Ocular signs, visual and general developmental outcome in Indian children with radiologically proven periventricular leukomalacia.

PURPOSE: Owing to the paucity of literature on Indian children with periventricular leukomalacia (PVL), this retrospective study aimed to describe the visual and associated developmental abnormalities in a series of affected children attending a tertiary level eye care facility. METHODS: Children with radiologically confirmed PVL who attended the Pediatric Department of a tertiary eye hospital were included and underwent a detailed ocular and general developmental assessment. RESULTS: Of the 75 children, the mean age was 2.3 years, the mean follow-up was 3.1 years, 68% were males and 43% were born preterm. Grade I PVL was identified in 13 children (17%), Grade 2 PVL in 39 (52%), and Grade 3 PVL in 23 (31%). Premies with ≤2 kg (72.5%) and term babies with >2 kg (75%) had a greater association of PVL occurrence with a preponderance to severe PVL; 46% of the children were visually impaired which was significantly higher in the children with Grade 3 PVL (74%) than those with Grade 2 PVL (15%). Strabismus was common (80%) with a change in deviation over time. Seventy-one percent of the children had a refractive error, frequently myopic astigmatism. All the children except two had a delay in one or more general developmental milestones. CONCLUSION: PVL occurrence is observed both in the babies born at term and premies, resulting in significant ocular and systemic morbidities. We recommend a system in place for early identification and referral to initiate an early intervention program which goes a long way toward improving the quality of life in these children.

Down syndrome with bilateral posterior lenticonus.

We present a case of bilateral posterior lenticonus in a young boy with Down syndrome. Association of posterior lenticonus in Down syndrome is rarely reported in the literature. We have discussed the clinical features and management of this patient at our hospital.

Ocular Morbidity Associated With Retinopathy of Prematurity in Treated and Untreated Eyes: A Review of the Literature and Data From a Tertiary Eye-care Center in Southern India.

Retinopathy of prematurity (ROP) is an emerging cause of childhood blindness in low- and middle-income countries. We review the magnitude, causes, prevention and treatment of visual impairment caused by ROP over a time span. A review of literature on short and long term structural and functional outcomes of ROP was conducted through PubMed search primarily focusing on studies published during the last decade. Additionally, we have shared data from our institute located in Southern India. Visual Impairment in ROP-treated children ranged from 4.1% to 30% in various settings, attributable mainly to refractive errors, amblyopia, strabismus and perinatal neurological events followed by structural changes like macular scarring and retinal detachment. We conclude that towards an early detection and a proper management of all the above mentioned conditions, these children need to be followed-up for a long time by a committed pediatric ophthalmologist at a specifically scheduled interval. The overall success depends upon the strength of the networking system between parents/neonatologists/pediatricians/pediatric ophthalmologist and a retina specialist.

Double Augmented Vertical Rectus Transposition for Large-Angle Esotropia Due to Sixth Nerve Palsy.

PURPOSE: To study the binocular alignment and ocular motility in patients with large-angle esotropia due to sixth nerve palsy treated with double augmented vertical recti transposition. METHODS: This was a prospective interventional study. Fifteen patients with non-resolving sixth nerve palsy who underwent surgical correction were included in the study. Fourteen patients also underwent an additional medial rectus recession. Two patients with an associated small vertical deviation had a selective augmentation of one vertical rectus muscle. Binocular alignment, ocular motility, duction limitation, improvement in head posture, induced vertical deviations, and field of diplopia-free binocular single vision (when possible) were analyzed. Successful outcome was defined as a residual horizontal deviation of 10 prism diopters (PD) or less with no vertical deviation at final follow-up (6 months). RESULTS: The double augmented Hummelsheim procedure improved esotropia from 58.3 ± 10.8 PD preoperatively to 7.2 ± 5.1 PD postoperatively (P = .001). Three (20%) patients had residual deviation of greater than 10 PD, of which 1 patient had diplopia and was treated with prisms. Postoperative binocular field of vision was performed in 6 patients, the mean of which was 20° for abduction and 45° for adduction. Three of 6 patients had elimination of face turn and the rest had residual head posture of less than 5°. Two patients had an induced vertical deviation of less than 4 PD. In patients who had selective augmentation, the vertical deviation was completely corrected. CONCLUSIONS: The patients operated on with double augmentation of the Hummelsheim procedure combined with medial rectus recession had reduced mean primary esotropia and improved diplopia-free field of vision postoperatively. [J Pediatr Ophthalmol Strabismus. 2016;53(6):369-374.].

