RESUMO
Benzalkonium chloride [BAC] is a commonly used preservative in topical ophthalmic preparations. It is a cytotoxic compound. The mechanism of action involves dissociation of bilaminar plasma membrane and its tendency to dissolve cholesterol, phospholipids and the proteins in the cell membrane. The indiscriminate use of eye drops containing BAC, quackery and self-medication may increase the incidence of corneal disorders particularly in those having a pre-existing corneal pathology
Objective: The present in vivo study was carried out to investigate the effects of BAC ons corneal stroma
Methods: Two different concentrations [0.02% and 0.0075%] of BAC solution comparable to those present in the commercially available eye drops were prepared in isotonic saline. Right eye of each animal was treated with BAC solution while left eye of the same animal served as a control treated with normal saline alone
Results: The analysis of the results revealed significant [p<0.05] histological changes in the corneal stroma
Conclusion: This study has provided the convincing evidence that BAC is toxic to the corneal stroma and is a factor contributing towards visual impairment
RESUMO
Inter-vertebral disc is the largest avascular structure in human body, which is primarily a load bearing and stabilizing unit of the human spine. Degenerative disorders and disc herniation causes proliferation or in growth of new blood vessels in this structure. Lumbar disc herniated tissues were studied microscopically in comparison with the cadaveric lumbar disc tissue, to evaluate the changes particularly the formation of new blood vessels. It was a case control study in which 45 lumbar herniated disc tissues [L[4] - L[5] and L[5] - S[1]] and 45 dissected, fresh cadaveric disc tissues of same level and almost of same age groups were collected and in reference to age were divided into groups. Both sets of tissues were processed, sectioned and stained with Hemotoxyllin / Eosin, to observe the architecture of annuli fibrosis and nuclei pulposus parts of disc and the micro-vessels under light microscope. Cadaveric discs, group A, B and C compared with herniated discs A[1], B[1] and C[1], Annuli fibrosi in herniated discs [A[1], B[1], and C[1]] showed significant reduction of cells, disorganized lamellar pattern of collagen, formation of cysts, clefts and numerous new micro-vessels as compared to fresh cadaveric disc tissues [A, B and C]. Disc degeneration and herniation results in the formation of micro-vessels which may not only serve as source of nutrients but also contribute in the healing process of discal tears
RESUMO
Purpose: To determine astrogliosis in optic nerve of rabbit induced by ethambutol
Materials and Methods: Ten, New Zealand white, albino rabbits of either sex, 6-12 months old; weighing 1- 2 kg were randomly divided into two group comprising five animals in each. Group A served as control, while Group B was given ethambutol 100 mg/kg/day for four weeks. At the end of experimental period, each animal was sacrificed by using chloroform and both optic nerves were dissected out, preserved and processed; in this way, twenty optic nerve specimens Maximum stone size included in our study was 3 cm. All patients included in our study were treated by rigid URS and stone fragmentation with Pneumatic Lithoclast. [ten for each group] were collected from ten albino rabbits
Results: Mean number of astrocytes, calculated in group B was 27.94 +/- 2.94, that was significantly increased from those in group A, showing mean number of astrocytes as 09.66 +/- 2.16 [p value = 0.001]
Conclusion: Ethambutol, in toxic doses, induces the proliferation of astrocytes in optic nerve, a part of astrogliosis, indicating the repair process in damaged optic nerve