Ectopia lentis et pupillae

A novel missense variant expands the phenotype and genotype of PAX6-associated foveal hypoplasia accompanied by various manifestations of anterior segment dysgenesis

BACKGROUND

According to previous reports, PAX6-associated foveal hypoplasia (FH) could usually be accompanied by various anterior segment anomalies including variable iris changes. This study aims to exhibit unusual phenotypes of a novel missense variant of PAX6 from a Chinese pedigree.

METHODS

Ophthalmic examinations including slit-lamp biomicroscopy, gonioscopy, ophthalmic ultrasound, ultrasonic biomicroscopy, optical coherence tomography, wide-field fundus imaging, and visual field test were performed to evaluate the clinical manifestations. Whole-exome sequencing (WES) and bioinformatics analysis were conducted in eight members from this pedigree to identify the causative mutation.

RESULTS

WES revealed a novel heterozygous substitution of PAX6 (NM_000280.5:c.157G > A, p.(Val53Met) (chr11:31823309 C > T, hg19)), which cosegregated with the phenotype of this pedigree. All the three patients (a pair of fraternal twins and their mother) exhibited bilateral FH and anterior segment dysgenesis (ASD) including microcornea, sclerocornea, obvious symmetrical corectopia, iris stromal dysplasia, goniodysgenesis, and abnormal distribution of fundus blood vessels. The girl of the fraternal twins also demonstrated bilateral temporal deviation of lenses and abnormal tissue membrane connecting anterior chamber angle and lens anterior capsule in the right eye. The mother additionally showed apparent cataract bilaterally and cupping of the optic disc in her left eye.

CONCLUSION

A novel missense variant in PAX6 gene was detected in a Chinese pedigree demonstrating bilateral FH and ASD. It is really distinctive that the ASD involves almost all parts of the anterior segment, and bilateral symmetrical corectopia is the most perceptible sign. This study expands the phenotypic and genotypic spectrum of PAX6-associated ocular diseases, and facilitates the understanding of the crucial role that PAX6 plays in the development of the eye. Meanwhile, PAX6 could be considered as a candidate pathogenic gene of bilateral symmetrical corectopia.

Congenital ocular malformations (lens subluxation, pupillary displacement, cataract, myopia) and classic galactosaemia associated with Q188R and /or G1391A mutations

PURPOSE

Observations of multiple ocular malformations together with heterozygosity for galactosaemia in siblings and homozygosity in one child are highly unusual. In these case histories, a series of investigations in one family are reported.

METHODS

Members of a family of two brothers and one sister and their children were pre- and post-surgically examined over several years. Blood examination was carried out in a laboratory specializing in investigation into genetic diseases (Dr Podskarbi, Munich).

RESULTS

Two brothers and one sister suffered from cataract-induced visual deterioration at 38, 34 and 35 years of age, respectively. All three siblings reported having had bilateral poor vision since early childhood. The three siblings' parents had no congenital ocular malformations, nor was there any parental consanguinity. One child, the 10-year-old son of the 35-year-old sister, exhibited classic galactosaemia and normal ocular findings. This sister's other child was healthy. All three siblings presented congenital lens luxation, axial myopia, cataract and iridodonesis. In addition, the 34-year-old brother showed unilateral right corectopia and left coloboma adjacent to the optic disc. The 38-year-old brother revealed myopic fundus changes, but no coloboma. The three siblings experienced a distinct increase in visual acuity after cataract surgery. Both eyes of the patients were partially or distinctly amblyopic, respectively. We assume an autosomal-recessive transmission. Molecular genetic examination of the 10-year-old child with classic galactosaemia showed homozygosity for the mutation Q188R with a complete galactose-1-phosphate-uridyltransferase (GALT) deficiency. Because of his galactose-free diet, the child showed normal values for galactose-1-phosphate. The 35-year-old mother showed compound heterozygosity for Q188R and G1391A (D2/G). The 10-year-old boy's father also revealed heterozygosity for galactosaemia caused by GALT deficiency. The two children of the 38-year-old brother were heterozygous for G1391A. They did not show any clinical abnormality. None of the family members had clinical signs of Marfan's syndrome or homocysteinuria. The three siblings' parents were not consanguineous.

CONCLUSIONS

Patients with worsening cataracts occurring at a pre-senile age should be examined for galactosaemia. We describe for the first time the molecular genetic findings in congenital ectopia lentis et pupillae. Early treatment in conjunction with a galactose-free diet is mandatory in patients with galactosaemia. Members of a family with heterozygosity for galactosaemia should be advised to attend a human genetic consultation.

Ectopia lentis et pupillae: report of a unilateral case and surgical management

PURPOSE

To report a case of clinically unilateral congenital ectopia lentis et pupillae (ELeP) and discuss its surgical management.

DESIGN

Interventional case report.

METHODS AND RESULTS

A 37-year-old female was referred to our service for surgical management of unilateral ectopia pupillae for aesthetic reasons. On presentation the visual acuity of the affected eye was 20/400. Ultrasound exam did not show any crystalline lens dislocation, and therefore the case was considered a very rare variable of the ELeP syndrome. We proceeded to surgical correction of the pupillary ectopia. At the 3-month follow-up the patient's visual acuity was 20/30.

CONCLUSIONS

Although the clinical features and the genetic aspects of ELeP are documented in the older ophthalmic literature, this entity has received relatively little attention. Surgical correction of this rare disorder can be attempted for aesthetic and functional reasons.

Vitrectomy for phacolytic glaucoma in a patient with ectopia lentis et pupillae

This case report highlights the successful management, by vitrectomy alone, of a case of chronic phacolytic glaucoma secondary to a dislocated hypermature lens in the vitreous of a patient with ectopia lentis et pupillae (ELP). The features and complications of ELP are discussed.