Mutational analysis and genotype-phenotype correlations in southern Indian patients with sporadic and familial aniridia.

PURPOSE: Aniridia is a rare panocular disorder characterized by iris hypoplasia and other associated eye anomalies. Heterozygous null mutations in paired box gene 6 (PAX6) are the major cause of the classic aniridia phenotype. This study aims to detect the mutational spectrum of PAX6 and associated phenotypes in southern Indian patients with sporadic and familial aniridia. METHODS: Genomic DNA was isolated from peripheral blood from all participants. The coding regions and flanking intronic sequences of PAX6 were screened with Sanger sequencing in 30 probands with aniridia. The identified variations were further evaluated in available family members and 150 healthy controls. The pathogenic potential of the mutations were assessed using bioinformatics tools. RESULTS: Thirteen different mutations were detected in eight sporadic and five familial cases. Eleven novel mutations, including five insertions (c.7_10dupAACA, c.567dupC, c.704dupC, c.868dupA and c.753_754insTA), two deletions (c.242delC and c.249delT), and four splicing variants (c.10+1G>A, c.141G>A, c.141+4A>G and c.764A>G) were identified in this study. Clinical findings of the patients revealed phenotypic heterogeneity with the same or different mutations. CONCLUSIONS: This study reported 11 novel mutations and thus expanded the spectrum of PAX6 mutations. Interestingly, all mutations reported in this study were truncations, which confirms the hypothesis that haploinsufficiency of PAX6 causes the aniridia phenotype. Our observations revealed inter- and intrafamilial phenotypic variability with PAX6 mutations. The common ocular findings associated with PAX6 mutations were iris hypoplasia, nystagmus, and foveal hypoplasia reported in almost all cases, with cataract, glaucoma, and keratopathy reported in approximately 50% of the patients.

Congenital oculomotor nerve palsy due to effects of carotid artery agenesis.

Isolated carotid artery agenesis is not generally recognized as a cause of congenital oculomotor nerve palsy. We report this rare association in 2 children and examine the underlying mechanism.

Genotype/phenotype association in Indian congenital aniridia.

The developmental birth eye disorder of iris is known as aniridia. Heterozygous PAX6 gene, which causes human aniridia and small eye in mice, is located on chromosome 11p13. The variability had been documented between the affected individuals within the families, is due to genotypic variation. Haploinsufficiency renders PAX6 allele non-functional or amorphic, however it presents hypomorphic or neomorphic alleles. India is not a well-studied ethnic group, hence the focus on congenital aniridia gene analysis supports the literature and the phenotypic association were analysed both in sporadic as well as familial. The consistent association of truncating PAX6 mutations with the phenotype is owing to non-sense-mediated decay (NMD). It is presumed that the genetic impact of increased homozygosity and heterozygocity in Indian counter part arises as the consequence of consanguineous marriages. The real fact involved in congenital aniridia with other related phenotypes with PAX6 mutations are still controversial.

Incomplete penetrance and phenotypic variability characterize Gdf6-attributable oculo-skeletal phenotypes.

Proteins of the bone morphogenetic protein (BMP) family are known to have a role in ocular and skeletal development; however, because of their widespread expression and functional redundancy, less progress has been made identifying the roles of individual BMPs in human disease. We identified seven heterozygous mutations in growth differentiation factor 6 (GDF6), a member of the BMP family, in patients with both ocular and vertebral anomalies, characterized their effects with a SOX9-reporter assay and western analysis, and demonstrated comparable phenotypes in model organisms with reduced Gdf6 function. We observed a spectrum of ocular and skeletal anomalies in morphant zebrafish, the latter encompassing defective tail formation and altered expression of somite markers noggin1 and noggin2. Gdf6(+/-) mice exhibited variable ocular phenotypes compatible with phenotypes observed in patients and zebrafish. Key differences evident between patients and animal models included pleiotropic effects, variable expressivity and incomplete penetrance. These data establish the important role of this determinant in ocular and vertebral development, demonstrate the complex genetic inheritance of these phenotypes, and further understanding of BMP function and its contributions to human disease.

