Corneal lipid changes after reodymium: YAG laser capsulotomy: [an experimental study]

Neodymium: YAG laser is used primarily in the management of posterior capsular opacification in patients who have had extracapsular cataract extraction. Despite wide clinical use, little is known about its molecular changes to ocular tissues. The present study was elucidated to evaluate the molecular changes caused by Neodymium: YAG [Nd:YAG] laser to the corneal lipids. Eyes of 20 rabbits underwent laser capsulotomy and four power settings were used. The rabbits were sacrificed after 6 weeks, corneal lipids were extracted and purified then the following studies were carried out: Fourier transform infrared [FTIR] spectroscopy, UV-spectra and determination of total lipids, cholesterol and phospholipids. The results demonstrated fluctuation in lipid profile associated with conformational changes after Nd:YAG capsulatomy, these changes are due to laser power. In conclusion, the corneas overcome these changes by increasing their stability and increasing the degree of unsaturation of their lipid components

Retinal rhodopsin of rabbits after treatment with different doses of melatonin

Recently, melatonin is a broad-spectrum antioxidant for both animals and plants. It prevents oxidative damage at the level of cells, tissues, organs and organisms. In the present study, the effect of different doses of melatonin [10, 100, 500 and 1000 mu g] on the retinal rhodopsin was studied after different periods of 24 hr, one, three and five months. The rabbits were injected with melatonin daily early in the morning. After the studied periods, rhodopsin was extracted then the following measurements were carried out on it; purification of rhodopsin using a column of calcium triphosphate and celite; electrophoretic separation using SDS-polyacrylamide gel and dielectric measurements in the frequency range of 105 - 107 Hz. The obtained results indicated that there was no change in the molecular weight of rhodopsin at different doses and periods. The dipole moment was decreased at low doses and increased at high doses of melatonin. From the obtained results, it was concluded that melatonin at physiological doses could be useful for the eye