Oxidative stress of intracameral lidocaine and levobupivacaine on ocular tissues.

BACKGROUND: To investigate the biochemical changes on the oxidant/antioxidant balance in corneal and lens tissues in rabbits, and to determine the relative corneal endothelial toxicities following the injection of intracameral anaesthetic agents: levobupivacaine 0.5% or lidocaine 2%. METHODS: The experiment was conducted using New Zealand rabbits. The rabbits were randomly divided into three experimental groups. Twenty eyes received injections of 0.2 ml of one of the two anaesthetic preparations and 10 control eyes received injections of 0.2 ml balanced salt solution. Corneal thickness and clarity were measured before and 3 and 6 h after surgery. Anterior chamber reaction was evaluated 1, 3 and 6 h after surgery. In corneal and lens tissues, malondialdehyde and total thiol levels were measured using spectrophotometric methods. RESULTS: Levobupivacaine 0.5% caused corneal thickening, oedema and anterior chamber reaction (p<0.001). There were no biochemical changes in the levobupivacaine group (p>0.05). No change was observed in the corneal thickness, oedema and anterior chamber reactions, whereas the level of malondialdehyde significantly increased in corneal and lens tissues (p<0.001, p=0.015, respectively), and the level of total thiol significantly decreased in the lens tissue in the lidocaine 2% group (p<0.001). CONCLUSIONS: The results of this study suggest that levobupivacaine 0.5% has an immediate toxicity on corneal endothelium. Lidocaine 2% causes oxidative damage on corneal and lens tissues. Surgeons should not use repetitive and high doses of intracameral lidocaine in the presence of corneal pathology during cataract surgery.

Tear function and ocular surface changes in multinodular goiter patients.

AIMS: To evaluate preoperative and postoperative conjunctival surface changes in multinodular goiter (MNG) patients and to compare their results with healthy control subjects. METHODS: Twenty MNG patients who had undergone near total thyroidectomy were evaluated pre- and postoperatively at the end of the 3rd month and the 1st year by performing tear function tests and conjunctival impression cytologic analysis. These results were compared with the results of 15 healthy volunteers. RESULTS: When preoperative and postoperative tear function parameters were compared, the mean Schirmer test value and BUT value were decreased, the mean Rose Bengal staining score was increased during the postoperative period. These differences were statistically significant at the end of the 1st year (p < 0.001). The average goblet cell density of the MNG patients decreased significantly during the postoperative period when compared with the preoperative values (p < 0.001). All these findings of the MNG cases were significantly different from the results of the control group both before and after the operation. CONCLUSION: Tear function tests and the impression cytology findings of the MNG cases were statistically different from the results of the control group during the pre- and postoperative period. We recommend postoperative follow-up of these patients for ocular surface changes.

Results of therapeutic penetrating keratoplasty.

PURPOSE: By a retrospective study of patients in the Ankara Hospital Eye Clinic, to determine the anatomical and visual results of therapeutic penetrating keratoplasty (PK) and its role in the management of corneal disease. METHODS: Therapeutic PK was performed in 36 patients (37 eyes) who had corneal perforation due to corneal disease (23 eyes) or eyes in which perforation was imminent (14 eyes). Initial indications for grafting were nonperforated descemetocele without inflammation (six eyes, 16.2%); nonperforated bacterial corneal ulcer (five eyes, 13.5%); nonperforated herpetic keratitis with active stromal inflammation (two eyes, 5.4%); acanthamoeba keratitis (one eye, 2.7%); perforation due to herpetic keratitis (13 eyes, 35.2%); perforation due to persistent epithelial defect (8 eyes, 21.6%); or perforation due to bacterial corneal ulcer (two eyes; 5.4%). The results were evaluated for each of the following criteria: anatomical integrity of the eye, cure of the disease, complications, graft clarity, and visual acuity. RESULTS: Anatomical integrity was achieved in 21 of the 23 eyes (91.3%) perforated from corneal disease. Therapeutic PK cured the disease in all bacterial keratitis cases. The proportion of clear grafts was 60.9% in the 23 eyes perforated from corneal disease, and 57.1% in the 14 eyes in which perforation was imminent. Fifteen eyes (40.5%) obtained a final visual acuity of 20/100 or better; five of these eyes were not yet perforated before the PK. CONCLUSIONS: Therapeutic PK is effective in the management of the eye with active uncontrolled infection or perforation from corneal disease. Approximately half of our patients maintained a clear graft at the last visit. Without therapeutic surgery, these eyes would have been lost.