Retnal Toxicty of Intravitreal Tissue Plasminogen Activator with C3F8 Injection in Rabbit Eyes

PURPOSE: To determine the concentration at which a mixed injection of tissue plasminogen activator (tPA) and C3F8 gas is toxic, we studied the histopathological changes in the rabbit retina. METHODS: Only tPA was injected into the right vitreous cavities of 18 normal pigmented rabbits at doses of 25 micro gram/0.1mL, 50 micro gram/0.1mL, and 100 micro gram/0.1mL, 6 rabbits per dosage. In the same rabbits, tPA and C3F8 (0.2cc) were simultaneously injected into the left vitreous cavities at doses of 25 micro gram/0.1mL, 50 micro gram/0.1mL, and 100 micro gram/0.1mL. All of the eyes were examined by slit lamp biomicroscopy and indirect ophthalmoscopy at 5, 10, and 15 days after the injection, and then they were enucleated for histopathological evaluation. RESULTS: Retinal pigmentary alterations were centered around the injection site 3 days postoperatively in the eyes receiving doses of 50 micro gram/0.1mL or greater. On light microscopy(LM), the involved areas showed vacuolization in the photoreceptor elements and the inner nuclear layer(INL) at a dose of 25 micro gram/0.1mL at postoperative 5 days and the vacuolar changes disappeared at postoperative 15 days. But at doses of 50 micro gram/0.1mL or greater, loss, contracture, and vacuolization of the photoreceptor outer segment (POS) and vacuolization of INL were noted at postoperative 15 days. On LM, at a dose of 25 micro gram/0.1mL, the involved areas showed vacuolization in POS and mitochondrial swelling of the photoreceptor inner segment (PIS) at postoperative 5 days. The mitochondrial swelling of PIS disappeared at postoperative 15 days. However, at doses of 50 micro gram/0.1mL or greater, loss and contracture of POS and mitochondrial swelling of PIS were noted at postoperative 15 days. The retinal damage from simultaneous injection of tPA and C3F8 at doses of 25, and 50 micro gram/0.1mL was equal to or less than that of only tPA injection, whereas at a doses of 100 micro gram/0.1mL the damage was greater. CONCLUSIONS: At doses of 50 micro gram/0.1mL or greater, irreVersible retinal toxicity was noted histopathologically in rabbit eyes. At doses of 25, and 50 micro gram/0.1mL, the degree of retianl damage did not seem to be affected by whether C3F8 was injected concomitantly or not.

Analysis of Blood Constituents in Korean Cataract Patients

To estimate change of blood constituents in cataract patients, the authors retrospectively reviewed medical records of catatract and non-cataract patients.We selected 199 pairs of cataract and non-cataract patients matched in age and sex.We compared the presence of diabetes, hepatitis B antigen and hepatitis C antibody, also other blood chemistry values between cataract and non-cataract patients group and also between cortical and noncortical patients group. Results are as follows:In cataract patients group, ALP (alkaline phosphatase) albumin/total protein-albumin ratio and K (potassium)were higher, and Na (sodium), total biilrubin and total protein were lower than in non-cataract patients.And in cortical cataract patients, AST (aspartate aminotransferase), BUN (Blood Urea Nitrogen), total calcium, Cr (creatinine), K and Cl (chloride) were higher and albumin/total protein-albumin ratio was lower than in noncortical cataract patietns.

A Case of Progressive Proliferative Retinopathy in Incontinentia Pigmenti after Photocoagulation

A 11-days-old female was diagnosed as incontinentia pigmenti by skin biopsy was referred for ophthalmological examination.The fundus of the right eye showed vacularization only in the posteroir pole and neovascularization in the junctional area between vascular and avascula retina.Systemic evaluation revealed no associated abnormality.At 22 days of age, we ablated avascular retina with indirect diode laser photocoagulation under general anesthesia. Despite extensive 360 degree photocoagulation, fibrovascular proliferation was found to extend into vitreous cavity from optic disc 3 weeks after photocoagulation.

The Effect of Topical Mitomycin-C on the Patency of Internal Nasal Ostium of the Experimental Antrorhinostomy in Rabbits

The purpose of this study is to evaluate the effect of topical mitomycin C as an adjuvant therapeutic agent on prevention of internal nasal ostium obstruction in experimental rabbit dacryocystorhinostomy model. Forty-two rabbits received an osteotomy between maxillary antrum and nasal cavity. Topical mitomycin C solution had been instilled postoperatively for five days. The diameter of remaining ostium was measured and histopathologic study was performed. At 8 postoperative weeks, the ostial diameter of mitomycin C treated group was larger than that of control group. Nasal mucosa of control group showed active fibroblast and abundunt collagen fibers. But nasal mucosa of MMC group showed degenerated fibroblast and scanty collagen fibers. In conclusion, these results suggest that topical MMC eyedrop may be used as an effective adjuvant in preventing fibrous obstruction of internal nasal ostium in dacryocystorhinostomy.

The Effect of Mitomycin-C Eyedrop on Prevention of Internal Ostium Obstruction after Endonasal Dacryocystorhinostomy

The authors evaluated the effect of topical mitomycin-C on the prevention of dacryocystorhinostomy internal ostium obstruction as antifibroblastic adjuvant. Topical 0.02% mitomycin-C(MMC) eyedrop was applied postoperatively to conjunctival sac of 75 patients who underwent endoscopic dacryocystorhinostomy-MMC group. MMC was instilled twice a day from postoperative 1 day for 7 days and from postoperative 4th week for 7 days. Properly matched another 75 patients without postoperative adjuvant MMC were compared with MMC goup regarding endoscopic findings, patency rates and other eyedrop complications. The internal ostium were patent in 85% in MMC group, and 77% in MMC and control group, respectively. Endoscopic examination of internal ostium showed mean final diameter of 3.4mm in MMC group and 2.5mm in control. There were no significant complications in MMC group except delayed epithelialization of nasal mucosa which had no relationship with surgical outcome.