Ectopic lens material in an otherwise healthy 5-week-old infant.

PURPOSE: To report the unusual finding of ectopic lens material in an otherwise healthy 5-week-old infant. METHODS: Case report and literature review. RESULTS: An asymptomatic 5-week-old female infant was found to have unilateral ectopic lens material in the retrolental space of the left eye associated with a posterior capsular defect. CONCLUSION: The abnormality is likely embryological in origin, and the established progression for similar conditions means long-term monitoring is required to ensure the best possible visual outcome.

Jellyfish sign for intraoperative identification of posterior lenticonus.

Posterior lenticonus is a rare progressive disease characterized by protrusion of posterior lens capsule along with lens cortex into the vitreous cavity. It may be associated with local thinning or absence of posterior lens capsule. It generally occurs sporadically, but familial cases have also been reported. If visually significant or if amblyopia is present, lens removal is indicated. Treatment consists of clear or cataractous lens extraction, optical correction along with prompt amblyopia therapy. In this case, we propose a "jellyfish sign" seen intraoperatively, which is referred to the characteristic movement of the posterior capsular cataractous material on injection of balanced salt solution in the capsular bag.

Bilateral Congenital Posterior Capsular Defects and Ectopic Cataracts.

Preexisting posterior capsular defects are rare and can be associated with infantile cataracts. The authors review possible etiologies of this condition and emphasize the importance of cautious preoperative planning and surgery.

Lenticonus diagnosis in Alport's syndrome: Anterior capsule apical angle calculation using Scheimpflug imagery.

OBJECTIVE: We describe a simplified method to detect anterior lenticonus. Three eyes of 2 patients with anterior lenticonus, plus 16 eyes from 16 healthy controls underwent Scheimpflug imaging of their anterior segment with Pentacam. The anterior capsule apex angle was manually identified and automatically measured by AutoCAD. RESULTS: The mean angle was 173.06° (SD: 1.91) in healthy subjects, and 158.33° (SD: 3.05) in anterior lenticonus eyes. The angle obtained from patients was more than 3 SD steeper than those from healthy subjects. CONCLUSIONS: The apical angle calculation method seems to discriminate well between normal eyes and eyes suspected of having anterior lenticonus.

Rac1 GTPase-deficient mouse lens exhibits defects in shape, suture formation, fiber cell migration and survival.

Morphogenesis and shape of the ocular lens depend on epithelial cell elongation and differentiation into fiber cells, followed by the symmetric and compact organization of fiber cells within an enclosed extracellular matrix-enriched elastic capsule. The cellular mechanisms orchestrating these different events however, remain obscure. We investigated the role of the Rac1 GTPase in these processes by targeted deletion of expression using the conditional gene knockout (cKO) approach. Rac1 cKO mice were derived from two different Cre (Le-Cre and MLR-10) transgenic mice in which lens-specific Cre expression starts at embryonic day 8.75 and 10.5, respectively, in both the lens epithelium and fiber cells. The Le-Cre/Rac1 cKO mice exhibited an early-onset (E12.5) and severe lens phenotype compared to the MLR-10/Rac1 cKO (E15.5) mice. While the Le-Cre/Rac1 cKO lenses displayed delayed primary fiber cell elongation, lenses from both Rac1 cKO strains were characterized by abnormal shape, impaired secondary fiber cell migration, sutural defects and thinning of the posterior capsule which often led to rupture. Lens fiber cell N-cadherin/ß-catenin/Rap1/Nectin-based cell-cell junction formation and WAVE-2/Abi-2/Nap1-regulated actin polymerization were impaired in the Rac1 deficient mice. Additionally, the Rac1 cKO lenses were characterized by a shortened epithelial sheet, reduced levels of extracellular matrix (ECM) proteins and increased apoptosis. Taken together, these data uncover the essential role of Rac1 GTPase activity in establishment and maintenance of lens shape, suture formation and capsule integrity, and in fiber cell migration, adhesion and survival, via regulation of actin cytoskeletal dynamics, cell adhesive interactions and ECM turnover.

Cataract surgery in a patient with unilateral cataracta membranacea.

