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At least 667 records · Page 37Linked to original sources
PubMed1985

Ocular findings in the facioauriculovertebral sequence (Goldenhar-Gorlin syndrome).

We reviewed the ocular findings in 57 consecutive patients with the facioauriculovertebral sequence (Goldenhar-Gorlin syndrome). Epibulbar choristomas were detected in 18 cases (32%), a much lower occurrence than reported previously. Various motility disorders (11 cases, 19%), blepharoptosis or narrow palpebral fissures (seven cases, 12%), eyelid colobomas (six cases, 11%), and lacrimal drainage system anomalies (six cases, 11%) were more frequent than previously noted. These ocular findings were more common in the patients with epibulbar choristomas. Of the various features of the Goldenhar-Gorlin syndrome (skin tags, microtia, hemifacial microsomia, and vertebral anomalies), only skin tags correlated positively with the laterality of epibulbar choristomas. Preauricular and facial tags represent choristomas, explaining their association with epibulbar choristomas and the laterality they share.

Abnormalities, Multiple↗
PubMed1987

Corneal transplantation in microphthalmic eyes.

We performed corneal transplantation in nine microphthalmic eyes of five patients, who ranged in age from 1 to 63 months. The anteroposterior diameter of the eyes ranged from 12.5 to 16 mm. Complications from the surgery included superficial epithelial erosions in three eyes, leading to superficial scarring in one eye, glaucoma, and suture microabscesses. Despite these complications, seven of nine grafts have remained clear and vision developed in all eyes.

Abscess↗
PubMed1994

Dental abnormalities in the osteopetrotic rat mutation microphthalmia blanc.

Dental manifestations of the mild, transient osteopetrosis in the rat mutation microphthalmia blanc (mib) were examined. Eruption of all teeth was delayed in mib rats compared to normal littermates. The delays ranged from 5 days for incisors to 3 and 2 days for the first and second molars. Normal rats had straight incisors in the sagittal plane that exhibited signs of wear, but in mib littermates the incisors were maloccluded, distorted, and showed no signs of wear. Radiographic and histological examination of the dentition of 1- and 4-week-old rats revealed that the apical end of incisors in mib rats failed to extend posteriorly to the third molar region as in normal siblings, but ended at the first molar. Histological examination of longitudinal sections of mandibles through the incisors of neonatal normal and mib rats showed that in 1-day-old mutants the incisor was closely surrounded by alveolar bone to which it was ankylosed. The incisor body in mib rats was also malformed, with an indented apical end. This ankylosis was temporary, being resolved by 3 days. These findings show that neonatal reductions in bone resorption cause incisor defects and delay the eruption of all teeth in mib rats. The malocclusion and distortion of incisors of mib rats are likely caused by temporary ankylosis of incisor matrices to alveolar bone. Taken together, these findings illustrate the concept that bone resorption is an essential and rate-limiting element of tooth eruption.

Animals↗
PubMed1991

Defect of a fiber cell-specific 94-kDa protein in the lens of inherited microphthalmic mutant mouse Elo.

Deficiency in a 94,000-dalton protein in the non-crystallin fraction from the Elo mouse lens was shown. To perform further investigations, we raised an antibody against the 94,000-dalton protein isolated from normal mouse lens. Western blot analysis with the antibody indicated that the protein was only present in the lens and not in the brain, lung, heart, liver, and kidney. In the lens, it was unique to the cortex and nucleus fractions, not being present in the epithelial cells. Furthermore, it was observed in the water-soluble fraction as well as in the urea-soluble fraction. The antibody weakly but clearly reacted with the chick CP97 lens peptide, a fiber cell-specific protein, and anti-CP97 antibody also reacted with the 94,000-dalton protein. From these results, we concluded that the protein corresponds to CP97 cytoskeletal protein in the mouse lens. The protein was deficient in the lenses from Elo mice, but microphthalmic lenses from CTA mice contained a normal level.

Animals↗
PubMed1991

Developmental analysis of ocular morphogenesis in alpha A-crystallin/diphtheria toxin transgenic mice undergoing ablation of the lens.

