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Biomedical subjects

R D Stulting

Publications and source records attributed to R D Stulting.

At least 91 records · Page 5Linked to original sources
PubMed1987

Penetrating keratoplasty for herpes simplex keratitis and keratoconus. Allograft rejection and survival.

To determine the relationship between corneal allograft rejection and failure, we studied patients who underwent penetrating keratoplasty for herpes simplex keratitis (n = 82) and keratoconus (n = 345), two frequent indications for keratoplasty in young patients, using survival analysis. For first grafts for herpes, the probability of survival was significantly less than it was for keratoconus (P less than 0.0001). For second grafts, this difference was less pronounced, and for three or more grafts, the difference in survival was not significant. The incidence of rejection episodes was similar in first grafts for herpes (16.6%) and keratoconus (18.5%) (P greater than 0.05). However, the incidence of rejection episodes in regrafts for herpes was significantly greater than in keratoconus (23.7 versus 17%, P less than 0.01). The incidence of failure after rejection episodes (first grafts and regrafts combined) was significantly greater in grafts for herpes (52.4 versus 16.2%, P less than 0.001). Because survival after multiple regrafts in both groups is poor, additional measures, such as tissue matching, may be necessary to improve the likelihood of success in these high-risk cases.

Adolescent↗
PubMed1987

Survival of corneal grafts from donors supported by mechanical ventilation.

Eighty-five patients undergoing penetrating keratoplasty with tissue from donors supported by mechanical ventilation (Ventilator group) were compared to a surgeon- and diagnosis-matched group (Control group). Age at surgery, duration of follow-up, and sex of recipient patients were similar in the two groups. The mean donor age in the Ventilator group (26.4 years) was significantly less than in the Control group (45.8 years, P less than 0.0001). Mean time on the ventilator was 99.4 hours (range, 4 hours to 21 days). Overall graft survival rates in the Ventilator and Control groups were similar (P greater than or equal to 0.72). Time on the ventilator did not affect graft survival. Cultures of corneoscleral donor rims were positive more often in the Ventilator group than in Controls (39.7 versus 23.1%), but the difference was not significant (P = 0.09). Prolonged ventilator time was not associated with a higher rate of positive corneoscleral rim cultures, nor did positive cultures affect graft survival. The most common cause of graft failure in both groups was allograft rejection. In no case could postoperative bacterial infection be attributed to contamination of the donor material. One case of primary donor failure occurred in the Ventilator group, but the incidence (1.2%) is similar to that of previously reported studies. The data indicate that corneal tissue from ventilator-supported donors should be considered for use in penetrating keratoplasty.

Adolescent↗
PubMed1987

Corneal neovascularization. Pathogenesis and inhibition.

Corneal neovascularization (CNV) can cause significant visual loss because of the scarring and lipid deposition that frequently accompany it. In addition, penetrating keratoplasty in a vascularized recipient carries a significant risk of failure from allograft rejection. Frequently CNV is induced by nonspecific inflammatory stimuli, mediated primarily by polymorphonuclear neutrophils. Neovascularization can also be associated with specific corneal immune reactions, such as herpes simplex keratitis. Immunologically mediated CNV may be more amenable to treatment than CNV that results from nonspecific inflammation. Photodynamic therapy (PDT) following the intravenous injection of hematoporphyrin derivative or purified dihematoporphyrin ether (DHE) has been shown to suppress tumor growth and blood vessel growth in the eye. We have developed a murine model of CNV induced by the intrastromal injection of stimulated lymphocytes or interleukin-2 (IL-2). We have noted corneal DHE retention following its intravenous injection in mice with IL-2 induced CNV. Preliminary studies indicate that PDT can induce regression of CNV in these mice. Other recent studies that have enhanced our understanding of the pathogenesis and treatment of CNV are reviewed, and directions for future research are discussed.

Animals↗
PubMed1987

HSV-induced blastogenesis in splenic mononuclear cells from inbred mice.

The severity of HSV stromal keratitis varies among inbred mouse strains, with A/J and BALB/c greater than C57BL/6. Since cell-mediated immunity (CMI) is thought to play a role in the pathogenesis of HSV stromal keratitis, we measured the proliferative response of primed splenic mononuclear cells (SMC) from these strains to HSV antigen in vitro. Primed SMC from all three strains showed increased thymidine uptake after incubation with UV-inactivated HSV-1 antigen (UV-HSV) in vitro when compared with control antigen. Uptake by SMC from BALB/c and A/J mice was greater than that by SMC from C57BL/6 mice. The difference between BALB/c and A/J was not significant. Uptake by non-primed SMC cultured with UV-HSV was not significantly greater than uptake induced by control antigen. Thus, among the strains studied, A/J and BALB/c mice, which are relatively susceptible to stromal keratitis, have the greatest proliferative response to UV-HSV antigen. C57BL/6 mice, which are relatively resistant to stromal keratitis, have the least response. These findings suggest that genetically determined differences in CMI may influence the course of HSV keratitis and are consistent with the hypothesis that the host immune response plays a role in the pathogenesis of HSV stromal keratitis.