Cataracta membranacea (CM) is a rare condition characterized by the remnants of lens capsules and fibrous proliferation that develops secondary to lens matter liquefaction and absorption. Although CM is usually bilateral and may be associated with other congenital anomalies and poor visual prognosis; it can rarely be seen in the adults with involvement of only one eye. Reported herein, is a case of 57-year-old man who presented with CM in his right eye and underwent successful in-the-bag intraocular lens implantation with good visual outcome.

Congenital pupillary-iris-lens membrane with goniodysgenesis: histopathologic findings in an enucleated eye.

A 10-year-old boy with clinically confirmed congenital pupillary-iris-lens membrane with goniodysgenesis underwent light microscopic examination of the enucleated eye. The anterior segment changes consisted of the absence of the iridial pupillary sphincter muscle and dilator muscle processes. Endothelialization and descemetization of the anterior chamber angle and the anterior surface of the iris covered the original eccentric pupillary opening (occlusio pupillae), but grew around the fibrotic edges of the surgically created, patent pseudopupil, probably secondary responses to surgery. The anterior chamber findings in this case establish a localized syndrome that includes absence of the pupillary sphincter and dilator muscle processes. Incomplete development of the iris may be partly attributable to an abnormality of stromal development and inductions by the anterior neuroectodermal layer, together with anomalies of the pupillo-iridial vasculature.

Progression of a unilateral posterior lentiglobus associated with a persistent fetal vasculature stalk.

An 8-month-old boy was found to have unilateral persistent fetal vasculature (PFV) and a small visually insignificant lens opacity. No changes were noted in the appearance of the eye on examinations up to age 3 years. At the age of 4 years, a posterior lentiglobus requiring surgical intervention developed. The thinned and bulging posterior capsule ruptured at surgery. PFV, when treated conservatively, has not been reported to lead to progressive lentiglobus. This case documents the rare concurrence of PFV and lentiglobus.

Preexisting posterior capsule defect progressing to white mature cataract.

We present two children discovered to have a total cataract in one eye with a posterior subcapsular cataract in the other eye. Sequential photography documented rapid progression of the posterior subcapsular cataract to a preexisting posterior capsule defect and subsequently to a white, mature cataract. We propose that early intervention be considered in cases with any posterior subcapsular changes (no matter how subtle) and history of total cataract in the fellow eye, especially in any situation where loss of follow-up is likely to occur. In the event surgery is not advised, parents should be warned about possible cataract progression and the importance of regular follow-up examinations.

[Clinical pathological study of the anterior lens capsule abnormalities in familial congenital aniridia with cataract].

OBJECTIVE: To observe the pathological changes of the lens and anterior lens capsule of the patients with familial congenital aniridia, and discuss the histopathological etiology of the fragility of the anterior capsule and the significance of surgical project. METHODS: Anterior lens capsules and lens specimens were obtained from aniridic patients during cataract surgery. The intraoperative behavior of each capsule was noted, after which the specimens were submitted for histopathologic evaluation and electron microscope examination. RESULTS: The anterior lens capsule was extremely fragile and remarkably thin. Degenerative changes(degeneration, necrosis, loss) of the lens epithelium and discontinuity of the lens epithelium were found in some specimens. Proliferation and double layer of the epithelial cells in some area of the specimens can be seen also. Ply structure of the anterior capsule became thin or disappeared. CONCLUSION: Degenerative or proliferative changes of the lens epithelial cells were associated with the thinness and extreme intraperative fragility of the anterior lens capsules in familial aniridia with cataract. Greater awareness of anterior capsule fragility in some aniridic patients with cataract may reduce the risk of capsule complications and lead to safer surgical outcomes.

Severe defects in proliferation and differentiation of lens cells in Foxe3 null mice.

