OBJECTIVETo evaluate the experimental induction of posterior vitreous detachment (PVD) by intravitreous injection of hyaluronidase and perfluoroethane (C(2)F(6)).

METHODSFifteen rabbits (30 eyes) were divided into 3 experimental groups,the contralateral eyes in same animals served as the controls. Eyes in group A and B were received two vitreous injections of 15 IU of hyaluronidase at an interval of 5 d. The eyes in group C and all control eyes were injected with balanced salt solution (BSS). Seven days after injection, the experimental eyes in group A and C were received 0.5 ml of Fifteen rabbits (30 eyes) were divided into 3 experimental groups, the contralateral eyes in same animals served as the controls. Eyes in group A and B were received two vitreous injections of 15 IU of hyaluronidase at an interval of 5 d. The eyes in group C and all control eyes were injected with balanced salt solution (BSS). Seven days after injection,the experimental eyes in group A and C were received 0.5 ml of C(2)F(6) injection. The ocular and retinal signs were examined for 8 following weeks and then killed for histological examination.

RESULTFive eyes in group A (100.0%) showed complete separation of the vitreous cortex from the retina (PVD), three eyes in group B(60.0%) showed partial PVD, and no PVD was detected in group C and all control eyes. On electroretinogram no significant difference was found in amplitude and latency of a-(or b-) wave in both experimental and control eyes, between before and after experiments. No evidence of ocular or retinal toxicity was revealed by light or scanning electronic microscopy in all eyes.

CONCLUSIONVitreous injection of hyaluronidase combined with perfluoroethane, as a safety method, can induce posterior vitreous detachment without mechanical vitrectomy.

Animals ; Electroretinography ; Female ; Fluorocarbons ; pharmacology ; Hyaluronoglucosaminidase ; pharmacology ; Male ; Ophthalmologic Surgical Procedures ; methods ; Rabbits ; Vitreous Body ; drug effects ; surgery ; ultrastructure ; Vitreous Detachment ; etiology

PURPOSE: To evaluate the usefulness of OCT retinal mapping in determining the configuration of a vitreomacular adhesion and selecting a meridian for entry into the subhyaloid space in patients with vitreomacular traction syndrome. METHODS: Six consecutive patients (6 eyes) with vitreomacular traction syndrome underwent vitrectomy with peeling of posterior hyaloid. Ocular coherence tomography (OCT) retinal mapping was performed preoperatively. Access to the subhyaloid space was made by creating an opening with a 25 gauge needle at a location where the detached posterior hyaloid membrane was farthest from the retinal surface. The location was selected based on six preoperative meridional OCT scans. The posterior hyaloid was then gently peeled off in a circular fashion around the fovea with a micropick. Visual acuity and foveal thicknesses were measured before the operation and 3 months afterwards. RESULTS: After the operation, visual acuity improved and central macular thicknesses were reduced significantly in all six patients. The best corrected visual acuity improved from 0.4 to 0.75 with a mean increase by 3.5 lines on a Snellen chart 3 months after the operation. The mean foveal thickness was reduced from 406 micrometer to 241 micrometer. The restoration of foveal pit was observed in five patients. Neither intraoperative nor postoperative complications were observed during the follow up period. CONCLUSIONS: An OCT retinal mapping program is a valuable diagnostic tool in understanding the configuration of vitreomacular adhesion and planning the surgical approach for operating on vitreomacular traction syndrome.
Aged ; Eye Diseases/diagnosis/etiology/*surgery ; Female ; Humans ; Male ; Middle Aged ; Retinal Diseases/diagnosis/etiology/*surgery ; Syndrome ; Tissue Adhesions/etiology/surgery ; *Tomography, Optical Coherence ; Visual Acuity ; Vitrectomy/*methods ; Vitreous Body/pathology/*surgery ; Vitreous Detachment/complications