Animals↗
PubMed1987

Corneal neovascularization induced by stimulated lymphocytes in inbred mice.

The intrastromal implantation of Concanavalin A-stimulated allogeneic lymphocytes induced corneal neovascularization (CNV) in inbred C57BL/6 and BALB/c mice. Control syngeneic stimulated, allogeneic non-stimulated, and allogeneic stimulated irradiated lymphocytes were not angiogenic. CNV induced by allogeneic stimulated lymphocytes in BALB/c recipients was significantly greater than in C57BL/6 recipients. This response reflected host-versus-graft reactivity, since parental recipients responded to F1 hybrid donors, while F1 hybrids did not respond to parental donors. The ability of stimulated lymphocytes to induce CNV may be important in allograft rejection, herpes simplex keratitis, and other corneal immune reactions. The mouse cornea is an excellent model for studying immunologically mediated neovascularization under genetically controlled conditions.

Animals↗
PubMed1986

Ultrastructure of traumatic corneal endothelial rings.

Traumatic endothelial rings were observed in the cornea obtained from a 4-year-old boy after a fatal gunshot wound to the forehead. Electron microscopy showed the injury to consist of an annular area of endothelial cell loss and disruption with adherent macrophages. Endothelial cell disruption was localized to the circular area where mechanical distortion of endothelium and Descemet's membrane caused by the impact of a projectile would be maximal.

Child, Preschool↗
PubMed1986

Clinical, electron microscopic, and immunohistochemical study of the corneal endothelium and Descemet's membrane in the iridocorneal endothelial syndrome.

Two women with the iridocorneal endothelial syndrome had unilateral corneal edema, iris stromal atrophy, and glaucoma. Each underwent penetrating keratoplasty. Transmission electron microscopy of the corneal buttons disclosed a thin, normally structured Descemet's membrane bounded posteriorly by a posterior collagenous layer that contained banded and fibrillar tissue, indicating that the disorder was acquired after childhood. Scanning electron microscopy showed some degenerated corneal endothelial cells with filopodial cytoplasmic projections, suggesting endothelial migration. Transmission electron microscopy of the endothelium showed no signs of epithelial-like alteration, such as stratification, desmosomal junctions, or increased cytoplasmic fibrils. Immunohistochemical staining of fresh-frozen sections with monoclonal antibodies to keratin showed normal staining of the epithelium and no staining of the endothelium. Occasional lymphocytes were seen within the endothelium in one case but were also observed in one case of an inherited corneal disease, posterior polymorphous dystrophy, suggesting that they might be normal "passenger" cells migrating in the endothelial monolayer.

Adult↗
PubMed1986

Extended-wear contact lens correction of aphakia in infant primates. Corneal studies.

Extended-wear contact lenses (EWCL) are being used increasingly for the correction of aphakia in infants, but there is a lack of data documenting their effects on the corneas of young children. Therefore, corneal studies were performed on infant monkeys wearing EWCL for the correction of surgical aphakia. Nine newborn monkeys underwent unilateral lensectomy and anterior vitrectomy. Seven eyes were fitted with aphakic EWCL postoperatively and two wore no lenses. After at least six months, corneas were studied with slit-lamp and specular microscopy, and with light microscopy (LM) and electron microscopy (EM). Small central corneal opacities developed in two aphakic eyes corrected with EWCL after episodes of keratoconjunctivitis. One of these corneas was found to have a mildly increased coefficient of variation (CV) of endothelial cell size (polymegathism). Although EWCL are well tolerated by the corneas of aphakic infant primates, their association with endothelial polymegathism, which may indicate physiologic compromise, mandates careful long-term follow-up.

Animals↗
PubMed1986

The triple procedure. Analysis of outcome, refraction, and intraocular lens power calculation.

