Histochemical demonstration of cyclic guanosine 3',5'-monophosphate phosphodiesterase activity in retinal photoreceptor outer segments.

A technique for the histochemical demonstration of cyclic guanosine monophosphate phosphodiesterase in retina is described. Enzyme activity was identified on photoreceptor outer segment lamellae, a finding in agreement with previous biochemical data on isolated outer segment preparations. The distribution of phosphodiesterase activity for cyclic guanosine monophosphate was similar to that found previously in rod outer segments for cyclic adenosine monophosphate, suggesting that the same enzyme may hydrolyze both nucleotides.

Regional changes in retinal pigment epithelial cell density during ocular development.

The density of retinal pigment epithelial (RPE) cells in various parts of the posterior segment of developing human eyes was examined. The material for study consisted of 19 autopsy eyes, ranging in age from the sixth gestational month to 6 postnatal years. Whereas RPE cell density gradually increased in the macular area up to 6 months of age, cell density dropped in all other areas of the posterior segment through the first 2 postnatal years. The decrease in cell density was especially marked near the ora serrata. Mitotic figures were rarely seen and only found in the eyes of preterm infants. The author concludes that the increase in total surface area of the RPE during the period studied is primarily accounted for by changes in the regional density of the existing cell population. A centripetal shifting of cells toward the macular area from more peripheral areas would account for the increasing density in the posterior pole.

Ocular retardation (or) in the mouse.

The ocular retardation (or) mutation in mice has been studied morphologically in serial 1 mu sections. This recessively inherited, fully penetrant mutation is characterized by an early arrest of retinal development, aplasia of the optic nerve, cataractous degeneration of the lens, and microphthalmia. We describe early alterations of normally occurring morphogenetic cell death in the optic cup and aberrations of optic fissure formation which appear to precede the arrest of retinal and optic nerve development. The subsequent disappearance of central retinal vessels and cataract formation are interpreted as secondary phenomena.

Probing and irrigation for congenital nasolacrimal duct obstruction.

I reviewed the results of probing for congenital nasolacrimal duct obstruction in a series of 107 patients, with special reference to age at the time of probing. Relief of tearing and discharge was achieved in 90% of patients with the first probing, and an additional 6% were cured after a second probing. Altered nasolacrimal duct anatomy seemed to account for probing failures rather than any delay in probing. Primary probing continued to be an effective treatment well after 2 years of age and was successful in two 5-year-old patients. Unsuccessful probings were usually apparent at the time of the initial probing and were characterized by difficulty passing the probe and subsequent inability to irrigate saline through the nasolacrimal system into the nose. Dacryocystorhinostomy was an effective secondary procedure in the few patients in whom probing was unsuccessful.

Development of myelin in human optic nerve and tract. A light and electron microscopic study.

The early development of myelin in human optic nerve and tract was studied in plastic-embedded material from post-mortem examinations of 18 infants and children. Specimens were examined by light and electron microscopy, and a good correlation was found between the data obtained by the two techniques. The characteristic lamellae of myelin were first seen around a few fibers of tract and intracranial optic nerve at 32 weeks of gestation. By term, these myelin sheaths had become thicker, and a majority of the nerve fibers had become myelinated. In the optic nerve near the globe, myelin was first seen at term and virtually all fibers were myelinated by 7 months of age. Significant increases in sheath thickness were seen in the first two years, and modest increases were found thereafter. These results are in agreement with earlier observations that, in the optic nerve, myelination proceeds from the brain toward the eye. The present data suggest that a significant amount of myelination in the human optic nerve occurs after a full-term (40-week) gestation, during a period of rapid postnatal visual development.

Pathology of the Lens in Down's syndrome.

A pathological study of the lenses of 21 patients with Down's syndrome disclosed no distinctive abnormalities of the lens capsule, as had been reported previously. Five patients, 15 years of age or older, had focal cortical changes consistent with the characteristic flake-like opacities seen in patients with Down's syndrome after the first decade of life. Three patients with more extensive, visually significant lens opacities showed nonspecific cataractous changes. No abnormalities other than pathological artifacts were seen in the lenses of patients younger than 15 years of age.