The role of the lens in early eye development was examined in transgenic mice carrying the cytotoxic diphtheria toxin A gene driven by hamster alpha A-crystallin promoter sequences. Mice hemizygous for this construct are microphthalmic and contain a vacuolated and highly disorganized lens, whereas adult homozygous mice are completely ablated of the lens and lack a pupil, aqueous and posterior chamber, vitreous humor, iris, and ciliary body and show extensive convolution of the sensory retina. Developmental analysis of animals homozygous for the transgene revealed that the optic cup and lens vesicle form normally and that ablation of the lens occurs as a gradual degenerative process beginning between Days 12 and 13 of gestation. Degeneration of the lens vesicle coincides with retarded growth and development of the neuroretina, sclera, and cornea. The anterior lip of the optic cup fails to differentiate into the normal epithelium of the iris and ciliary body and the vitreous body does not develop. Although the retinal layers apparently form normally, retinal folding becomes prominent following lens degeneration. These results suggest that development of a functional lens from Embryonic Day 12.5 onward is critical for formation of the ciliary epithelium, iris, and vitreous body, as well as for appropriate growth, development, and maintenance of morphology of the retina, cornea, sclera, and optic nerve. Our results also provide information on the time course of DT-A-mediated cell destruction in vivo and are discussed in context with previous lens ablation studies and the importance of developmental analysis for interpretation of the extent to which morphogenetic aberrations are concurrent with or secondary to genetic ablation of the target tissue.

Animals↗
PubMed1992

Transgenic mice expressing a constitutively active retinoic acid receptor in the lens exhibit ocular defects.

Retinoic acid receptors (RARs) modulate gene expression following association with retinoic acid (RA). In transient transfection, an RAR alpha-beta-galactosidase fusion protein (RAR-LacZ) was able to transactivate expression in the absence of RA. When expressed in the ocular lens of transgenic mice, this constitutively active RAR-LacZ fusion gene resulted in founder and progeny animals that exhibited cataracts and microphthalmia, both being characteristics of retinoid-induced teratogenesis. The transgenic phenotypes indicate that retinoid teratogenesis can be mimicked by expression of a constitutively active RAR-LacZ fusion protein in retinoid-sensitive tissues.

Animals↗
PubMed1984

Development and aging of the eye in mice with inherited optic nerve aplasia: histopathological studies.

We have examined the morphological development of optic nerve aplasia in a subpopulation (10-20%) of anophthalmic mice (Strain ZRDCT -AN) that develop microphthalmia. During embryonic stages the optic fissure in microphthalmic mutants did not involute into the optic stalk. Even in the absence of a proper fissure, early differentiation of the various retinal elements was not disturbed. Subsequently, however, the optic nerve fibers failed to exit from the eye in their appropriate position. Secondary changes in the retina, probably resulting from a failure of optic axons to reach their central targets, were near total loss of ganglion cells and variable attenuation of the other nuclear and plexiform layers. Retinal rosettes were also commonly present.

Age Factors↗
PubMed1989

The optic fissure in the normal and microphthalmic mouse.

The gene for microphthalmia in the homozygous cinnamon mouse produces colobomatous microphthalmia due to failure of closure of the optic fissure. Optic fissure formation and closure were examined in control cinnamon and homozygous microphthalmic foetuses from the 10th to the 13th gestational day using light and electron microscopy. This study showed that basal lamina degeneration and cell death occurred in the area of fusion in the control eyes. Examination of the optic fissure in homozygous microphthalmic foetuses showed cell death in the fissure margins, but there was failure of optic fissure closure associated with persistence of the basal lamina. It is therefore suggested that absence or abnormality of programmed disintegration of the basal lamina prevents fusion in the mutant leading to the development of colobomatous microphthalmia.

Animals↗
PubMed1983

Quantitative analysis of the lateral geniculate nucleus in the mutant microphthalmic rat.

A quantitative analysis of the lateral geniculate nucleus was carried out in the mutant microphthalmic rat. In the dorsal lateral geniculate nucleus (LGNd) of the microphthalmic rat we found the total volume and neuronal population were reduced by 45 and 68% of normal values, respectively. The size of normal LGNd neurons was 8 to 20 microns and that of mutant LGNd cells from 6 to 16 microns. Neurons of the normal LGNd were medium-size and round or oval, and their cell bodies were filled with Nissl substance. Microphthalmic LGNd neurons, on the other hand, had narrow cytoplasmic spaces with few Nissl granules, and pale cell nuclei. In the microphthalmic rat, the lateral part of the ventral lateral geniculate nucleus (LGNvl) also showed a marked reduction in the total volume and neuronal population which were 42 and 76% of normal values, respectively. The size of normal LGNvl neurons was 8 to 20 microns and that of the microphthalmic neurons from 6 to 16 microns. These findings suggested that a marked reduction in the size of the LGNd and LGNvl in the mutant can be attributed to a decrease in neuronal population to a diminution of cell size.