Presented are the results of 66 consecutive, elective, combined procedures of penetrating keratoplasty, extracapsular cataract extraction, and intraocular lens insertion (triple procedure) performed by three surgeons between January 1981 and January 1984. After a mean postoperative followup of 15.8 months, over 90% of the eyes had clear grafts, and of the 56 eyes with good preoperative visual potential, 77% achieved a best corrected visual acuity of 20/40 or better. The postoperative mean refractive deviation from emmetropia was 2.17 diopters, with a range of +6.62 D to -5.50 D, 62% falling between -2.00 and +2.00 diopters. Using multiple regression analysis of preoperative and postoperative variables, an attempt was made to derive a predictive formula for the power of the intraocular lens to be implanted during the triple procedure. In contrast to cataract surgery, where axial length and corneal power remain fairly constant preoperatively and postoperatively, penetrating keratoplasty produces marked changes in corneal curvature and power. Therefore, a single formula could not be derived to predict accurately the intraocular lens power for the patients. However, using the results for an individual surgeon, a formula was derived that could improve the predictability of intraocular lens power.

Aged↗
PubMed1986

Spread of HSV and establishment of latency after corneal infection in inbred mice.

The spread of herpes simplex virus (HSV) through neural tissues was studied in three inbred mouse strains that differ in susceptibility to HSV stromal keratitis. The left eyes of BALB/c, C57BL/6, and DBA/2 mice were inoculated topically with HSV type 1. The optic and trigeminal nerves, trigeminal ganglia, and eyes were assayed for infectious virus on days 1, 2, 3, 4, 7, 9, 11 and 14 after inoculation. At 2-4 months post-inoculation, eyes and trigeminal ganglia were assayed for latent virus. Up to 7 days post-inoculation, infectious virus was present at a similar frequency in the inoculated eyes of mice from all three strains. The quantity of virus recovered, however, was mouse strain-dependent: DBA mice yielded the most virus; C57BL/6, the least. The frequency of virus recovery and the quantity of virus recovered from trigeminal nerves and ganglia also varied according to mouse strain. Infectious virus was recovered from the uninoculated right eye of some DBA and C57BL/6 mice 1 wk after inoculation. The overall incidence of latency differed among inbred mouse strains. However, in mice that developed ocular disease (blepharitis, dendritic keratitis, or stromal keratitis), there was no host strain-related difference in the incidence of latency. These results support the hypothesis that host genetic factors play a role in controlling HSV replication and the spread of virus to neural tissues after ocular HSV inoculation. This control may influence the development and severity of disease. However, once infection occurs, latency is established in both susceptible and resistant mouse strains.

Animals↗
PubMed1986

Comparative replication of HSV-1 in BALB/c and C57BL/6 mouse embryo fibroblasts in vitro.

Herpes simplex virus type 1 (HSV)-host cell interactions were studied in fibroblasts from inbred mice by measuring virus replication, virus adsorption, infectious center formation, and single-cell virus production. BALB/c mouse embryo fibroblasts (MEF) produced more intracellular and extracellular virus than C57BL/6 MEF, with differences in virus production first appearing at 16 hr after inoculation. Virus yield in C57BL/6 cells peaked earlier (16 hr) and at a lower level than in BALB/c cells (20 hr). These results were explained by a difference in single-cell virus replication, rather than less efficient adsorption or the presence of cells that could not be infected. Host-related variation in the ability of infected cells to support HSV replication may account, in part, for differences in the severity of HSV ocular disease.

Adsorption↗
PubMed1986

Laser densitometric analysis of class I HLA antigen expression by corneal epithelium.

Laser densitometric analysis of immunoperoxidase stained tissue was used to quantitate class I HLA (HLA-A,B,C) antigen expression by human corneal epithelium. Frozen sections of human donor corneas stored in modified McCarey-Kaufman medium for less than 24 hr were evaluated for class I HLA antigen by an indirect immunoperoxidase technique using a monoclonal antibody reactive against a class I HLA antigen determinant. Photomicrographs of stained epithelium taken under standardized conditions were evaluated by laser densitometry. Measurements from peripheral and central corneal epithelium on the same tissue section were compared. Total stain, stain density, and stain intensity were higher for peripheral than for central corneal epithelium, indicating that class I HLA antigen expression is greater for peripheral than for central epithelium.

Adult↗
PubMed1985

Amaurosis fugax and retinal vasculitis associated with methamphetamine inhalation.

A 26-year-old male drug abuser developed amaurosis fugax followed by retinal vasculitis in the right eye after nasal inhalation of methamphetamine. He gradually recovered, but required prolonged systemic corticosteroid therapy. We believe that the amaurosis fugax was due to drug-induced vasospasm and that the retinal vasculitis was a drug-induced hypersensitivity vasculitis.

Administration, Intranasal↗
PubMed1985

Patterns of herpes simplex keratitis in inbred mice.