Resolution of anterior segment ischemia after the removal of lateral fixation sutures.

Anterior segment ischemia is a rare but well-recognized complication after strabismus surgery, involving multiple extraocular muscles. We report a case of traumatic left sixth nerve palsy in a 32-year-old man who developed anterior segment ischemia after left medial rectus muscle recession and partial tendon transfer of the vertical rectus muscles to the lateral rectus, augmented by lateral fixation sutures. The corneal edema and anterior chamber reaction cleared upon removal of the lateral fixation sutures and institution of steroids and cycloplegics. The possible role of lateral fixation sutures in anterior segment ischemia is discussed.

Crystallin gene mutations in Indian families with inherited pediatric cataract.

PURPOSE: Pediatric cataract is the most common form of treatable childhood blindness and is both clinically and genetically heterogeneous. Autosomal dominant and recessive forms of cataract have been reported to be caused by mutations in 22 different genes so far. Of the cataract mutations reported to date, about half the mutations occur in crystallins, a quarter of the mutations in connexins, and the remainder is evenly divided between intrinsic membrane proteins, intermediate filament proteins, and transcription factors. This study is aimed at identification of the spectrum and frequency of crystallin gene mutations in cataractous patients in an Indian population. METHODS: Genetic analysis was extended to screen the entire coding region of the CRYAA, CRYAB, CRYBA1, CRYBA4, CRYBB1, CRYBB2, CRYBB3, CRYGC, CRYGD, and CRYGS genes using single stranded conformational polymorphism (SSCP) analysis as a screening technique followed by direct sequencing of all subjects that displayed an electrophoretic shift. RESULTS: This report describes the first simultaneous mutation analysis of 10 crystallin genes in the same population, represented by 60 south Indian families. The analysis allowed the identification of causative mutations in 10 of the families (three novel and six reported). This includes six missense mutations (CRYAA-R12C, R21W, R54C, CRYAB- A171T, CRYGC-R168W, CRYGS- S39C), two nonsense mutations (CRYBB2- Q155X, CRYGD- R140X), and one splice mutation, which was identified in two families (CRYBA1-IVS3+1G>A). CONCLUSIONS: Crystallin mutations are responsible for 16.6% of the inherited pediatric cataract in this population. As causative mutations have not been found in many of the families analyzed, this study suggests the presence of further novel genes or sequence elements involved in the pathogenesis of cataract in these families.

Laboratory confirmation of congenital rubella syndrome in infants: an eye hospital based investigation.

A total of 190 specimens from South Indian children aged 0-59 months with ocular anomalies consistent with suspected congenital rubella syndrome (CRS) were investigated. Twenty-six of the 65 infants (40%) were confirmed as CRS by detection of rubella specific IgM. Rubella RNA was detected in 41 samples from 26 infants by both real-time and block based PCR. The PCR results correlated well with the presence of anti-rubella IgM/IgG (23/27 cases with rubella IgM were PCR positive). Whereas, only 17 of 26 infants met the WHO CRS case definition. Amongst the various specimens tested from the sero-confirmed cases (n = 27), a high percentage of positives were detected in lens (92%) and oral fluid (60%) specimens, when compared to other samples. The quantification of viral load by real-time PCR demonstrated higher copy number of virus in lens samples of 0-11 months infants. The rubella viruses were characterized and revealed the circulation of genotype 2B in three South Indian states. The integrated analysis of clinical manifestations, serological and molecular data in the study has generated baseline information of rubella infection and CRS in infants with ocular anomalies.

Optical iridectomy in children with corneal opacities.

BACKGROUND: Optical iridectomy creates a clear entrance pupil, improving vision in patients with segmental corneal opacities. An area of clear peripheral cornea can produce retinal images compatible with good visual acuity. MATERIALS AND METHODS: The records of 22 children who underwent optical iridectomy from January 2002 to June 2004 were reviewed retrospectively. The optical iridectomy site was selected after slit-lamp examination. Visual acuity was assessed pre- and postoperatively by an age-appropriate method. RESULTS: Twenty-two children with central corneal opacities underwent the procedure. Mean age was 10.4 +/- 12.6 months (range, 8-24 months). Mean follow-up period was 22.2 +/- 56.2 months (range, 8-140 months). No intraoperative or postoperative complications were observed. Visual acuity improved to near normal in 4 children (18.2%). However, 4 children (18.2%) did not show any improvement, and 1 child lost vision. Two patients (9.1%) showed no improvement in vision despite maintaining a clear line of sight. CONCLUSIONS: Optical iridectomy is an alternative when penetrating keratoplasty cannot or should not be performed.

