfer of retinol across the placenta, via RBP encoded by maternal and fetal genomes. Our results demonstrate a mode of recessive maternal inheritance, with a physiological basis, and they extend previous observations on dominant-negative RBP4 alleles in humans.

Optic Disc Coloboma in children - prevalence, clinical characteristics and associated morbidity

PURPOSE

The aim of the study was to report prevalence, ocular outcome, neurological characteristics, cognitive and behavioural problems in children with optic disc coloboma (ODC).

METHODS

This was a population-based, cross-sectional study of 31 children between 2 and 18 years of age diagnosed with ODC. The children were part of a larger cohort of 184 children with congenital optic disc malformations. Clinical ophthalmological examinations, neurological assessments, behavioural and developmental screening were performed.

RESULTS

The prevalence of ODC was 8.9/100 000 children. Of the 31 patients, 18 had unilateral ODC (p = 0.21). The best-corrected visual acuity (BCVA) in the ODC eye ranged from blindness to 1.3 (median 0.3). BCVA was 0.82 in eyes with an isolated ODC (range 0.4-1.3) and 0.15 (range 0-0.5) in eyes with concurrent macular involvement (p < 0.0001). Nystagmus was observed more often in patients with bilateral ODC (9/13 versus 3/17, p = 0.004). Two patients had retinal detachment. Behavioural/psychological screening was performed in 21 patients with severe deficits identified in six cases. Intellectual disability was present in seven patients. Neurological dysfunction was diagnosed in 8/22 cases. All of the above children had already systemic diagnoses before the ODC diagnosis was made.

CONCLUSIONS

ODC was the second most common optic disc malformation in this cohort after optic nerve hypoplasia. The children had a wide range of ocular comorbidity. An isolated ODC without macular involvement was not associated with profound vision loss. The ability of screening in the regular child care centres to diagnose extraocular comorbidities was very good and referral to a paediatrician appears redundant in cases of normal development.

Detailed analysis of chick optic fissure closure reveals Netrin-1 as an essential mediator of epithelial fusion

Epithelial fusion underlies many vital organogenic processes during embryogenesis. Disruptions to these cause a significant number of human birth defects, including ocular coloboma. We provide robust spatial-temporal staging and unique anatomical detail of optic fissure closure (OFC) in the embryonic chick, including evidence for roles of apoptosis and epithelial remodelling. We performed complementary transcriptomic profiling and show that Netrin-1 (NTN1) is precisely expressed in the chick fissure margin during fusion but is immediately downregulated after fusion. We further provide a combination of protein localisation and phenotypic evidence in chick, humans, mice and zebrafish that Netrin-1 has an evolutionarily conserved and essential requirement for OFC, and is likely to have an important role in palate fusion. Our data suggest that NTN1 is a strong candidate locus for human coloboma and other multi-system developmental fusion defects, and show that chick OFC is a powerful model for epithelial fusion research.

Our bodies are made of many different groups of cells, which are arranged into tissues that perform specific roles. As tissues form in the embryo they must adopt precise three-dimensional structures, depending on their position in the body. In many cases this involves two edges of tissue fusing together to prevent gaps being present in the final structure.

In individuals with a condition called ocular coloboma some of the tissues in the eyes fail to merge together correctly, leading to wide gaps that can severely affect vision. There are currently no treatments available for ocular coloboma and in over 70% of patients the cause of the defect is not known. Identifying new genes that control how tissues fuse may help researchers to find what causes this condition and multiple other tissue fusion defects, and establish whether these may be preventable in the future.

Much of what is currently known about how tissues fuse has come from studying mice and zebrafish embryos. Although the extensive genetic tools available in these ‘models’ have proved very useful, both offer only a limited time window for observing tissues as they fuse, and the regions involved are very small. Chick embryos, on the other hand, are much larger than mouse or zebrafish embryos and are easier to access from within their eggs. This led Hardy et al. to investigate whether the developing chick eye could be a more useful model for studying the precise details of how tissues merge.