The authors have investigated the course of herpes simplex type 1 (HSV) keratitis in three different inbred strains of mice infected with four different HSV isolates. Severity of ocular disease and mortality is dependent upon both the virus isolate and the host strain. In particular, the likelihood of progression from self-limited dendritic keratitis to severe necrotizing stromal keratitis varies markedly among the virus-host strain combinations tested. When mice from strains resistant to stromal disease are crossed with mice from strains susceptible to stromal disease, the F1 offspring are resistant, suggesting that the gene(s) controlling resistance is dominant. Corneal stromal keratocytes and embryo fibroblasts from inbred mice differ significantly in their ability to support the replication of HSV in vitro. HSV replicates more efficiently in vitro in keratocytes from mice susceptible to stromal keratitis than it does in keratocytes from mice resistant to stromal keratitis. These findings provide evidence in an animal model for both virus- and host-related mechanisms that determine susceptibility to stromal keratitis.

Animals↗
PubMed1984

Penetrating keratoplasty for exogenous Paecilomyces keratitis followed by postoperative endophthalmitis.

Three patients developed Paecilomyces lilacinus keratitis while being treated with topical corticosteroids and antibiotics. The first patient, a diabetic man, suffered superficial ocular trauma while being treated for recurrent anterior uveitis related to an iris-fixated intraocular lens. The second patient developed keratitis while being treated for anterior segment inflammation associated with herpes zoster ophthalmicus. The third patient, a woman with chronic lymphoma in remission, was receiving topical antibiotics and corticosteroids for a corneal transplant performed one year previously. All three patients underwent penetrating keratoplasty after progression to perforation or failure of medical therapy. Two eyes (cases 1 and 2) eventually required enucleation. The fungal isolates demonstrated in vitro resistance to amphotericin and natamycin with greater sensitivity to imidazole derivatives. Thus, we recommend prompt and prolonged topical treatment with miconazole or other imidazole derivatives along with avoidance of penetrating keratoplasty and corticosteroids.

Aged↗
PubMed1984

Penetrating keratoplasty in children.

Retrospectively studied were 91 patients, 14 years of age or less, who had 152 penetrating keratoplasties in 107 eyes, with an average follow-up of 30.1 months. Survival analysis showed the probability of obtaining a clear graft at one year to be 60 +/- 8% in 45 eyes with congenital opacities, 70 +/- 8% in 31 eyes with opacities from trauma and 73 +/- 8% in 31 eyes with acquired nontraumatic opacities. Most failures occurred during the first postoperative year and were characterized by the gradual loss of graft clarity from undetermined cause. Twenty-nine percent (10) of the 34 eyes with congenital corneal opacities in which vision could be measured had a most recent visual acuity better than 6/120 (20/400). Irreversible amblyopia, glaucoma, other structural abnormalities of the anterior segment and mental retardation complicated visual rehabilitation in the congenital group. In the post-traumatic group, vision was better than 6/120 (20/400) in 45% (13) of 29 eyes, being limited by vitreoretinal pathology, fibrous ingrowth, and optic nerve damage from glaucoma. Visual acuity in the acquired, nontraumatic group was better than 6/120 (20/400) in 67% (20) of 30 eyes. The percentage of patients achieving 6/12 (20/40) or better in the congenital, post-traumatic, and nontraumatic groups were 3% (1/34), 17% (5/29), and 47% (14/30), respectively. In the congenital group, only patients with posterior polymorphous dystrophy obtained a visual acuity of 6/30 (20/100) or better. Preoperative vascularization of the cornea, persistent epithelial defects, and performance of lensectomy-vitrectomy were factors most highly correlated with poor graft survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Results of penetrating keratoplasty for pseudophakic corneal edema with retention of intraocular lens.

We reviewed the records of 26 consecutive patients undergoing penetrating keratoplasty for pseudophakic corneal edema in which the original intraocular lens was retained. The average interval between lens implantation and penetrating keratoplasty was 31.5 months. Follow-up after keratoplasty ranged from 11 to 59 months, with an average of 24.5 months. Six patients had anterior chamber lenses; sixteen, iris or iridocapsular lenses; and four, posterior chamber lenses. A vitrectomy was performed in 14 (54%) patients. Of the 21 patients with clear grafts (80%), 8 (38%) had vision of 20/40 or better while 7 (33%) had acuities of 20/200 or worse. Visual acuity of 20/40 or better was attained by 3 of 4 (75%) patients with posterior chamber lenses but only 3 of 16 (19%) patients with iris-supported lenses. Cystoid macular edema was the principal cause of decreased acuity in 12 of the 13 patients with clear grafts and acuity less than 20/40. Angiographic confirmation was obtained in 7 of 12 patients. Overall, the results are similar to those reported for pseudophakic keratoplasty with intraocular lens removal. No adverse effect of retaining a securely fixated intraocular lens was demonstrated.

Cataract Extraction↗