| IntroductionDiabetes mellitus is a group of common metabolic endocritic disease, its basic pathophysiological changes are absolute or relative insulin deficiency and hypcrglucagonemia .which lead to metabolic disturbance in many organs. Uncontrolled diabetic retinopathy (DR) is one of the main causes of persistent blindness in human. Presently the clinical therapy is photocoagulation in early stage of DR to control the process and attain the better prognosis. It is important to find the lesion earlier. With the development of research in DR, Some physicians now believe diabetes will affect choroidal vessels, which lead to retinal pathological changes . Indocyanine green angiography (ICGA) is a useful method to observe choriodal vascular circulation directly and dynamically . 1 he present study was conducted to evaluate ICGA in early stage of DR.PurposeTo report angiographic findings of early stage (nonproliferative phase) of diabetic retinopathy by means of indocyanine green angiography.Subjects and Methods26 eyes of 22 consecutive patients (male 8 cases, female 14 cases , aged 46-71 years ) were selected randomly in Hangzhou No.1. hospital. Include criteria: (1) II type diabetes (2) Courses 1-12 years (3) I -III phase DR, confirmed by ophthalmoscope and fundus fluorescein angiography (FFA). Hxclude criteria: (1) Hypersensitivities and allergies , thyroid diseases , severe hepatic and renal diseases , pregnancy ; (2) llyperl es ion. Hyper] ipidemia .glaucoma , retinal and/or choroidal vascular occlusion, age-related macular degeneration, pathologic myopia; (3) severe refractive media opaqueness (4) photocoagulation and intraocular operations already . Twenty-six eyes (17 right eyes and 9 left eyes) were evaluated by ICGA and FFA.Twenty-four age and gender matched "healthy" controls were studied to compare the choroidal dynamics . ICGA and FFA were performed with the use of the Topcon SOX fundus camera, all images were analyzedwith matched OIS Winstation Imaging System.ResultsCompared with controls, the times of fluorescent appearance of earliest and strongest, phase were delayed in early stage of DR respectively , which had statistical significance (t-test and t' -test), pointed out the choroidal circulation deficiency. Compared with FFA findings, ICGA in early stage of DR had five main features:(1)the times of fluorescent appearance of earliest and strongest phase were delayed respectively, there were hypofluorescene area appeared in midphase with local leakage hyperfluorescence (2) Choroidal veins were dilated and hyperf luorescene before vortex veins in 20 eyes(76.5%) of II "III phase DR. (3) Microaneurysms were divided into three types: a. 20 eyes(100%) had microaneurysms seen very faintly on ICGA hut hyperf1uoresced and leaked on fluorescein angiography , b. 15 eyes(56. 9%) had microaneurysms that were noted on both ICGA and FFA.c. 6 eyes(23.1%) had microaneurysms that were prominently seen on ICGA but did not appear on FFA. (4) 3 eyes (11. 5%) had the patchy, spotted hyperfluorcsceint./hypofluoresceint pattern that was described as"salt and pepper" appearance in later phase over the posterior pole area. (5)2 eyes(7. 7%) had midphase appeared and increased with time hyperfluorescence in area with macular edema, which only showed microaneurysms in FFA.During angiography, there was no allergic reaction in ICGA, 2 cases had allergic reaction in FFA, they were recovered shortly after rest.ConclusionIndocyanine green angiography in patients with early stage of diabetic retinopathy discloses choroidal circulation characteristics and microvascular findings, which are in addition to those shown on fluorescein angiography. Outer 5 layers of retina are supplied by choroidal circulations, so lesions in choroid play an important role in DR. But which one is involved firstly or both, we need further investigation , long-term evaluation and necessary pathological examinations. |
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