Ectopia lentis et pupillae. A hypothesis revisited

BACKGROUND

Ectopia lentis et pupillae (ELeP) is a rare congenital inherited disorder characterized by lenticular and pupillary ectopia. Recent speculation on its pathogenesis is based on clinical observation and includes a neuroectodermal defect or persistence of fetal vasculature. None of these reports included histopathology or imaging studies.

STUDY DESIGN

Case report and literature review.

INTERVENTION

The authors examined a 55-year-old woman with ELeP using 10-MHz and 50-MHz ultrasonography to demonstrate the structural abnormalities present. Five patients (eight eyes) who had undergone cataract extraction without lens implantation were also examined.

RESULTS

In the patient with ELeP, the right pupil was displaced inferiorly and the left temporally. An ultrasound scan at 10 MHz showed both lenses lying inferiorly in the vitreous. An ultrasound scan at 50 MHz allowed detailed examination of the anterior segment, including the iris and ciliary body, and showed two main features in each eye, including a lack of definition of ciliary processes, except in that quadrant toward which the pupil was displaced, and a membrane-like structure extending forward and attaching to the proximal pupil margin. The membrane passed over the tips of the ciliary processes to a more posterior origin.

CONCLUSIONS

The only histologic reports of this condition are from the beginning of this century in the German literature. Ultrasonography at 50 MHz allows high-resolution in vivo imaging of anterior structures that are not clinically visible. The authors' findings in this case of ELeP are sufficiently different from those of non-ELeP-related aphakia to suggest that they are not solely due to aphakia. Furthermore, the authors' findings are very similar to the only histologic reports suggesting that the pupillary and lenticular ectopia results from mechanical tethering of the pupil with zonular disruption. This hypothesis has not been discussed in the recent literature.

Ectopia lentis et pupillae syndrome in three generations

In nine members from three generations and in a distant relative, at least three significant characteristics of the ectopia lentis et pupillae syndrome were established including ectopia lentis, ectopia pupillae, persistent pupillary membrane, iris transillumination, and poor pupillary dilatation. All patients developed bilateral cataract before the age of 40 years, and two patients presented with intermittent acute intraocular hypertensive crises. Not only the high number of patients in one family, but also the occurrence in three generations is very exceptional for the ectopia lentis et pupillae syndrome. Although the syndrome is said to be inherited in an autosomal recessive mode, in this family, a mother to son and a mother to daughter transmission were present. Pedigree analysis yielded arguments in favour of an autosomal dominant inheritance with reduced penetrance. A biochemical correlation was not identified.

Lens-induced glaucoma

The crystalline lens is implicated as a causative element in producing several forms of glaucoma. Etiologically they represent a diversity in the presentation of the glaucomatous process. These conditions include glaucoma related to: lens dislocation (ectopia lentis), lens swelling (intumescent cataract), classical pupillary block, aqueous misdirection--ciliary block, phacoanaphylaxis, lens particle, and phacolytic glaucoma. The management of elevated intraocular pressure often requires altering the intraocular relationship of anatomic structures surrounding the lens or lens removal. We will review the entities that produce these lens-induced glaucomatous conditions and suggest a rational approach to their diagnosis and treatment.

Autosomal recessive ectopia lentis in two Arab family pedigrees

Nineteen patients with bilateral ectopia lentis and no other ocular abnormalities in two Arab families are described. The two family pedigrees demonstrate an autosomal recessive inheritance in contrast to the majority of reported family pedigrees with this condition which show dominant inheritance. The early onset of the condition, its natural course and its consequences on visual function are described.

Clinical manifestations of ectopia lentis et pupillae in 16 patients

The largest known series of patients with ectopia lentis et pupillae (ELeP) was clinically evaluated. Sixteen patients from eight families were characterized with respect to ocular anomalies. Variability between eyes of the same patient and among different patients was marked. In addition to the well-known but inconstant displacement of the lens and pupil, other characteristics of this protean syndrome included severe axial myopia (and associated fundus abnormalities), poor vision, retinal detachment (RD), enlarged corneal diameters, cataract, abnormal iris transillumination, poor pupillary dilatation, persistent pupillary membranes, iridohyaloid adhesions, and prominent iris processes in the anterior chamber angle.

Selected eye defects of special importance in pediatrics

This article reviews six defects of special importance in the care of children: aniridia, ectopia lentis, cataracts, glaucoma, colobomata, and optic nerve hypoplasia. In addition to causing potentially serious impairment of vision, these ocular disorders may be associated with significant systemic disease and genetic abnormalities.

Familial simple ectopia lentis. A probable autosomal recessive form

All three sibs from normal and unrelated parents had congenital ectopia lentis without extraocular abnormalities. This pedigree suggests an autosomal recessive form of simple ectopia lentis.

Corectopia with nystagmus, absent foveal reflexes and corneal changes

A family is described with corectopia, nystagmus, absent foveal reflexes, and corneal changes inherited in an autosomal dominant pattern. Other abnormalities found in this family include microcornea, Bitot's spots, and iris colobomas. Faint superficial opacities and fine superficial vessels were found in the peripheral cornea of younger family members. Older family members showed an increase in the density of the superficial opacities and areas of stromal thinning were found in the 60-year-old proband. Corneal vessels and progression centrally. Full-thickness stromal opacities and changes have been associated with familial and sporadic aniridia and iris colobomas. The present report describes similar changes in association with corectopia.

Isolated congenital ectopia lentis with autosomal dominant inheritance

Although autosomal dominant inheritance of isolated ectopia lentis has been described, the literature contains old and unclear reports concerning the evaluation of skeletal or metabolic abnormalities. We report a family in which congenital isolated ectopia lentis occurs in five members of two generations in a pattern consistent with autosomal dominant inheritance.