Examining chick embryos revealed that tissues in the base of their eyes fuse between five and eight days after the egg had been fertilised, a comparatively long time compared to existing models. Also, many of the genes that Hardy et al. found switched on in chick eyes as the tissues merged had previously been identified as being essential for tissue fusion in humans. However, several new genes were also shown to be involved in the fusing process. For example, Netrin-1 was important for tissues to fuse in the eyes as well as in other regions of the developing embryo.

These findings demonstrate that the chick eye is an excellent new model system to study how tissues fuse in animals. Furthermore, the genes identified by Hardy et al. may help researchers to identify the genetic causes of ocular coloboma and other tissue fusion defects in humans.

An update on the genetics of ocular coloboma

Ocular coloboma is an uncommon, but often severe, sight-threatening condition that can be identified from birth. This congenital anomaly is thought to be caused by maldevelopment of optic fissure closure during early eye morphogenesis. It has been causally linked to both inherited (genetic) and environmental influences. In particular, as a consequence of work to identify genetic causes of coloboma, new molecular pathways that control optic fissure closure have now been identified. Many more regulatory mechanisms still await better understanding to inform on the development of potential therapies for patients with this malformation. This review provides an update of known coloboma genes, the pathways they influence and how best to manage the condition. In the age of precision medicine, determining the underlying genetic cause in any given patient is of high importance.

TGFβ-facilitated optic fissure fusion and the role of bone morphogenetic protein antagonism

The optic fissure is a transient gap in the developing vertebrate eye, which must be closed as development proceeds. A persisting optic fissure, coloboma, is a major cause for blindness in children. Although many genes have been linked to coloboma, the process of optic fissure fusion is still little appreciated, especially on a molecular level. We identified a coloboma in mice with a targeted inactivation of transforming growth factor β2 (TGFβ2). Notably, here the optic fissure margins must have touched, however failed to fuse. Transcriptomic analyses indicated an effect on remodelling of the extracellular matrix (ECM) as an underlying mechanism. TGFβ signalling is well known for its effect on ECM remodelling, but it is at the same time often inhibited by bone morphogenetic protein (BMP) signalling. Notably, we also identified two BMP antagonists among the downregulated genes. For further functional analyses we made use of zebrafish, in which we found TGFβ ligands expressed in the developing eye, and the ligand binding receptor in the optic fissure margins where we also found active TGFβ signalling and, notably, also gremlin 2b (grem2b) and follistatin a (fsta), homologues of the regulated BMP antagonists. We hypothesized that TGFβ is locally inducing expression of BMP antagonists within the margins to relieve the inhibition from its regulatory capacity regarding ECM remodelling. We tested our hypothesis and found that induced BMP expression is sufficient to inhibit optic fissure fusion, resulting in coloboma. Our findings can likely be applied also to other fusion processes, especially when TGFβ signalling or BMP antagonism is involved, as in fusion processes during orofacial development.

Transcriptome profiling of zebrafish optic fissure fusion

Incomplete fusion of the optic fissure leads to ocular coloboma, a congenital eye defect that affects up to 7.5 per 10,000 births and accounts for up to 10 percent of childhood blindness. The molecular and cellular mechanisms that facilitate optic fissure fusion remain elusive. We have profiled global gene expression during optic fissure morphogenesis by transcriptome analysis of tissue dissected from the margins of the zebrafish optic fissure and the opposing dorsal retina before (32 hours post fertilisation, hpf), during (48 hpf) and after (56 hpf) optic fissure fusion. Differential expression analysis between optic fissure and dorsal retinal tissue resulted in the detection of several known and novel developmental genes. The expression of selected genes was validated by qRT-PCR analysis and localisation investigated using in situ hybridisation. We discuss significantly overrepresented functional ontology categories in the context of optic fissure morphogenesis and highlight interesting transcripts from hierarchical clustering for subsequent analysis. We have identified netrin1a (ntn1a) as highly differentially expressed across optic fissure fusion, with a resultant ocular coloboma phenotype following morpholino antisense translation-blocking knockdown and downstream disruption of atoh7 expression. To support the identification of candidate genes in human studies, we have generated an online open-access resource for fast and simple quantitative querying of the gene expression data. Our study represents the first comprehensive analysis of the zebrafish optic fissure transcriptome and provides a valuable resource to facilitate our understanding of the complex aetiology of ocular coloboma.