Pigmented free-floating retrolental space cyst.

We report an unusual case of a free-floating pigmented retrolental cyst, which was diagnosed after examination by slitlamp, B-scan ultrasonography, and ultrasound biomicroscopy. Pigmented cysts, which may arise from the ciliary body epithelium, are embryologically and morphologically different from clear cysts.

Electroretinographic assessment and diagnostic reappraisal of children with visual dysfunction: a prospective study.

PURPOSE: To assess the presence or absence of a retinal cause of visual impairment using electroretinography (ERG) in children with no obvious discernable cause on ocular examination. DESIGN: Prospective observational case series. MATERIALS AND METHODS: A prospective study was carried out involving 120 children with the mean age 4.4+/-3.2 years with visual dysfunction. All children underwent ERG under general anesthesia using a special handheld mini-Ganzfeld (Kurbisfeld) dome. RESULTS: Fifty-two (43.3%) children were male and 68 (56.7%) were female. The clinical diagnosis was as follows: Leber's congenital amaurosis (LCA) (n=47), achromatopsia (n=25), congenital stationary night blindness (CSNB) (n=9) and others (unclassifiable, n=39). The visual acuity ranged from perception of light (PL) to PL with projection in children with LCA. In the rest (n=73), some sort of visually guided behavior was discernable. Following ERG, a diagnostic reappraisal resulted as follows: LCA (n=49), achromatopsia (n=28), CSNB (n=4), cone-rod dystrophy (n=22), rod-cone degeneration (n=7), normal (n=8) and others (unclassifiable, n=2). Except for the two unclassifiable cases, ERG was successful in the diagnosis or exclusion of retinal dysfunction in the rest. By Pearson Chi-square test, there was a statistically significant association between the clinical and ERG diagnosis (P < 0.001). CONCLUSION: LCA was the commonest cause of visual dysfunction in our series. A statistically significant correlation between clinical and electrophysiological diagnosis was seen. ERG helped in firmly establishing the presence or absence of global retinal dysfunction in the majority (118/120) of pediatric patients with visual dysfunction.

Retinitis pigmentosa associated with blepharophimosis, blue dot cataract and primary inferior oblique overaction: a new syndrome complex?

A 15-year-old girl with retinitis pigmentosa, blepharophimosis, blue dot cataract and primary overaction of inferior oblique muscle in both the eyes is being reported. Computerized search using Medline did not reveal any such previously reported association.

CRYBA4, a novel human cataract gene, is also involved in microphthalmia.

Genetic analysis of a large Indian family with an autosomal dominant cataract phenotype allowed us to identify a novel cataract gene, CRYBA4. After a genomewide screen, linkage analysis identified a maximum LOD score of 3.20 (recombination fraction [theta] 0.001) with marker D22S1167 of the beta -crystallin gene cluster on chromosome 22. To date, CRYBA4 was the only gene in this cluster not associated with either human or murine cataracts. A pathogenic mutation was identified in exon 4 that segregated with the disease status. The c.317T-->C sequence change is predicted to replace the highly conserved hydrophobic amino acid phenylalanine94 with the hydrophilic amino acid serine. Modeling suggests that this substitution would significantly reduce the intrinsic stability of the crystalline monomer, which would impair its ability to form the association modes critical for lens transparency. Considering that CRYBA4 associates with CRYBB2 and that the latter protein has been implicated in microphthalmia, mutational analysis of CRYBA4 was performed in 32 patients affected with microphthalmia (small eye). We identified a c.242T-->C (Leu69Pro) sequence change in exon 4 in one patient, which is predicted here to disrupt the beta -sheet structure in CRYBA4. Protein folding would consequently be impaired, most probably leading to a structure with reduced stability in the mutant. This is the first report linking mutations in CRYBA4 to cataractogenesis and microphthalmia.

Identification of novel mutant PAX6 alleles in Indian cases of familial aniridia.