During mouse eye development, the correct formation of the lens occurs as a result of reciprocal interactions between the neuroectoderm that forms the retina and surface ectoderm that forms the lens. Although many transcription factors required for early lens development have been identified, the mechanism and genetic interactions mediated by them remain poorly understood. Foxe3 encodes a winged helix-forkhead transcription factor that is initially expressed in the developing brain and in the lens placode and later restricted exclusively to the anterior lens epithelium. Here, we show that targeted disruption of Foxe3 results in abnormal development of the eye. Cells of the anterior lens epithelium show a decreased rate of proliferation, resulting in a smaller than normal lens. The anterior lens epithelium does not properly separate from the cornea and frequently forms an unusual, multilayered tissue. Because of the abnormal differentiation, lens fiber cells do not form properly, and the morphogenesis of the lens is greatly affected. The abnormally differentiated lens cells remain irregular in shape, and the lens becomes vacuolated. The defects in lens development correlate with changes in the expression of growth and differentiation factor genes, including DNase II-like acid DNase, Prox1, p57, and PDGFalpha receptor. As a result of abnormal lens development, the cornea and the retina are also affected. While Foxe3 is also expressed in a distinct region of the embryonic brain, we have not observed abnormal development of the brain in Foxe3(-/-) animals.

Diagnosis and management of congenital cataract with preexisting posterior capsule defect.

PURPOSE: To establish and evaluate the diagnostic signs, intraoperative performance, and postoperative outcomes in children with congenital cataract with a preexisting posterior capsule defect (PCD). SETTING: Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS: This study evaluated 400 consecutive eyes that had congenital cataract surgery, of which 27 (20 children) had a confirmed preexisting PCD. Seven children had bilateral defects. The preoperative diagnostic signs of PCD under maximum pupil dilation included well-demarcated, thick defect margins; white dots on the posterior capsule; and white dots in the anterior vitreous that moved with the degenerated vitreous like a fish tail (fish-tail sign). Hydrodissection was not attempted. Bimanual irrigation/aspiration and 2-port anterior vitrectomy were performed. The mean follow-up was 17.9 months +/- 16.96 (SD). RESULTS: The mean age of the 16 boys and 4 girls with a PCD was 21.98 +/- 33.33 months. Nineteen eyes (70.3%) had total white mature cataract. In 7 eyes (25.92%), the preexisting PCD was converted into a posterior capsulorhexis. Twenty eyes (74.07%) had an AcrySof MA30BA intraocular lens (IOL) implanted in the bag and 4 eyes (14.81%), in the sulcus. Three eyes (11.11%) were left aphakic. The visual axis remained clear in all eyes, and the IOL was well centered in 24 eyes (88.88%). CONCLUSION: Establishing the diagnostic signs of PCD with the eye fully dilated and carefully planning the surgery produced satisfactory technical and visual outcomes.

Iridoschisis and bilateral lens subluxation associated with periocular eczema.

We present a 53-year-old man with bilateral lens subluxation, unilateral iridoschisis, and a long-standing history of periocular eczema. Although a case of unilateral lens subluxation and ipsilateral iridoschisis has been described recently, the pathogenesis of this simultaneous occurrence remains unclear. Our case raises questions about the relationship among these clinical observations and suggests that these findings may exist as part of an unrecognized oculodermal syndrome.

High exogenous homocysteine modifies eye development in early chick embryos.

BACKGROUND: Homocysteine is a nonessential aminoacid whose increase is related to the appearance of neural tube defects in humans. In chick embryos, high levels of homocysteine produce neural tube defects and alteration of neural crest cell migration. METHODS: In our study, 8 microl of L-homocysteine thiolatone (20 micromol) was added to chick embryos of Stages 3-8/10 (Hamburger and Hamilton, 1951), (1238 hr of incubation). Three days later, 50 embryos, externally normal or carrying isolated spinal neural tube defects, were sectioned and stained by hematoxilin-eosin or anti-fibrillin-1 antibody. RESULTS: The eye showed alterations of the optic cup as microphthalmia, or lens dislocation. In both cases, the incidence of alterations diminished with the age of the homocysteine-increased embryos. Optic cup modifications are probably associated with central nervous system alterations, because most of the affected embryos exhibited isolated spinal neural tube defects and had altered neural crest cells. We have shown for the first time that high exogenous homocysteine during early development could produce a caudally-displaced lens axis before the zonule is formed. Fibrillin-1 is the main component of elastic microfibrils, and in the adult human it is seen as a protein particularly susceptible to homocysteine attack. CONCLUSIONS: Antibody staining against fibrillin-1 showed no evident morphological differences in distribution between experimental and control embryos in the lens, suggesting that fibrillin-1 was not the cause, and malformations may be attributed to other mechanisms.

