Biomedical subjects

J D Gottsch

Publications and source records attributed to J D Gottsch.

At least 73 records · Page 4Linked to original sources

PubMed1989

Managing posterior pressure during pseudophakic keratoplasty.

Positive vitreous pressure during penetrating keratoplasty can be difficult to manage. Despite preventive measures, positive vitreous pressure may occur and appropriate intervention is necessary to prevent serious complications. We describe a technique that may be used intraoperatively to restore a formed anterior segment and to prevent vitreous loss when persistent positive vitreous pressure occurs, while attempting to implant a pseudophakos. A 27-gauge needle, passed across the anterior chamber from limbus to limbus, just anterior to the iris, will stabilize the pseudophakos, restore the anterior chamber depth, and allow donor-tissue suturing.

Cataract Extraction↗

PubMed1989

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.

Animals↗

PubMed1989

Contact lenses for visual rehabilitation after corneal laceration repair.

A contact lens fitting was tried after corneal laceration repair in 26 eyes. The mean patient age was 25 years; 22 eyes were aphakic and there were 23 males. Many patients had been referred for penetrating keratoplasty. Intact sutures in 13 eyes did not hinder contact lens fitting which was performed within 6 months in 12 cases. A contact lens was fit and successfully worn in 21 eyes (81%) and was fit in the remaining five patients, but not worn because of suboptimal vision (4 eyes) or an unsatisfactory fit (1 eye). Success rates were higher for small, peripheral lesions and in younger patients. Visual acuity was at least 20/30 in 12 patients and follow-up averaged 10.1 months. A contact lens can usually be fit after corneal lacerations, despite aphakia, with good visual results, thereby avoiding penetrating keratoplasty and intraocular lens implantation.

Adolescent↗

PubMed1989

Dextran efflux from McCarey-Kaufman-stored corneas as measured by nuclear magnetic resonance.

Dextran, a high molecular weight polymer of glucose, is used as an osmotic agent in McCarey-Kaufman (MK) (corneal storage) medium. It has been proposed that Dextran may cause deleterious effects on living cells either by high molecular weight toxicity or by the induction of an immunological reaction against transplanted tissues. Prolonged retention of Dextran in transplanted corneas, therefore, may produce deleterious side effects. The efflux of Dextran from MK-stored human corneas was monitored by transferring corneas to 2 ml of fresh Krebs Ringer bicarbonate solution (BSS) containing 5.5 mM 1-13C-labeled glucose at approximately 1 h intervals for 1-24 h. Chemical shifts of 98.7, 74.5, 72.5, 71.2, 70.6, and 66.5 ppm were found for the naturally abundant 13C NMR spectrum of 40,000 molecular weight Dextran. Peak heights for the 70.6 ppm Dextran chemical shift were measured and plotted against total wash time to determine the slope for Dextran efflux from each cornea. The results of this study suggest that all of the Dextran absorbed into human corneas stored for up to 2 weeks in MK medium is eluted in about 19 h and that the rate of Dextran efflux is unaffected by donor age, time of storage in MK, or corneal viability.

Adult↗

PubMed1989

Complications of cataract extraction with intraocular lens implantation.

Due to continued improvement in lens design, lens manufacturing, and surgical technique, the incidence of complications of cataract surgery with intraocular lens (IOL) implantation have decreased in recent years. Complications may be categorized into operative and postoperative, both early and late onset. Operative complications include posterior capsule rupture with or without vitreous loss, loss of all or part of the lens nucleus, iris damage, and stripping of Descemet's membrane. Early postoperative complications include pupillary block, hyphema, elevation of the intraocular pressure associated with the use of viscoelastic substances, persistent uveitis with or without hypopyon, and endophthalmitis. Late postoperative complications include IOL malposition, secondary glaucoma, cystoid macular edema, retinal detachment, and pseudophakic bullous keratopathy.

Cataract Extraction↗

PubMed1989

Lamellar keratectomy and repeat epikeratoplasty following failed epikeratoplasty. A clinicopathologic report.

Although epikeratoplasty (epikeratophakia) for aphakia in children has achieved a high degree of success, there remains a significant incidence of complications, some of which may result in removal of the lenticule. We report a 2-year-old child in whom epikeratoplasty was followed by an acute suppurative keratitis, necessitating removal of the epikeratoplasty lenticule. The recipient bed remained scarred following removal of the lenticule with anterior stomal fibrosis, which precluded good vision. We were able to avoid a penetrating keratoplasty by performing a superficial lamellar keratoplasty with a repeat epikeratoplasty that has remained clear.

Child, Preschool↗

PubMed1988

Use of collagen corneal shields in the treatment of bacterial keratitis.

We used an animal model of Pseudomonas keratitis to compare treatment by topical tobramycin with and without the presence of a commercially available collagen corneal shield. Pilot studies showed a significant, 30-fold increase in penetration of tobramycin into the anterior chamber in eyes with a collagen shield in place. Twenty albino rabbit eyes were inoculated with P. aeruginosa to produce stromal keratitis. After 12 hours of topical tobramycin dosing, eyes with a collagen corneal shield in place had a statistically significant (P less than .01) decrease in colony forming unit counts in comparison to treated eyes without a shield and control eyes.

Animals↗

PubMed1988

Topical imipenem therapy of aminoglycoside-resistant Pseudomonas keratitis in rabbits.

