Open globe injuries in children: a retrospective analysis.

PURPOSE: To study the outcome of open globe injuries in patients aged <14 years and compare the results between patients who presented approximately 30 years ago and a recent series. METHODS: Between January 1970 and January 1993, 180 eyes of children who presented with an open globe injury were retrospectively analyzed. Patients were divided into two groups. One group of children underwent treatment of an open globe injury between January 1970 and December 1981 (group A) and another between December 1985 and January 1993 (group B). Main outcome measures studied were final visual acuity and enucleation rates. Risk factors studied included age, race, sex, visual acuity, type of trauma, and various injury characteristics at presentation. RESULTS: The factors associated with visual outcomes included: age, type of injury, wound size, initial visual acuity, and retinal detachment. Final visual outcome and enucleation rates were not significantly different between the older series (group A) and the recent series (group B). Lenticular damage, location, posterior extent of the injury, and presence of an intraocular foreign body had been significant prognostic factors in the older series, but were not statistically associated with the prognosis in the recent series. CONCLUSION: The nature of the injury and the patient's age are the main determining factors in the outcome of open globe injuries in children.

Adult-onset foveomacular pigment epithelial dystrophy: clinicopathologic correlation of three cases.

PURPOSE: The authors describe the clinicopathologic features of three patients with adult onset foveomacular pigment epithelial dystrophy (AOFPED). METHODS: The eyes of three patients were studied ophthalmoscopically and by fluorescein angiography, and obtained postmortem and studied by light and electron microscopy. RESULTS: Histopathologic study of the three patient's eyes disclosed central loss of the retinal pigment epithelium and photoreceptor cell layer with a moderate number of pigment-containing macrophages present in the subretinal space and outer retina. To either side, the retinal pigment epithelium was distended with much lipofuscin. Basal laminar and basal linear deposits were present throughout the central area. No discontinuities of Bruch membrane were present. CONCLUSION: The findings in the eyes of three patients with AOFPED included marked aging changes that are similar to those seen in age-related macular degeneration. Pigmented cells with lipofuscin in the subretinal space account for the vitelliform appearance.

Morphometric analysis of pars plana development in humans.

BACKGROUND: Quantitative features of pars plana development in humans are not well characterized. Knowledge of the dimensions of this region is important for our understanding of the anatomy of infant eyes for the purposes of surgery. The purpose of this study was to provide a morphometric description of pars plana growth in relation to 1) postconceptional age and 2) axial length. METHODS: We reviewed histologic specimens from 204 human eyes of postconceptional ages ranging from 10 weeks to 5 years. Axial length and temporal pars plana width were measured directly with a reticule system. The relationships among pars plana width, axial length, and postconceptional age were examined. RESULTS: The most rapid phase of pars plana growth occurred between 26 weeks and 35 weeks gestation. A linear relationship between pars plana width and axial length existed once the axial length reached 12 mm (correlation coefficient = 0.918; P = 0.0001). In infants of 38-42 weeks postconceptional age, mean pars plana width was 1.87 mm (range, 0.9-2.8 mm; standard direction = 0.48 mm), and mean axial length was 17.7 mm (range, 15-23 mm; standard direction = 1.9 mm). After the age of 62 weeks postconception, all eyes had a temporal pars plana width > or = 3 mm and an axial length > or = 19 mm. The estimated age at which there was a 95% chance of the pars plana width being > or = 3 mm was 64.4 weeks (95% fiducial confidence limits, 60.8-86.2 weeks). CONCLUSIONS: The pars plana first develops during the second trimester of gestation. A rapid growth phase occurs between 26 weeks and 35 weeks postconception. The dimensions of the pars plana are correlated closely with axial length and postconceptional age. Assuming that a pars plana width of 3 mm is required for surgery to be performed via a pars plana approach, we estimate that pars plana vitreous surgery can be performed when the patient is at least 62 weeks old (postconception), which is a 6-month-old full-term infant.

Effects of the human immunodeficiency virus type 1 Rev protein on reporter gene and host T-cell gene expression.

The HIV-1 encoded regulatory Rev protein acts to selectively increase the cytoplasmic concentration of incompletely spliced viral mRNAs through interaction with the Rev responsive element (RRE). In addition, the Rev activation domain, believed to be a nuclear export sequence, has been shown to modulate the export of non-RRE containing RNAs (e.g. 5S rRNA, splicesomal U snRNAs). Recent evidence suggests Rev activity depends on interactions with cellular cofactors, leading to speculation that Rev utilizes a cellular RNA and/or a protein export pathway. Rev interactions with cellular cofactors could lead to sequestration of those cofactors from normal cellular activities, suggesting potential Rev effects on cellular gene products and their resultant activity. We have examined the role of Rev in modulating the expression of cellular gene products. Through transient cotransfection assays, we observed a consistent and significant decrease in the levels of luciferase and B-galactosidase activity in the presence of a Rev expressing construct. Cell fractionation studies demonstrated the nuclear retention of the luciferase gene transcripts. Surprisingly, similar effects were observed on constitutively expressed RNAs such as gamma-actin transcripts, and the 18S and 28S rRNAs. These results suggest Rev can disrupt the nuclear export of multiple classes of RNAs.

The management of cytomegalovirus-associated retinal detachments.

AIDS: Various surgical treatments exist for correction of retinal detachment resulting from cytomegalovirus (CMV) infection. The following methods of treatment are examined: laser photocoagulation, pneumatic retinopexy, scleral buckle, and vitrectomy. While earlier surgical attempts to correct retinal detachments were discouraging, recent attempts have been favorable. The differences in surgical results may be related to the time between diagnosis of a retinal detachment and surgical repair, indicating that early intervention may be associated with more favorable outcomes.^ieng

Protoporphyrin IX photosensitization of corneal endothelium.

Protoporphyrin IX, a naturally occurring precursor of hemoglobin found in serum and erythrocytes, is a photoactive compound that we have detected in aqueous aspirates of three patients with hyphemas (0.13, 0.33, and 0.67 microgram/dL). To determine whether corneal endothelial photosensitization could occur, rabbit corneas were exposed to physiologic concentrations of protoporphyrin and light (200 microEinsteins [microE]/m2 per second). Experimental corneas demonstrated endothelial swelling with loss of intercellular contact by scanning electron microscopy. Flux chamber experiments demonstrated an increase in the net endothelial inflow, indicating a loss of the endothelial barrier function. Control corneas had normal ultrastructural architecture and flux study results. These studies suggest that patients with long-standing hyphemas who may be exposed to long periods of light are possibly at risk for developing endothelial dysfunction and corneal blood staining. Patching of these patients' affected eyes may be prudent.

Corneal alanine metabolism demonstrated by NMR spectroscopy.

This study confirms the feasibility of monitoring corneal metabolism of an amino acid using high resolution NMR spectroscopy. Alanine metabolism to lactate was detected in intact, freshly isolated rabbit corneas. Progressively decreasing alanine resonances were noted after 4-5 hours of incubation while increasing amounts of lactate were detected. No similar signal was noted in de-epithelialized tissue. This study demonstrates the ability of corneal epithelium to utilize alanine as a metabolic substrate. This technique may be useful to determine the essential amino acids and their optimal concentrations necessary to maintain corneal viability during storage.