Animals↗
PubMed1984

Quantitative analysis of the striate cortex in the mutant microphthalmic rat.

A quantitative analysis of the striate cortex of the mutant microphthalmic rat was conducted to determine whether or not transneuronal changes of the visual cortex were induced following the loss of eyes. The area of the striate cortex in the microphthalmic rat was approximately 60% of that in the normal rat. As for the thickness of each layer of the striate cortex, many layers of microphthalmia tended to be thin in comparison with the normal animal, except for layers I and III: the thickness of layers II, IV, V, and VI was about 74, 62, 82, and 82% of normal values, respectively. There was fractically no difference between the number of neurons of each layer of the microphthalmic and the normal striate cortex per unit (10(4) microns2), except for layer IV, in which the density had increased to 117% of the normal value. In many layers, the neurons of the microphthalmic striate cortex were smaller than normal and they had narrow neuroplasmic space. Our study demonstrated that the striate cortex of the microphthalmic rat underwent quantitative and morphometric transneuronal changes. Especially striking changes of the striate cortex were found in the inner granular layer with a reduction in thickness and a diminution of cell size.

Animals↗
PubMed1986

Geniculotectal neurons of the lateral part of the ventral lateral geniculate nucleus in the hereditary microphthalmic rat: a retrograde WGA-HRP study.

The distribution and morphological characteristics of the geniculotectal neurons from the lateral part of the ventral lateral geniculate nucleus in the hereditary microphthalmic rat were examined by the WGA-HRP method. Unilateral injection of the tracer into the microphthalmic superior colliculus showed that WGA-HRP-positive neurons were present in the ipsilateral lateral part of the ventral lateral geniculate nucleus. However, the number of labeled geniculotectal neurons of the microphthalmia was about 50% that of the normal rats. Furthermore, the size of labeled geniculotectal neurons of the microphthalmia was smaller and their dendrites were shorter than those of normal rats. These results demonstrated that, although geniculotectal neurons of the microphthalmic lateral part of the ventral lateral geniculate nucleus could differentiate just as in the normal rat, the size and number of microphthalmic geniculotectal neurons were remarkably smaller and fewer than those of normal rats. Moreover, the dendrites of microphthalmic geniculotectal neurons were less branched than usual.

Animals↗
PubMed1987

Anomalous optic nerve fiber convergences in the ipsilateral retinocollicular projection: a comparison of congenitally monocular and neonatally one-eye-removed rats.

Single cell responses to electrical stimuli applied to the optic chiasm and to the lateral geniculate nucleus were studied in expanded projection to the ipsilateral superior colliculus of neonatally enucleated and congenitally monocular rats. In both types of rats latencies to the afferent volleys were longer, and the latency correlation between the optic chiasm and the lateral geniculate responses was lower in the ipsilateral than in the contralateral superior colliculus cells. This was interpreted to suggest abnormal convergence of retinal axons with different conduction velocities in the ipsilateral retinocollicular projection. The deviation of ipsilateral superior colliculus cells from the high-latency correlation of the contralateral cells was more marked in congenitally monocular than in neonatally enucleated rats.

Action Potentials↗
PubMed1987

Quantitative analysis of the oculomotor nuclei in the mutant microphthalmic rat.

A quantitative analysis of the oculomotor, trochlear, and abducens nuclei was carried out in the mutant microphthalmic rat. In this strain of rat, the eyeball is reduced to about one-third in diameter, and there is no optic nerve. Nevertheless, this strain possesses all the types of extraocular muscles; however, the volume of these muscles is reduced from 33 to 74% of the normal values. The oculomotor, trochlear, and abducens nuclei in this mutant rat were found in the same location as in the normal ones. Moreover, the neurons in these nuclei in the microphthalmic rat did not appear to be any different from those in the controls. The neuronal population of these nuclei was reduced by 63% (oculomotor), 50% (trochlear), and 61% (abducens) of normal values, respectively. The long axis of all neurons of these nuclei in the microphthalmic and normal rats was measured. In all three nuclei of both strains, the size histograms showed a unimodal distribution ranging from 10 to 35 micron, with peaks at 20 to 25 micron. There was no significant difference between the normal and mutant strains. Consequently, the only influence of the shrinkage of the muscles which they supply was seen in the reduction of the cell populations of these nuclei.

Abducens Nerve↗