ABSTRACT
Prominent radial iris blood vessels created small but definite pupillary notches in five children with persistent hyperplastic primary vitreous and persistence of the tunica vasculosa lentis. Detection of these abnormal iris vessels suggested the presence of persistent hyperplastic primary vitreous and related syndromes even when the diagnosis was obscured by the presence of an opaque lens. These vessels represented early developmental arrest and may have been associated with abnormal development of the macula and optic nerve. Surgical and amblyopia therapy, therefore, may not provide useful vision, and should be undertaken with caution.
Subject(s)
Eye Abnormalities , Iris/blood supply , Vitreous Body/abnormalities , Abnormalities, Multiple/diagnosis , Adult , Child, Preschool , Diagnosis, Differential , Eye Diseases/diagnosis , Eye Diseases/therapy , Eye Neoplasms/diagnosis , Female , Humans , Hyperplasia/pathology , Infant , Infant, Newborn , Male , Optic Disk/abnormalities , Pregnancy , Pregnancy Complications , Retinoblastoma/diagnosis , Syndrome , Vitreous Body/pathologyABSTRACT
Experiments with rabbits demonstrated no toxic effects on the retina after vitrectomy when the infusion fluid contained either 20 microgram/ml chloramphenicol saline, 10 microgram/ml amikacin saline, 10 microgram/ml tobramycin saline, or 10 microgram/ml clindamycin saline. We found abnormal electroretinograms and abnormal histologic findings in eyes receiving vitreous replacement with these same drugs in higher concentrations.
Subject(s)
Anti-Bacterial Agents/toxicity , Retina/drug effects , Sodium Chloride/administration & dosage , Vitreous Body/surgery , Amikacin/toxicity , Animals , Biocompatible Materials/toxicity , Chloramphenicol/toxicity , Clindamycin/toxicity , Rabbits , Tobramycin/toxicityABSTRACT
Various amounts of cryothermy were applied to the posterior pole of rabbit eyes to determine changes in retinal tissue and vasculature. Four consecutive freezing and refreezing applications of -60 degrees was the most effective technique for achieving central retinal vessel occlusion. Electron microscopic observations of sequentially sectioned occlusion. Electron microscopic observations of sequentially sectioned occluded vessels showed that the vessels were occluded by a platelet plug distally and packed erythrocytes proximally. Fibrin formation was not found in the occluded retinal vessels but was seen within platelet plugs in choroidal vessels. Because cryocoagulation simulates the normal physiologic means of coagulation more closely than other vessel occluding techniques, cryocoagulation of the primary retinal vessels is suggested as an experimental model for intravascular coagulation.
Subject(s)
Freezing , Retinal Vessels , Animals , Blood Coagulation , Cryosurgery , Disease Models, Animal , Hemostatic Techniques , Microscopy, Electron , Models, Biological , Rabbits , Retinal Vessels/ultrastructure , Thrombosis/etiologyABSTRACT
Intravitreal injection of 500 mcg of erythromycin as the gluceptate caused no toxicity to ocular structures. This dose maintained bacterial inhibitory concentrations in the vitreous for up to 24 hours. Consistent aqueous levels were not obtained with intravitreal injection. Intravitreal treatment of Staphylococcus aureus endophthalmitis was successful in 11 of 13 rabbit eyes compared to 2 of 13 treated with subconjunctival erythromycin.
Subject(s)
Endophthalmitis/drug therapy , Erythromycin/therapeutic use , Staphylococcal Infections/drug therapy , Animals , Erythromycin/administration & dosage , Erythromycin/toxicity , Injections , Rabbits , Staphylococcus aureus/isolation & purification , Vitreous BodyABSTRACT
The experimental data involving the use of 14 antibacterial and two antifungal agents have been used to establish a rationale for the management of human endophthalmitis. Twelve cases of endophthalmitis treated under our supervision have been described in detail. The eventual visual outcome is related to two factors: (1) time interval between diagnosis and institution of adequate therapy, and (2) the severity of the organism and its ability to produce exotoxins and proteolytic enzymes. Eleven of 12 cases were cured with the recommended dosages of gentamicin and dexamethasone (400 mcg and 360 mcg, respectively). Eight of the 12 patients retained useful vision of 20/200 or better.