We used a rabbit model of bacterial keratitis to assess in vivo efficacy of topical imipenem, a highly potent beta-lactam antibiotic with an unusually broad spectrum of activity, including aminoglycoside-resistant Pseudomonas aeruginosa. Albino rabbits received intrastromal injections of 5 x 10(2) organisms of an aminoglycoside-resistant strain of P. aeruginosa. At five hours postinoculation, imipenem (5 mg/ml) therapy was initiated using one drop per 30 minutes for 12 hours. Corneal tissue was then excised for colony forming unit counts. Imipenem was highly effective in reducing colony forming unit counts to zero in comparison to 4.1 x 10(5) organisms for untreated controls. A second regimen beginning 24 hours postinoculation of one drop per hour for 24 hours was also successful in significantly reducing colony forming units vs controls (P less than .05). These data suggest that topical imipenem may have clinical applicability in the treatment of P. aeruginosa keratitis.

Administration, Topical↗

PubMed1988

Corneal graft survival in the cat with prolonged preservation in McCarey-Kaufman and K-Sol media.

The effects of extended preservation on transplanted corneas were investigated using McCarey-Kaufman (M-K) and K-Sol media. Cat corneas were preserved in either M-K or K-Sol at 4 degrees C for 5, 10, 15, or 20 days and were subsequently transplanted. Postoperatively, transplants were observed via slit-lamp biomicroscopy and pachymetry and at postmortem examination by light and scanning electron microscopy. In this study, we found no difference in the corneal graft clarity, thickness, endothelial cell count, or morphologic features of corneal transplants preserved in either M-K or K-Sol media. Storage for more than ten days in either M-K or K-Sol media led to primary graft failure. This study demonstrated equivalent results in corneal preservation using either M-K or K-Sol media. The development of better preservation media may require changes in essential nutrients rather than changes in osmotic constituents.

Animals↗

PubMed1988

Topical ciprofloxacin treatment of Pseudomonas keratitis in rabbits.

Ciprofloxacin is a new quinolone antibiotic that is highly active in vitro against Pseudomonas aeruginosa. A rabbit model of bacterial keratitis was used to assess the in vivo efficacy of topical ciprofloxacin. Albino rabbits received intrastromal injections of 5 X 10(2) aminoglycoside-resistant P aeruginosa organisms. At five hours after inoculation, ciprofloxacin (3 mg/mL) therapy was initiated (one drop every 30 minutes for 12 hours). Corneal tissue was then excised for bacterial colony counts. No organisms were recovered from ciprofloxacin-treated eyes, compared with an average of 3.1 X 10(7) organisms per milliliter recovered from untreated controls. This model suggests that topical ciprofloxacin may be clinically useful in the treatment of aminoglycoside-resistant P aeruginosa keratitis.

Administration, Topical↗

PubMed1988

Methicillin-resistant Staphylococcus epidermidis keratitis treated with vancomycin.

Staphylococcus epidermidis accounts for nearly one third of all cases of bacterial keratitis in certain geographic areas. Recently, the sensitivity of this organism has changed dramatically so that nearly half of nosocomially acquired systemic S epidermidis infections are resistant to methicillin sodium, cephalosporins, and aminoglycosides. Methicillin-resistant and gentamicin sulfate-resistant S epidermidis causing infectious blepharoconjunctivitis and endophthalmitis has previously been reported. Two cases of methicillin- and gentamicin-resistant S epidermidis keratitis occurred that were treated successfully with topical vancomycin hydrochloride.

Adult↗

PubMed1988

The efficacy and safety of combined trabeculectomy, cataract extraction, and intraocular lens implantation.

The safety and efficacy of combined trabeculectomy, extracapsular cataract extraction (ECCE), and posterior chamber intraocular lens (PC IOL) implantation were evaluated by retrospectively analyzing 108 consecutive operations. Postoperatively, 89% of eyes achieved 20/40 or better visual acuity when preoperative macular and optic nerve diseases were excluded. Mean follow-up was 16.8 months. Intraocular pressure (IOP) control (less than or equal to 21 mmHg) was achieved in 92% of eyes; 57% required no medications. Capsulotomy (20%) and transient hyphema (15%) occurred significantly more often (P less than 0.001) than in a comparison group. These results suggest that the combined procedure gives excellent visual rehabilitation and IOP control in the majority of patients included in this analysis.

Aged↗

PubMed1988

Use of collagen corneal shields versus soft contact lenses to enhance penetration of topical tobramycin.

We compared the corneal penetration in rabbits of topical tobramycin in the presence of collagen corneal shields and bandage soft contact lenses. A collagen corneal shield was placed on six albino rabbit eyes, while therapeutic soft contact lenses (61.4% poly-2-hydroxyethyl-methacrylate/38.6% water) were placed on six eyes. Four control eyes received no shield or contact lens. Topical tobramycin was applied to all 16 eyes every five minutes for six doses. Samples of aqueous humor were removed at 15 and 60 minutes following the last dose. Collagen corneal shields allowed a significant (P less than .05) increase in tobramycin penetration into the anterior chamber at 60 minutes compared with hydrophilic soft contact lenses or controls.

Administration, Topical↗

PubMed1988

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.

Alanine↗

PubMed1988