In the absence of clinically apparent foveal toxicity, CFT, SFCT together with ring amplitude ratio could be used as good predictors of subclinical nicotine induced foveal changes.
Aim. To evaluate the possible structural and functional changes in the retinal nerve fibre layer (RNFL) and the ganglion cell complex (GCC) of chronic smokers and compare them with those of passive healthy smokers using spectral domain optical coherence tomography (SD-OCT) and pattern electroretinogram (PERG). Materials and Methods. We include 80 active chronic smokers and 80 age- and sex-matched healthy passive smokers. After a full ophthalmological examination, SD-OCT and PERG were tested for all participants. Urinary levels of cotinine and creatinine with subsequent calculation of the cotinine creatinine ratio (CCR). Results. Inferior and superior quadrants of RNFL were thinner in group I, but nasal and temporal quadrants did not show significant difference between the groups. There were no significant differences of GCC values between the two groups. There was no significant difference of PERG-P50 amplitude and latency; however, PERG-N95 showed significant difference between the two groups. Multiple regression analyses demonstrated that the number of cigarettes/day, urinary cotinine, and PERG-N95 amplitude are the most important determinants for both superior and inferior RNFL thicknesses. Conclusion. RNFL thickness decreases in chronic, healthy, heavy cigarette smokers, and this thinning is related to the number of cigarettes/day, urinary cotinine, and PERG-N95 latency and amplitude.
Purpose. To identify and correlate age-related changes in outer retinal layers’ thickness and choroidal thickness (CT) in the normal eyes using spectral-domain optical coherence tomography (SD-OCT) and to investigate factors affecting these changes. Study Design. Observational cross-sectional study. Subjects and Methods. We studied 125 healthy Egyptians between 20 and 79 years old. Patients were divided into 3 groups: group 1 (20–40 years), group 2 (40–60 years), and group 3 (>60 years). All patients had full ophthalmic examination. SD-OCT was done to measure the 9 ETDRS macular grid sectors of retinal pigment epithelium and photoreceptor outer segment (RPE-OS), outer nuclear layer and photoreceptor inner segment (ONL-IS), and choroidal thickness (CT) (by enhanced depth imaging). Results. RPE-OS was significantly thinner in group 3 than in the other 2 groups (central: P<0.001). Moreover, the 3 groups were significantly different from each other regarding the CT (central: P<0.001); significant thinning was noticed in the choroid with age. The 3 groups did not show significant difference concerning the ONL-IS thickness. RPE-OS and CT showed statistically significant negative correlation with age (central RPE-OS: r = −0 C.345, P<0.001, and central CT: r = −0.725, P<0.001) while ONL-IS showed statistically nonsignificant correlation with age (central ONL-IS: r = −0.08, P=0.376). Multiple regression analysis revealed that the most important determinant of central 1 mm RPE-OS thickness in this study was age (β = −0.087, P=0.010) rather than choroidal thinning (β = 0.001, P=0.879). Conclusion. RPE-OS layer thickness shows significant thinning with increasing age, and with decrease in CT, however, age is the most determinant factor of this thinning.
Aim: The aim of this work was to study histological and immunohistochemical changes resulting from corneal alkali burn and to assess these changes after treatment with either polysaccharide extract from Spirulina platensis (PSP) or Bevacizumab.
Methods:Alkali burn was induced in corneas by direct application of a filter paper ring (2.5 mm diameter) saturated with 1 N NaOH and applied to the center of the rat corneas for 30 seconds. PSP (extracted from dry powder of Spirulina platensis) and avastin were administered topically on the corneas 4 times daily for 7 days starting 7 days after induction of corneal alkali burn. The therapeutic effects of PSP and avastin were evaluated daily using slit-lamp. At the end of the therapy, corneas were harvested for H and E staining, Masson trichrome staining, immunohistochemical study for assessment of inflammation and corneal neovascularization (CorNV).Results: Topical application of either PSP extract or Avastin had significant therapeutic effects on corneal injuries induced by alkali burn. This was demonstrated by decreasing the CorNV, total and differential corneal thickness and inflammatory cellular responses. They increased the epithelial thickness. PSP showed better results than Avastin in this regards.
Conclusion:The naturally occurring Spirulina platensis (PSP) is more cost effective in treatment of corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn as compared to Avastin.
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