Subject(s)
Bacterial Infections/drug therapy , Candidiasis/drug therapy , Endophthalmitis/drug therapy , Gentamicins/administration & dosage , Aged , Animals , Anti-Bacterial Agents/therapeutic use , Antifungal Agents/therapeutic use , Dexamethasone/administration & dosage , Dexamethasone/therapeutic use , Endophthalmitis/etiology , Gentamicins/therapeutic use , Humans , Injections , Male , Visual Acuity , Vitreous BodyABSTRACT
We wished to know if excision of artificially produced intravitreal vessels would cause bleeding and if the hemorrhage could be controlled by increasing the intraocular pressure. In 17 rabbit eyes, the distal end of several intravitreal blood vessels was excised and removed by the Peyman vitrophage. No significant bleeding occurred from the vessels in 13 eyes, and in the remaining four bleeding stopped after 30 seconds or less of increased intraocular pressure. In one month of observation after surgery, there was no evidence of delayed hemorrhage. Electron microscopy of several transected intravitreal vessels revealed that vessel constriction, platelets and fibrin strands contributed to the prevention of immediate and delayed hemorrhage.
Subject(s)
Retinal Vessels/surgery , Vitreous Body/surgery , Ammonium Chloride , Animals , Disease Models, Animal , Endothelium/ultrastructure , Erythrocytes/ultrastructure , Eye Diseases/chemically induced , Eye Diseases/pathology , Eye Diseases/surgery , Fibrin , Hemorrhage/etiology , Hemostasis , Intraocular Pressure , Microscopy, Electron , Postoperative Complications , Rabbits , Retinal Diseases/chemically induced , Retinal Diseases/pathology , Retinal Vessels/pathology , Time FactorsABSTRACT
A surgical approach to full-thickness eye wall biopsy is proposed as a method that may be applied to poorly understood diseases of the retina and choroid. An eye basket is sutured to the eye for stabilization, and two trephines mark an area to which diathermy is applied until penetration is achieved. The specimen is removed with fine forceps and scissors. A scleral homograft closes the defect. In ten rabbits, no eyes were lost and all ten retinas were intact. All biopsy specimens were suitable for histologic study.
Subject(s)
Choroid , Eye Diseases/diagnosis , Retinal Diseases/diagnosis , Animals , Biopsy/adverse effects , Biopsy/methods , Choroid/anatomy & histology , Choroid/surgery , Conjunctiva , Diathermy/adverse effects , Edema/etiology , Electroretinography , Hyperemia/etiology , Ophthalmoscopy , Rabbits , Retina/anatomy & histology , Retina/surgery , Sclera/anatomy & histology , Sclera/surgery , Sclera/transplantation , Transplantation, Autologous , TrephiningABSTRACT
Toxicity of gentamicin and its use in the treatment of experimentally induced Pseudomonas aeruginosa endophthalmitis were studied in the postoperative aphakic eye. The retinal toxicity of intravitreal gentamicin was different from toxicity in the intact eye and varied with the method of injection. Successful prophylaxis of induced postoperative infection was obtained with an intravitreal injection of 30 mu-g of gentamicin but not with sub-Tenon's administration of gentamicin. Treatment for progressive endophthalmitis was effective with high dose (200 mu-g) gentamicin alone, or a combination of low-dose (30 mu-g) gentamicin with topical and systemic gentamicin. Either sub-conjunctival and systemic gentamicin or low-dose gentamicin alone was ineffective once endophthalmitis was in progress. Although vitrectomy removed abscess products, it failed in this experiment to provide better results than the other modes of therapy.