BACKGROUND: Haploinsufficiency at the PAX6 locus causes aniridia, a panocular eye condition characterized by iris hypoplasia and a variety of other anterior and posterior eye defects leading to poor vision. This study was performed to identify novel PAX6 mutations that lead to familial aniridia in Indian patients. METHODS: Genomic DNA was isolated from affected individuals (clinically diagnosed aniridia) from nine unrelated aniridic pedigrees, unaffected family members, and unrelated normal controls. The coding regions of PAX6 were amplified and subjected to single strand conformation polymorphism (SSCP) gel analysis, and direct cloning and sequencing. RESULTS: SSCP band shifts, indicative of DNA base pair mutations, were observed in five of these unrelated families. Four mutations were shown to be previously unreported insertion or deletions in PAX6, leading to frameshifts. These new mutations were c.1174delTG (in exon 10), c.710delC (exon 6), c.406delTT (exon 5) and c.393insTCAGC (exon 5). The other nonsense mutation, a transition (c.1080C>T) in exon 9, has been reported previously as a mutation hotspot for PAX6 in other ethnic pedigrees. All mutant alleles transmitted through aniridic individuals in each family. CONCLUSION: These new deletions and an insertion create frameshifts, which are predicted to introduce premature termination codons into the PAX6 reading frame. The genetic alterations carried by affected individuals are predicted to lead to loss-of-function mutations that would segregate in an autosomal dominant manner to subsequent generations. This is the first report of the 'hotspot' c.1080C>T transition from Indian families.

PAX6 missense mutations associated in patients with optic nerve malformation.

PURPOSE: PAX6 missense mutations are likely to cause a spectrum of ocular, neurological, and systemic developmental defects and have been reported in various ethnic groups. The purpose of this study was to investigate the clinical features of optic nerve malformation caused by PAX6 mutations in Indian patients. METHODS: Total genomic DNA was isolated from peripheral blood of 27 sporadic probands affected with congenital optic nerve malformation, unaffected family members, and 50 unrelated age-matched controls. Informed consent was obtained from all study subjects. Polymerase chain reaction was carried out to explore PAX6 defective alleles using single-strand conformation analysis (PCR-SSCA) followed by automated bidirectional sequencing. RESULTS: We identified two novel PAX6 missense mutations in two unrelated sporadic probands. The mutation analysis revealed variation at position c.469G>C, codon 36 in proband ONH 4-1 with optic nerve hypoplasia. The other de novo mutation was observed at c.514G>C, codon 51 in proband ODC 5-1 with optic disc coloboma. Both G>C base substitutions cause a relatively conservative amino acid change, altering glycine to alanine residues within the paired DNA-binding domain. CONCLUSIONS: In this study, we have been able to identify two sequence variations in the PAX6 gene. These missense mutations may uniquely alter the structure and expression of PAX6 protein, resulting in distinct clinical phenotypes. Mutation analysis of 27 probands for PAX6 has resulted in only two significant variants. This finding demonstrated that the frequency of PAX6 mutations associated with optic nerve malformation is low, requiring the elucidation of other candidate genes in other patients.

Novel mutations in GJA8 associated with autosomal dominant congenital cataract and microcornea.

PURPOSE: The purpose of this study was to estimate the importance of mutations in the connexin50 gene (GJA8) as a cause of congenital or developmental cataracts in the Indian population and to identify novel mutations in GJA8 that cause cataract in this population. METHODS: The coding region of GJA8 was analyzed for mutation by single strand conformational polymorphism in 60 probands affected with congenital or developmental cataract of which 11 probands' corneal diameter measured less than 11.00 mm. Direct sequencing was performed for samples that displayed an abnormal electrophoresis pattern. The segregation of the change with the diseased phenotype was analyzed in the entire pedigree by restriction fragment length polymorphism (RFLP) analysis. RESULTS: Molecular analysis of GJA8 revealed two novel missense mutations V44E and R198Q, in the population screened. The mutations cosegregated with the diseased phenotype in an autosomal dominant manner and were absent in 400 normal control chromosomes analyzed. GJA8 mutations were seen in two of the 60 unrelated probands with cataracts. Affected individuals in both of whose families also had microcornea and variable myopia. CONCLUSIONS: This is the first report of mutations in GJA8 to be associated with autosomal dominant cataract and microcornea. Mutations in GJA8 cause 3.3% of congenital cataracts in the population of India.