Isolated foveal hypoplasia.

Although defective development of the fovea has long been known to occur in patients with aniridia and albinism, only rarely has isolated foveal hypoplasia unassociated with these conditions been reported. We have identified such foveal hypoplasia in nine patients with varying degrees of congenital nystagmus and poor visual acuity, but no evidence of albinism or aniridia, isolated foveal hypoplasia may be more common as a cause of congenital sensory nystagmus than has been appreciated in the past.

Visual prognosis in patients with ruptures in Descemet's membrane due to forceps injuries.

Seven patients with Descemet's membrane ruptures associated with a forceps injury to the eye at birth were studied. A complete ophthalmological examination was done on each patient, and two patients had ultrasound measurements of the axial lengths of both eyes. We found that the ruptures in Descemet's membrane were single or multiple vertically oriented breaks associated with high astigmatism along the axis of the breaks and deep amblyopia in all patients. The astigmatic errors were corneal in origin. High myopia was also present in the involved eye and was thought to be axial in all patients. Two patients did have elongated axial lengths demonstrated by ultrasonography. The presence of axial myopia and deep amblyopia may relate to partial occlusion of the involved eye during the early postnatal months. The latter possibility is discussed in light of recent reports of myopia induced by early postnatal occlusion in animals.

Spontaneous absorption of the lens in the congenital rubella syndrome.

Seven eyes in five patients with the congenital rubella syndrome have shown partial or complete absorption of a cataractous lens without surgical intervention. The rare occurrence of spontaneous lens absorption should not be a reason for delaying the early removal of dense bilateral cataracts in this condition.

Vitreous hemorrhage complicating retinal astrocytic hamartoma.

Tuberous sclerosis classically presents a triad of mental deficiency, seizures and adenoma sebaceum. Among the ocular manifestations are astrocytic hamartomas in the retina. This paper describes the case of a 24-year-old man with tuberous sclerosis who had recurrent vitreous hemorrhage from a large epipapillary astrocytic hamartoma in the left eye. Pars plana vitrectomy cleared the vitreous and bimanual bipolar coagulation of tumor bleeding points was done. Fragments of the friable tumor were obtained with the vitrectomy instrument and were prepared for tissue culture, histology, and electron microscopy. Although pars plana vitrectomy offers certain advantages over other methods of biopsy, it does present a danger of extraocular seeding of malignant cells; therefore, it is not recommended in cases with probable intraocular malignancy.

Refractive errors associated with hemangiomas of the eyelids and orbit in infancy.

Asymmetrical refractive errors, both astigmatic and myopic, were associated with infantile hemangiomas of the eyelids and orbit in 46% of 37 patients who had large lesions and upper eyelid involvement predisposing to the ammetropia. The axis of the astigmatic error related to the location of the eyelid hemangioma and correlated closely with keratometric measurements of corneal astigmatism. The refractive errors tended to be stable despite eventual resolution of the hemangiomas. Efforts to combat strabismic and refractive amblyopia were rewarding in many patients. A history of complete eyelid occlusion during part of the first year of life was associated with dense amblyopia and eccentric fixation in some patients, but in other patients this history was compatible with the eventual development of useful vision. Absence of an asymmetrical refractive error in patients with eyelid and orbital hemangiomas rendered the prognosis for vision good in involved eyes.

Keratoconus and acute hydrops in mentally retarded patients with congenital rubella syndrome.

Four patients with the congenital rubella syndrome had keratoconus and evidence of acute or previous corneal hydrops. All four of the patients vigorously rubbed and poked their eyes. The keratoconus and acute corneal hydrops in these patients probably resulted from chronic traumatizing mannerisms common in other patients with mental retardation and are not specific for the congenital rubella syndrome.

Ocular manifestations of group A Niemann-Pick disease.

Four infants with Group A Niemann-Pick disease had similar ocular abnormalities secondary to this systemic disease. Each child demonstrated corneal opacification, brown discoloration of the anterior lens capsule, and retinal opacification with a macular cherry-red spot. These abnormalities were seen in each child during the first year of life and appeared stable. Recognition of this combination of ocular defects facilitates early identification of patients with Group A infantile Niemann-Pick disease.