Cryotherapy is implicated for inducing or aggravating proliferative vitreoretinopathy (PVR) by releasing retinal pigment epithelial (RPE) cells. These are based on the fact that PVR rarely occurs in a non-operated eye, and many of the PVR patients have received cryotherapy during surgery. Nonetheless, eyes with diathermy also developed PVR, and although there have been many experiments, the effect of cryotherapy on inducing PVR has not been proven experimentally in the living eye. We made retinal tears in living rabbit eyes, and applied cryotherapy on one eye of each rabbit. The result was compared histologically with the contralateral noncryothermized control eye. There was no statistically significant difference between the two groups concerning the migration of RPE, and the proliferation of RPE. Although the formation of an epiretinal membrane was more obvious in the cryothermized group, the difference was not statistically significant.
Animals ; Cell Division ; *Cryosurgery/adverse effects ; Rabbits ; Retinal Detachment/*pathology ; Retinal Perforations/*pathology ; Vitreous Body/*pathology/surgery

This report presents the effectiveness of 25-gauge Transconjunctival Sutureless Vitrectomy (TSV) for various vitreoretinal disorders. We performed vitreoretinal surgery on 6 patients using 25-gauge TSV. Minimal or no leakage of intraocular fluid or gas was observed at the entry site. No case required a suture to close the conjunctival or scleral opening site, and no complications resulted from the opening site. Median preoperative visual acuity was 0.04 and median postoperative best corrected visual acuity (BCVA) with a mean follow-up of 12 weeks, was 0.45. Median preoperative intraocular pressure was 12.67mmHg, and median intraocular pressure on the first postoperative day was 15.67 mmHg. Because transconjunctival sutureless surgery is minimally invasive, it increases the efficiency of vitrectomy, hastens postoperative recovery, and improves outcomes due to the simplified surgical procedure. We feel that the adoption of the 25-gauge TSV would lead to improved patient comfort, care, and management.
Adult ; Aged ; Child, Preschool ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Retina/*surgery ; Retinal Diseases/*surgery ; Retrospective Studies ; Visual Acuity ; Vitrectomy/*instrumentation/*methods ; Vitreous Body/*surgery

To determine surgical results and predictive factors of final visual acuity, a total of 30 eyes in 30 uveitis patients who underwent vitreous surgery including pars plana vitrectomy were followed for at least 6 months and various preoperative factors and postoperative results were analyzed. Our surgical indications were vitreous opacity, traction retinal detachment, combined rhegmatogenous-traction detachment. Preoperatively detached retina was finally reattached in 15 (83.3%) of 18 eyes. Final visual acuity improved in 19 (63.3%) of 30 eyes, but decreased in 3 eyes compared with the initial acuity. Cystoid macular edema was the main cause of poor visual acuity after surgery. Eyes with good final visual acuity showed relatively normal electroretinograms before surgery, but the relationship between them was not statistically significant. Duration of postoperative inflammation affected final visual acuity significantly. These results suggest that chronic uveitis patients with vitreoretinal complications can be managed by vitreous surgery with good anatomic and functional results.
Adolescent ; Adult ; Child ; Chronic Disease ; Eye Diseases/etiology/surgery ; Female ; Humans ; Male ; Middle Aged ; Prognosis ; Retinal Diseases/etiology/*surgery ; Uveitis/*complications ; Visual Acuity ; *Vitrectomy ; Vitreous Body/*surgery

To determine surgical results and predictive factors of final visual acuity, a total of 30 eyes in 30 uveitis patients who underwent vitreous surgery including pars plana vitrectomy were followed for at least 6 months and various preoperative factors and postoperative results were analyzed. Our surgical indications were vitreous opacity, traction retinal detachment, combined rhegmatogenous-traction detachment. Preoperatively detached retina was finally reattached in 15 (83.3%) of 18 eyes. Final visual acuity improved in 19 (63.3%) of 30 eyes, but decreased in 3 eyes compared with the initial acuity. Cystoid macular edema was the main cause of poor visual acuity after surgery. Eyes with good final visual acuity showed relatively normal electroretinograms before surgery, but the relationship between them was not statistically significant. Duration of postoperative inflammation affected final visual acuity significantly. These results suggest that chronic uveitis patients with vitreoretinal complications can be managed by vitreous surgery with good anatomic and functional results.
Adolescent ; Adult ; Child ; Chronic Disease ; Eye Diseases/etiology/surgery ; Female ; Humans ; Male ; Middle Aged ; Prognosis ; Retinal Diseases/etiology/*surgery ; Uveitis/*complications ; Visual Acuity ; *Vitrectomy ; Vitreous Body/*surgery

