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Biomedical subjects

G J Jaffe

Publications and source records attributed to G J Jaffe.

98 records · Page 6Linked to original sources
PubMed1988

Histopathologic features of adult-onset foveomacular pigment epithelial dystrophy.

We studied the clinical and histopathologic characteristics of the eyes obtained after death from a patient with adult-onset foveomacular pigment epithelial dystrophy. The pigmentation seen in the central fovea corresponded histologically to a hyperplastic clump of retinal pigment epithelium. The pale yellow rim surrounding the central pigmentation corresponded histologically to dense periodic acid-Schiff-positive material underlying thinned, atrophic retinal pigment epithelium. Fluorescence microscopy demonstrated homogeneous autofluorescence in the retinal pigment epithelium that was similar in intensity to that of an age-matched control. The results of this clinicopathologic study suggest that in adult-onset foveomacular pigment epithelial dystrophy, an alteration of macular retinal pigment epithelium causes an accumulation of abnormal subretinal pigment epithelial material, photoreceptor degeneration, and serous retinal detachment.

Aged↗
PubMed1988

Intravitreal clearance of tissue plasminogen activator in the rabbit.

The clearance of tissue plasminogen activator (t-PA) injected into the midvitreous cavity was studied in the phakic, vitrectomized rabbit eye with and without intravitreal fibrin clots. The quantity and activity of t-PA in the vitreous, serum, and aqueous were determined at ten minutes and at 3, 6, 15, 24, and 48 hours after initial injection by an enzyme-linked immunosorbent assay (ELISA) and a spectrophotometric solid-phase fibrin assay (SOFIA). In eyes without an intravitreal fibrin clot, the estimated half-life for t-PA was 4.3 hours by SOFIA and 5.8 hours by ELISA. In eyes containing a vitreal fibrin clot, the half-life increased to 9.8 hours by SOFIA and 11.9 hours by ELISA. Both of these half-lives were significantly greater than the half-life for eyes without fibrin. Regardless of the presence of fibrin, intravitreal t-PA activity was significantly less than t-PA quantity, suggesting the presence of a t-PA inhibitor. A peak in aqueous t-PA occurred before six hours, indicating that t-PA was cleared in part through the anterior chamber. There was no measurable serum t-PA at any of the sampling times.

Animals↗
PubMed1988

Retinal phototoxicity from the operating microscope. The role of inspired oxygen.

The effect of the inspired oxygen concentration (FIO2) on the production of retinal phototoxicity by the operating microscope was studied in phakic rhesus monkeys. One eye of each monkey was exposed to light under conditions of 99% FIO2, and the other eye was exposed under 21% oxygen (O2). Three of four locations on each retina were exposed to light for durations varying from 1 1/2 to 20 minutes per exposure. Fundus photographs and fluorescein angiograms were obtained 24 to 72 hours after exposure. Animals were euthanatized for analysis of retinal histopathology at intervals from 2 weeks to 8 months after light exposure. Retinal phototoxic lesions were produced after an average of 5 minutes of light exposure under both 21 and 99% O2. O2 potentiated the light damage both clinically and histologically. Under both conditions, lesion size was directly related to the duration of light exposure (P less than 0.005). Lesions near threshold produced with 99% FIO2 were 1.6 to 6.9 (mean, 2.9) times larger than the corresponding lesions formed with 21% FIO2. Histologic damage was likewise more severe in lesions produced under high O2 conditions. Retinal repair occurred in lesions produced under high and low O2 conditions. Photoreceptor regeneration was nearly complete by 18 weeks, whereas retinal pigment epithelial (RPE) recovery lagged up to 1 1/2 months. The results of this study have important implications for clinical practice: the operating microscope can produce retinal phototoxicity rapidly, and O2 administered during ophthalmic procedures may potentiate the damage if appropriate precautions are not taken.

Animals↗
PubMed1986

Age-related changes of the normal visual field.

We prospectively studied the age-related changes of the visual fields obtained from a selected group of 25 normal patients. The OCTOPUS automated perimeter was used to test both eyes of each patient using Program 32. We calculated the mean threshold sensitivity, volume, and surface area of the visual field and measured a linear decline with age for all three characteristics. The age-related decline in threshold sensitivity and the SE of this decline increased with eccentricity from fixation. Sensitivity declined approximately twice as rapidly at 30 degrees eccentricity as it did at fixation. The general decline in sensitivity of the visual field and the increased rate of decline with eccentricity may be related to a functional or anatomic loss of photoreceptors, ganglion cells, and higher structures.

Adult↗
PubMed1986

Propionibacterium acnes endophthalmitis seven months after extracapsular cataract extraction and intraocular lens implantation.

We present a case of endophthalmitis caused by Propionibacterium acnes seven months following extracapsular cataract extraction and intraocular lens implantation. The markedly delayed clinical course of endophthalmitis associated with this organism appears to be highly stereotypical. Recognition and treatment of this complication of cataract surgery allows an excellent chance at cure.

Ampicillin↗
PubMedDate not supplied

Collagen shield delivery of tissue plasminogen activator: functional and pharmacokinetic studies of anterior segment delivery.

BACKGROUND: Postoperative fibrin formation remains a major complication associated with intraocular surgery, especially after vitreoretinal surgery for proliferative vitreoretinopathy, proliferative diabetic retinopathy, trauma, or endophthalmitis. Tissue plasminogen activator (tPA) has been shown, both in experimental studies and clinical trials, to specifically dissolve formed intraocular fibrin after intracameral or intravitreal injection. We studied collagen shield delivery of tPA to the anterior segment and vitreous of rabbit eyes to evaluate a noninvasive delivery modality. METHODS: Anterior segment fibrin clots were formed in rabbit eyes by injecting citrated rabbit plasma. The tPA hydrated collagen shields, or control shields, were then placed on the rabbit corneas and the extent of fibrin clot was followed. In other rabbit eyes, tPA hydrated collagen shields were placed on the rabbit corneas and an enzyme-linked immunosorbent assay (ELISA) was utilized to determine aqueous, vitreous, and blood levels of tPA over time. RESULTS: Collagen shield tPA delivery shortened the time to fibrin clot lysis by 50% (mean clearance time = 49 +/- 23 hours; P less than .05). ELISA for tPA levels noted measurable vitreous levels by 2 hours after tPA hydrated collagen shield application with a peak at 24 hours. Aqueous tPA levels were not measurable until 18 hours after tPA collagen shield application and peaked at 36 hours. Vitreous tPA levels were greater than aqueous tPA levels at all time points (P less than .05). No evidence of corneal edema or opacification, hemorrhage, or cataract was seen. CONCLUSIONS: These results document the efficacy and safety of tPA delivery to the aqueous and vitreous via a hydrated collagen shield in this animal model.

Absorption↗