[Bilateral chorioretinian colobome: about a case]

La présence d'un colobome choriorétinien soulève souvent des problèmes cliniques entraînant parfois une certaine confusion. Néanmoins, le diagnostic se doit d'être aussi précis que possible pour plusieurs raisons. L'association de certaines anomalies congénitales de la papille avec d'autres pathologies neurologiques endocriniennes ou systémiques et le problème de diagnostic différentiel avec d'autres pathologies ophtalmologiques. Nous rapportons un cas clinique d'un enfant âgé de 6 ans, le premier garçon d'une famille de 2 enfants présentant un colobome papillaire bilatéral sans d'autres anomalies malformatives associées. Dans ses antécédents: sont accouchement s'est déroulé normalement et sont statut vaccinal été à jour. L'examen ophtalmologique de son père et de sa petite sœur âgée de 4 ans été sans particularité, cependant sa mère présente un strabisme divergent à l'œil droit.

Surgical technique for management of isolated lenticular coloboma with high corneal astigmatism

We describe a surgical technique for the correction of isolated congenital lenticular coloboma associated with high corneal astigmatism. Transscleral fixation of the capsular bag with a single eyelet Cionni capsular tension ring was followed by in-the-bag implantation of a toric intraocular lens (IOL). This lead to complete correction of the lenticular defect and perfect alignment of the toric lens. In this case, the child attained an unaided distance visual acuity of 20/30 following amblyopia therapy and a well-aligned toric IOL at 12 months of follow-up. This technique can be used in cases with concomitant lenticular coloboma and significant corneal astigmatism.

Ocular Manifestations of a Novel Proximal 19p13.3 Microdeletion

Microdeletions at 19p13.3 are rarely reported in the medical literature with significant phenotypic variability. Among the reported cases, common clinical manifestations have included developmental delay, facial dysmorphism, and hypotonia. Herein we described a child with a de novo 19p13.3 microdeletion, proximal to the reported cases of 19p13.3 microdeletion/duplication, with ocular manifestations of bilateral ocular colobomata complicated with microphthalmos and cataract, associated with short stature. This case highlights the phenotypic heterogeneity of deletions in the 19p13.3 region.

Low-vision aids improve the visual performance of children with bilateral chorioretinal coloboma

PURPOSE

To quantify the improvements in visual performance for both distance and near tasks attained by children with bilateral chorioretinal coloboma (CRC) with use of low-vision aids (LVAs).

METHODS

This was a hospital-based, cross-sectional, interventional case series of children with bilateral CRC. Demographic data were collected through a structured questionnaire and review of medical records. Distance and near best-corrected visual acuity, contrast sensitivity, and reading speed were evaluated with refractive correction alone and with the use of LVAs (Keplerian telescopes for distance; handheld magnifiers and a tinted lens [400 nm filter] for near). Effects are presented as medians of differences with 95% binomial-exact confidence intervals.

RESULTS

Six children were included (median age, 11.5 years; range, 7-17 years), of whom 5 were already using LVAs on a daily basis. The use of a Keplerian telescope achieved a significant median improvement in distance best-corrected visual acuity of 0.75 logMAR (95% CI, 0.20-1.20). Contrast sensitivity was also improved across all tested spatial frequencies. Use of near LVAs resulted in a significant median improvement in near reading acuity of 0.47 logRAD (95% CI, 0.28-0.90). Critical print size and reading speed at N10 were also improved.

CONCLUSIONS

LVAs enable meaningful improvements in the visual performance of children with bilateral CRC, allowing noteworthy increases in distance and near visual acuities as well as good reading speeds at small print sizes.