Retinal degeneration in vitamin B12 disorder associated with methylmalonic aciduria and sulfur amino acid abnormalities.

A 33-month-old boy with an inborn error of vitamin B12 metabolism characterized by methylmalonic aciduria, homocystinuria, cystathioninuria , and hypomethioninemia had poor vision and a progressive retinal pigmentary degeneration. The child had early growth retardation with microcephaly, developmental delay, and a megaloblastic anemia. The retinal lesions were first noted when he was 1 year of age and, by ophthalmoscopy and by electroretinographic testing, have progressed. Treatment with hydroxocobalamin and L-methionine improved the anemia and the biochemical abnormalities but apparently did not halt the retinal degeneration. We believe the retinopathy is a feature of this disease, particularly in patients with infantile involvement. The retinal lesion may be caused by an unidentified abnormality of sulfur amino acid metabolism.

Unique hereditary sensory and autonomic neuropathy with growth hormone deficiency.

The proband, a French-Canadian white boy, presented with congenital sensory polyneuropathy, moderate to severe sensorineural hearing loss, infantile cataracts, nystagmus, esotropia, unusual facies, hypotonia, bilateral congenital hip dysplasia, delayed ossification of the femoral heads, scoliosis, short stature secondary to growth hormone deficiency, and developmental delay. His parents are consanguineous. His maternal first cousin, a 16-year-old girl, has congenital sensory polyneuropathy, infantile cataracts, unusual facies, scoliosis, short stature secondary to growth hormone deficiency, late-childhood-onset arthritis, and hypoglycemia. Reportedly, she has no hearing difficulties and has normal intelligence. Her parents are third cousins. These children appear to have a distinct variant of hereditary sensory and autonomic neuropathy with infantile cataracts, unusual facies, skeletal dysplasia, short stature secondary to growth hormone deficiency, and other features, with probable autosomal recessive inheritance.

Special diagnostic and therapeutic modalities in pediatric ophthalmology.

Ophthalmology is a specialty rich in instrumentation used for special diagnostic and therapeutic functions. Many of these special modalities are appropriate to pediatric ophthalmology, and this article discusses them in summary fashion for those who may wish to know about the procedures but who may not be involved directly in their use.

Congenital nasolacrimal duct obstruction.

Congenital nasolacrimal duct obstruction is a common problem among infants. Its incidence and natural course are reviewed. Probing techniques and various back-up procedures for failed probings are discussed. Additional suggestions are made about the management of lacrimal duct obstruction with congenital cacryocystocele and nasal dacryocele.

Ocular dermoids.

The following types of ocular dermoids were seen in a retrospective study of 50 children with these lesions: 34 epibulbar dermoids, 12 lipodermoids, and 4 dermoid cysts. Forty-six percent had hemifacial microsomia, and one-half of these had additional stigmata of the Goldenhar variant of the syndrome. Ninety-seven percent of the dermoids were found in the temporal half of the globe; of these, 76 percent were in the inferolateral quadrant, straddling the corneoscleral limbus. The majority of children had an oblique astigmatism in the involved eye. Epibulbar dermoids may be removed by careful superficial keratectomy, but caution should be exerted in excising lipodermoids because of the risks of affecting ocular motility and tear secretion.

Astigmatic refractive errors associated with limbal dermoids.

A retrospective review of 17 patients with limbal dermoids revealed that 13 (76%) had astigmatism of 1.00 diopter or greater in the involved eye. In all but one patient, the minus cylinder axis of the astigmatism coincided with the location of the dermoid. Thirteen patients had surgery to remove the dermoids at ages ranging from 8 months to 15 years. The preoperative astigmatism persisted postoperatively with little change in its orientation or amount regardless of age at the time of surgery.

Increase in retinal surface area during infancy and childhood.

Retinal surface area was calculated from measurements made on the eyes of 33 patients ranging in age from six-months of gestation to six-postnatal years. Retinal surface area increased dramatically during the last months of gestation and more gradually in the first two postnatal years. Thereafter the rate of increase was small. These data provide a background against which regional shifts in the cell density of the retina and retinal pigmented epithelium can be studied.