Hereditary vitreous degeneration muddy is rare in clinic. Here we report ten cases (thirteen eyes) of hereditary vitreous degeneration muddy from two families. All patients presented with vitreous opacity, and the textures appeared tough and tensile. Two cases had concurrent detachment of rhegmatogenous retina. HE staining showed red changeableness, and methyl violet staining appeared purple. All patients received vitrectomy with traditional Chinese medicine treatment, and got satisfactory efficacy.
Eye Diseases, Hereditary ; diagnosis ; pathology ; surgery ; therapy ; Female ; Humans ; Male ; Medicine, Chinese Traditional ; Retinal Detachment ; diagnosis ; surgery ; Vitrectomy ; Vitreous Body ; pathology ; surgery

Examination of a 36-year-old man with naked visual acuity of 20/20 revealed a floating, conspicuous cyst of Cysticercus cellulosae in the vitreous cavity of the right eye. A vitreous traction band from the vitreous base and the optic disc was connected to the lodging bulb of the cyst. In the superonasal area, an ovoid retinal break surrounded by a white retinal lesion with two elliptical retinal hemorrhages was found, and this seems to be the previous lodging site of the cyst. A pars plana vitrectomy was performed to remove the parasite, and laser photocoagulation was carried out around the retinal break. Four months after the operation, the patient was satisfied with naked visual acuity of 25/20 without any complication in the affected eye.
Adult ; Animals ; Cysticercosis/*diagnosis/physiopathology/surgery ; Cysticercus/*isolation & purification ; Eye Diseases/diagnosis ; Eye Infections, Parasitic/*diagnosis/physiopathology/surgery ; Humans ; Laser Coagulation ; Male ; Retinal Hemorrhage/etiology/surgery ; Retinal Perforations/etiology/surgery ; Visual Acuity ; Vitrectomy ; Vitreous Body/*parasitology/surgery

Iris neovascularization was produced in rabbits by hypotony following repeated aspiration of the vitreous. The hypotony was produced after 0.3 ml of vitreous fluid was aspirated using a 25-gauge needle through the pars plana of 10 rabbits. For the histochemical study, horseradish peroxidase(HRP) was injected through the ear lobe vein. After fixation of the iris tissue, the tissue was treated with diaminobenzidine and examined with both light microscopy and transmission electron microscopy. The newly-formed vessel was abundant, particularly on the upper stroma of the iris. The new vessel formation was evident due to the proliferation of endothelial cells, which may have been derived from preexisting iris vessels. The endothelial cells of the newly-formed vessels revealed prominent villous processes into the vascular lumen, formation of the marginal flap, numerous fenestrations in the endothelial junction, and reaction product onto extravascular space by the cytochemical electron microscopy. These results suggest that hypotony in the rabbit produces the disruption of the blood-iris barrier and the balance between angiogenesis-antiangiogenesis modulation.
Animals ; Biological Transport, Active ; Disease Models, Animal ; Horseradish Peroxidase/diagnostic use ; Iris/*blood supply/*ultrastructure ; Iritis/*pathology ; Neovascularization, Pathologic/*pathology ; Rabbits ; Vitreous Body/surgery

Eighteen eyes with vitreous strands adherent to the corneoscleral wounds of previous cataract surgery were treated with neodymium: YAG laser to lyse those strands. Twelve eyes were treated for management of cystoid macular edema (CME group); six eyes were treated for prophylaxis of possible CME (prophylactic group). In the CME group, visual acuity improved two or more lines in nine eyes (75.0%), and seven eyes had a post laser visual acuity of 0.5 or better (One eye had a pre-treatment visual acuity of 0.5 or better). In the prophylactic group, visual acuity was either maintained at the pre-treatment visual acuity of 0.5 or better. In the prophylactic group, visual acuity was either maintained at the pre-treatment level or improved in five eyes (83.3%) 18 months later following laser treatment. This procedure was complicated by retinal detachment in one case and the elevation of intraocular pressure over 10 mmHg in another case.
Adult ; Aged ; Aged, 80 and over ; Cataract Extraction/adverse effects ; Eye Diseases/etiology/surgery ; Female ; Humans ; *Laser Therapy ; Macular Edema/prevention & control/*surgery ; Male ; Middle Aged ; Visual Acuity ; Vitreous Body/*surgery