Evaluation of lenticonus in Alport's syndrome: quantitative Scheimpflug analysis.

Anterior lenticonus is an ocular abnormality that can occur in Alport's syndrome. In this study, Scheimpflug slit imaging analyses were employed for quantitative and objective evaluation of lens changes associated with Alport's syndrome. It was determined that while the apices of the lenticular protrusions are central in the vertical plane, they are nasally displaced in the horizontal meridian. The eccentricity and dimensions of the diameters and thicknesses of the conical aberration are highly correlated in both eyes. Lens thickness and anterior chamber depth do not differ between eyes. Densitometrically similar differences are apparent in the cortex and nuclear regions although evidence of overt opacification may or may not be present. The data strongly suggest that the physical parameters of the lenticonus are consistent with the constraints imposed by the pupil. Changes observed in the cornea and the vitreous may be associated with the syndrome.

Alterations in the lens capsule contribute to cataractogenesis in SPARC-null mice.

The lens capsule, which is also called the lens basement membrane, is a specialized extracellular matrix produced anteriorly by the lens epithelium and posteriorly by newly differentiated fiber cells. SPARC (secreted protein, acidic and rich in cysteine) is a matricellular glycoprotein that regulates cell-cell and cell-matrix interactions, cellular proliferation and differentiation, and the expression of genes encoding extracellular matrix components. SPARC-null mice exhibit lens opacity 1 month after birth and mature cataract and capsular rupture at 5-7 months. In this study, we report disruption of the structural integrity of the lens capsule in mice lacking SPARC. The major structural protein of basement membrane, collagen type IV, in the lens capsule was substantially altered in the absence of SPARC. The lens cells immediately beneath the capsule showed aberrant morphology, with numerous protrusions into the lens basement membrane. SPARC-null lenses at 1 month of age exhibited an increased penetration of dye or radioactive tracer through the capsule, as well as a higher content of water than their wild-type counterparts. Moreover, SPARC-null fibers exhibited swelling as early as 1 month of age; by 3 months, all the fiber cells appeared swollen to a marked degree. By contrast, the absence of SPARC had no apparent morphological effect on the early stages of lens formation, cell proliferation or fiber cell differentiation. Degradation of crystallins and MIP 26, or changes in the levels of these proteins, were not detected. These results underscore the importance of the capsular extracellular matrix in the maintenance of lens transparency and indicate that SPARC participates in the synthesis, assembly and/or stabilization of the lens basement membrane.

Oval-shaped cornea, lens duplication, and optic nerve hypoplasia associated with myelomeningocele.

Oval-shaped cornea associated with true lens duplication and separate capsules is a rare anomaly. It can occur as an isolated finding(1,2) or be associated with other ocular and facial maldevelopments.(3-5) We report a novel association of an hourglass cornea, lens duplication, and optic nerve hypoplasia with myelomeningocele in a male infant.

Lenticonus.

Lenticonus is a bulging of the lens capsule and the underlying cortex. The diagnosis of lenticonus is essentially a clinical diagnosis which is made by biomicroscopic examination. According to the localization of the conus a distinction is made between lenticonus anterior and lenticonus posterior. Whereas lenticonus anterior is part of the Alport syndrome, lenticonus posterior is not associated with systemic disease. A case report of each of both types is presented and the clinical presentation, the aetiology, the pathogenesis and the treatment are discussed.

[Excentric lentiglobus posterior]. / Exzentrischer Lentiglobus posterior.

BACKGROUND: The posterior lentiglobe is a rare anomaly of the lens shape. Two cases of excentric protuberance of the posterior capsule are presented. To our knowledge, only one description of a similar case exists so far. PATIENTS: An eight-year-old girl (diagnosis by routine examination, V.A. 20/20) and a six-year-old boy (V. A. 20/200, esotropia) are presented. Apart from a persistent hyperplastic primary vitreous and a posterior pole cataract a vitreous cyst adherent to the posterior surface of the lens has to be considered as differential diagnosis. The etiology remains unclear. CONCLUSION: In excentric posterior lengtiglobe a good vision is possible. However, if visual acuity is impaired by posterior pole opacity or distortion of the spherical surface, removal of the lens followed by optical correction (contact lens, intraocular lens) of aphakia should be performed.