Biomedical subjects
Publications and source records attributed to G W Cibis.
A family with total (internal and external) ophthalmoplegia had associated iris transillumination. No abnormal visual-evoked response brain lateralization indicative of albinism was found. On the basis of avian chimera experiments showing iris muscles to be derived from neural crest cells, we proposed a neurocristopathic theory to explain all clinical findings in this family.
We conducted a prospective study for over 2 years to determine the incidence of perforations following strabismus surgery. All eyes were examined by indirect ophthalmoscopy and indentation immediately after surgery in an attempt to identify perforation sites. No cryotherapy or treatment was done. None of the 10 perforations identified was associated with retinal detachment or endophthalmitis. The incidence of perforations was 2.8% on a per-case basis and under 1% on a per-muscle basis.
We treated a bilateral, well-differentiated neuroblastoma of the choroid in a patient who had congenital abdominal neuroblastoma. Although orbital metastasis of neuroblastoma is common, intraocular metastasis is not. In our patient, there was no amplification of the N-myc oncogene in the tumor of either eye. This is consistent with early-stage primary neuroblastoma. Histologically, the tumors were identical in each eye and well differentiated with Homer Wright rosettes; most neuroblastoma metastases have few rosettes and are composed of more undifferentiated, anaplastic cells. We believe that our patient had bilateral primary tumors and not metastatic tumors.
A full-term infant boy had proptosis OS at birth: A large solid tumor mass was found by examination and computed tomographic scan in the orbit and extended intracranially. Biopsy showed spindle-shaped tumor cells that, with electron microscopy, proved to be myofibroblasts. Congenital fibromatosis (myofibromatosis) is a benign localized tumor of which this case is a striking example.
Congenital and juvenile glaucoma are associated with goniodysgenesis and currently thought to be the result of neural crest cell abnormal terminal induction or migration. Infantile glaucoma may be primary, or may be associated with syndromes such as Sturge-Weber, Rieger's and others. Differentiation from other childhood causes of cloudy cornea such as endothelial dystrophies is essential. Evaluations under anesthesia are often needed and present their own problems in diagnosis.
Based on our morphologic and ultrastructural studies, we suggest that the characteristic lens opacities in Lowe's syndrome result from a genetic defect in the lens cells. This defect manifests early in embryogenesis, and the progression of the lens opacities is related to both the inherent genetic abnormality and the prevailing extralenticular environment. The defective formation and subsequent degeneration of the primary posterior lens fibers account for their loss and for the flattened, discoid, or ring-shaped cataract. The other findings, such as anterior polar cataract, subcapsular fibrous plaque, capsular excrescences, bladder cells, and posterior lenticonus are not necessarily specific for Lowe's syndrome. We believe that the pathogenesis of Lowe's cataract can be explained by Lyon's hypothesis, which implies that, very early in embryogenesis (at the stage of the primitive streak), one of the two X chromosomes in females is deactivated. We consider the high incidence of lens opacities in female carriers to be due to this random deactivation. In male probands, however, all lens cells are affected, since there is no normal X chromosome to nullify the effect of the Lowe gene.
Eleven possible and five obligate carriers of Lowe's syndrome from the same pedigree were examined for lens opacities. All of the obligate carriers and 4 of the 11 at risk had lens abnormalities. The lenticular abnormalities consisted of cortical dots of various shapes that increased in number with the age of the carriers in older obligate carriers, subcapsular plaques were common. Because the syndrome is X linked, such lens changes are explainable by the Lyon's hypothesis. When the number of opacities seen in these subjects were compared to those seen in 100 normal control females 10 to 20 years of age, cataractagenic cases such as diabetes, Down's and fetal nuclear opacities excluded, four probable carriers were identified among the eleven possible carriers in the pedigree. These subjects had significantly greater numbers of opacities, similar to those seen in obligate carriers, compared to controls. We conclude that progressive lens changes are present in carriers of Lowe's syndrome and that young carrier females can be identified reliably when they are compared to age-matched controls by modifying the grading system of Brown and Gardner.
