ABSTRACT
Objective To observe the autofluorescence (AF) manifestation in related lesions of periphery retinopathy. Methods Sixty eyes of 42 patients with periphery retinopathy underwent the examination of Optomap fundus photograph (200°) and fundus fluorescein angiography (FFA). The HRA Ⅱ melanin-related near-infrared fundus autofluorescence (NIA, excitation 795 nm) and lipofuscin-related fundus autofluorescence (FAF, excitation 488 nm) were measured for all the patients. The AF was recorded with nine images per second, and then a final AF image with 55° view and 822 × 768 pixel was generated by the HRA. AF images can be valuable or valueless if there was or was not visible blood vessels and related retinal tissues on the image. AF from lesion regions can be normal or abnormal fluorescence comparing to the normal vascular and retinal tissue AF. The abnormal fluorescence was divided into no AF, weak AF and strong AF relative to the background grayscale. The grading consistency of abnormal fluorescence based on FAF and NIA examination was comparatively analyzed. Results Valuable AF images were captured in 53/60 eyes (88. 33%)and valueless AF images were captured in 7/60 eyes (11.67%). Among 53 eyes with valuable AF image, NIA showed normal fluorescence in 28 eyes (52. 83%), abnormal fluorescence with sheet-like, dot-shaped or stripped in 25 eyes (47.17%); FAF showed normal fluorescence in two eyes (3.77 % ), abnormal fluorescence with sheet-like, scattered along vessels or pigments in 51 eyes (96.23 % ).Twenty-five eyes with abnormal fluorescence were observed both in two examinations, including same grades in 18 eye (72.00%) and different grades in seven eyes (28.00%). Conclusion The AF manifestation with different levels exists in related lesions of periphery retinopathy.
ABSTRACT
Objective To observe the characteristics of fundus autofluorescence (AF) distribution at the posterior pole in normal subjects. Methods Seventy-nine normal subjects (156 eyes) were studied.Confocal scanning laser ophthalmoscope (cSLO) HRA2 was used to obtain the AF average image at the posterior pole. The distance was calibrated by Digimizer image analysis system. With umbo as the center,the macula was divided into foveola, foves, parafovea and perifovea areas which with the radius 175, 750,1250 and 2750 μm respectively. Each area was further divided into inferior, superior, temporal and nasal quadrants by two radial lines angle of 90°, except for foveola. The AF intensity in four quadrants of different macular regions and optic disc were measured. The AF intensity in vertical and horizontal direction of umbo was also measured. Then the effects of age, eyes, and gender on AF intensity in four quadrants of different macular regions were analyzed. Results There were statistically significant differences in AF intensity among optic disc and four quadrants of macular regions (F=528. 648, P＜0.05). AF distribution was V-type in vertical direction and M-type in horizontal direction. There were statistically significant differences between age groups in foveola, inferior parafovea, temporal parafovea, inferior perifovea,superior perifovea and temporal perifovea (P＜ 0. 01). There were no statistically significant differences between the two eyes (P＞0. 05). Between genders group, there were statistically significant differences in foveola, superior foves, inferior fovea, nasal fovea and temporal perifovea (P ＜ 0.05); no statistically significant differences in the other quadrants (P＞0. 05). Conclusions The distribution of AF intensity is inhomogeneous in macular regions and four quadrants of each region in normal subjects. AF intensity increases with aging. AF distribution is symmetrical in both eyes. There is probably no correlation between gender and AF intensity distribution.
ABSTRACT
Objective To investigate the ingestion, metabolism and subcellular localization of indocyanine green (ICG) in human retinal epithelial (RPE) cells. Methods RPE cells were incubated with 0.25 mg/ml ICG under the condition of 37℃ in the camera. The ICG granule and ultrastructure of RPE cells were observed under the electron microscopy after 1-, 4-, and 24-hour incubation, and the ICG autofluorescence was detected by fluorescence microscopy after the incubation for 1, 2, 4, 8, 12, 24, and 48 hours, respectively. The absorbency (A value) of ICG solution was measured at 805 nm with ultraviolet/visible specrtrometer. The standard curve of concentration of ICG was drawn and the related equation of concentration of ICG and the A value was calculated. After being incubated for 1, 2, 4, 8, 12, 24, 48, and 72 hours, respectively, the A value of supernatant fluid was calculated according to the equation. After incubated with ICG for 24 hours, one sample was observed under electron microscope and fluorescence microscope per week to evaluate the metabolizable period of ICG. Results ICG granules were distributed evenly after entering the RPE cells. After incubated with 0.25 mg/ml ICG for 24 hours, no significant change of the ultrastructure of the RPE cells was found. ICG granules accumulated in the cells as the time goes by and reached the peak after 24 hours, and then they decreased because of the slowdown of the metabolism. Few ICG was still remained in the cells 1 week later. Conclusions RPE cells may take in ICG actively. ICG metabolizable period in RPE cells is long, which may be one of the mechanisms of the toxicity of ICG to the retina in the vitreous operation.
ABSTRACT
Objective To detect the induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production in immunostimulated retinal pigment epithelial (RPE) cells to seek for the supplying of the arginine, a substrate for NOS; as well as the effects of produced NO on the tight junction of RPE-J cells. Methods Rat′s RPE-J cells were treated with interferon-?(INF-?), tumor necrosis factor-?(TNF-?) and lipopolysaccharide (LPS), and Northern and Western blotting were applied to analyze the expression of the citrulline-NO cycle enzymes and related enzymes and the effect of dexamethasone and cyclic adenosine monophosphate (camp) on the expression of iNOS. Immunocytochemistry reaction and Western blotting were used to evaluate the effect of produced NO on the tight junctions of RPE-J cells. Results iNOS and argininosuccinate synthetase (AS) were highly induced at both mRNA and protection levels in immunostimulated RPE cells while arginiosuccinate lyase (AL) was not induced. NO was produced by cells after stimulation with TNF?, IFN? and LPS. The induction of iNOS mRNA and the production of NO by these immunostimulated cells was further enhanced by cAMP. NO was produced from citrulline as well as from arginine. And the produced NO impaired the tight junction of RPE-J cells, decreased the production of tight junction related protein ZO-1. Conclusion In activated RPE-J cells, citrulline-arginine recycling is important for NO production, and the produced NO weakened the function of tight junction of RPE-J cells.