We encountered two clinically similar but genetically unrelated cases of a disorder characterized by an unusual white pupillary-iris-lens membrane with extension to a prominent Schwalbe's line, the membranes were vascularized and their appearance changed over time. In both cases the abnormality was unilateral. Anomalous chamber angles were seen on gonioscopy. The clinical appearance is similar to a combination of iridogoniodysgenesis and pupillary membrane. However, our two cases are unique and fit into neither category. We postulate that this is a new entity consisting of an anomalous chamber angle and iris-lens membrane resulting from a localized iris (pupillary membrane), infarct with secondary neovascularization, during formation of the chamber angle.
"I thought I saw my child's eyes turning" is a frequent observation of parents. The Brueckner test is a simple method, easily learned, to determine the presence or absence of true strabismus. With some practice, an observer can uncover strabismus and amblyopia. This test makes use of a direct ophthalmoscope and the same corneal reflexes one is familiar with in pen light testing. The position of the corneal light reflex is an important portion of the Brueckner test, but the additional, definitive information is derived from the red reflex that fills the entire pupil and gives an excellent backdrop to the bright white dot that is the corneal light reflex. The eye that is turned in or out will have a brighter, more orange-red reflex and the appearance of increased pupil size. Even with pseudostrabismus or unusual angle kappas, the equality or inequality of the red reflex determines the absence or presence of true strabismus. With practice, the Brueckner test can yield the doctor an answer to one of the most common parental concerns.
The clinical presentation of a congenital mucocele is a blue-gray tense mass located inferior to the medial canthal ligament. The differential diagnosis is that of tumor and encephalocele. Diagnostic modalities such as simple transillumination and ultrasound aid the physician, but dacryocystography confirms the marked lacrimal sac distension. In three infants the sac could not be decompressed by massage, indicating that the canalicular-punctal system as well as the inferior lacrimal system were blocked. When the distended lacrimal sac compresses the two canaliculi and bends them on themselves, there is a functional trapdoor-type block. During the probing of these patients, we felt a snap when the lacrimal syringe was withdrawn from the distended sac. We concluded that this was due to kinking of the canaliculus by the enlarged sac.
A white boy, born at the gestational age of 39 weeks, had Peters' anomaly in association with a ring 21 chromosomal abnormality. Dysmorphic features included low-set ears, hypoplastic mandible, delicate, dry skin, narrow arched palate, wide spaced nipples and hypotonia. He also had a cloudy right cornea. Chromosomal analysis disclosed a ring 21 defect. The cornea had a paracentral white opacity with a loss of posterior stroma and no adherence of the iris to the leukoma. Intraocular pressure, the lens, and the posterior pole were normal.
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We studed the clinical and histopathologic findings in two congenital iris cysts, one in a 19-month-old girl and one in a 7-year-old boy. Our second case showed the resilience of these lesions, with the cyst returning to its original size after needle aspiration, argon iridotomy, marsupialization, and excisional iridotomy. Cryogenic therapy was needed to eliminate the cyst. In both cases, histologic studies showed squamous epithelium with few (Case 1) or no (Case 2) goblet cells.
A case of intraocular extension of primary optic nerve meningioma occurred in a 13-year-old girl with neurofibromatosis. An anomalous disc in the involved blind eye was diagnosed as optic nerve glioma at 2 1/2 years of age. The aggressive nature of meningiomas in the young and the long time period involved account for this rare occurrence of direct intraocular extension.
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The Parsons visual acuity test (PVAT) uses modified Allen test targets for visual acuity assessment in young children and persons who are difficult to test. Using this method, we were able to obtain a visual acuity threshold in 44% of 18- to 24-month-old children and in 90% of children aged 25 to 36 months. At all ages tested, the mode for visual acuity was 20/30; however, the percentage of those with 20/20 increased with age. The decision whether to refer was correctly made by means of the PVAT criterion 83% of the time.
Trabeculectomy specimens from three eyes with Sturge-Weber syndrome were examined histopathologically. Changes in the trabecular meshwork-Schlemm's canal system were similar to findings in old age and in primary open-angle glaucoma. Two mechanisms for glaucoma are theorized. In cases with buphthalmos and congenital glaucoma, the chamber angle is often anomalous, as in other types of congenital glaucoma. In later onset juvenile cases, the chamber angle more often appears normal. A premature aging of the trabecular meshwork Schlemm's canal complex, as shown by us histopathologically, is a primary cause of juvenile glaucoma. It is suggested that both mechanisms relate to the abnormal hemodynamics of episclera and chamber angle, due to persistence of Streeter's primordial vascular plexus.