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Changxian Yi

Publications and source records attributed to Changxian Yi.

8 recordsLinked to original sources
PubMed2005

Effects of melatonin in age-related macular degeneration.

Age-related macular degeneration (AMD) is the leading cause of severe visual loss in aged people. Melatonin has been shown to have the capacity to control eye pigmentation and thereby regulate the amount of light reaching the photoreceptors, to scavenge hydroxyradicals and to protect retinal pigment epithelium (RPE) cells from oxidative damage. Therefore, it is reasonable to think that the physiological decrease of melatonin in aged people may be an important factor in RPE dysfunction, which is a well known cause for initiation of AMD. Our purpose is to explore a new approach to prevent or treat AMD. We began case control study with a follow-up of 6 to 24 months. One hundred patients with AMD were diagnosed and 3 mg melatonin was given orally each night at bedtime for at least 3 months. Both dry and wet forms of AMD were included. Fifty-five patients were followed for more than 6 months. At 6 months of treatment, the visual acuity had been kept stable in general. Though the follow up time is not long, this result is already better than the otherwise estimated natural course.1,2 The change of the fundus picture was remarkable. Only 8 eyes showed more retinal bleeding and 6 eyes more retinal exudates. The majority had reduced pathologic macular changes. We conclude that the daily use of 3 mg melatonin seems to protect the retina and to delay macular degeneration. No significant side effects were observed.

Aged↗
PubMed2004

[Acute retinal necrosis: a report of 19 cases].

PURPOSE: To improve the diagnose and treatment capacity on acute retinal necrosis (ARN). METHODS: Retrospectively analyse the manifestation, examination, diagnose, treatment and prognosis of the 19 cases with ARN in our Ophthalmic Center from January, 1996 to November, 2003. RESULTS: Nineteen cases had inflammation in anterior segment, vitritis, necrotizing retinitis and retinal vasculitis, except one patient. After treatment, visual acuity had been improved in 11 eyes (45.8%). Final visual acuity were lower than 0.05 in 11 eyes. Signs were controlled in 21 eyes(87.5%). CONCLUSIONS: The diagnose of ARN should be mainly based on clinical manifestation. Early and sufficient treatment with antiviral agents, corticosteroid and prophylactic laser photocoagulation, sometimes vitrectomy are the key point to control the disease.

Acyclovir↗
PubMed2003

Preliminary clinical observation of arteriovenous sheathotomy for treatment of branch retinal vein occlusion.

PURPOSE: To document the anatomic and functional improvement of six patients with branch retinal vein occlusion (BRVO) following successful arteriovenous adventitial sheathotomy (AAS). METHODS: Retrospective study of 6 patients (6 eyes) with BRVO treated with AAS. All patients were not eligible for laser photocoagulation and had both macular edema and intraretinal hemorrhage. The visual acuity was in the range of 0.4 to 0.02. All patients underwent pars plana vitrectomy and AAS. The clinical improvement was determined by fundus photograph, fluorescein angiography (FAG), optical coherence tomography (OCT) and multifocal electroretinography (ERG). All patients were followed postoperatively for an average of 20 months ranging from 12 to 24 months. RESULTS: Sheathotomy and decompression of the arteriole/venule (A/V) crossing were achieved in all 6 patients. 5 patients have improved their best-corrected visual acuity 4 lines or more. The best one could reach to 1.0. One month after the operation, fundus photograph and FAG demonstrated the resolution of intraretinal hemorrhage, reduction of non-perfusion area and apparent resolution of retinal venous dilation and tortuosity. OCT confirmed remarkable reduction of retinal thickness. The microcysts at the fovea diminished. Multifocal ERG showed the recovery of the central peak at the macular and the peripheral response density. However, capillary nonperfusion area and microaneurysm were found out by FAG in four patients at the points distal to the sheathotomy three months after the operation. CONCLUSIONS: Anatomic and functional improvement of retina can be achieved in patients with BRVO through AAS. However, the capillary nonperfusion and microaneurysm may follow this surgical procedure in some cases that need further treatment with laser photocoagulation. The better visual improvement may be expected in the patients with earlier surgical intervention.

Aged↗
PubMed2003

Changes of indocyanine green and fluorescein angiography in multiple evanescent White-dot Syndrome: a case report.

PURPOSE: To study the clinicopathological change on "Multiple Evanescent White-dot Syndrome (MEWDS)" through fundus angiography analyses. METHODS: Examining the case with fluorescein angiography (FFA) and indocyanine green angiography (ICGA), visual field and following up for 15 months. RESULTS: There exist multiple white dots in the fundus photo and angiography. The changes on ICGA maintain longer than fundus photo and FFA. Papillae may be edematous and macula could present with special hypofluorescent flecks. CONCLUSIONS: MEWDS has specific angiographic features. Its pathological changes involve deep retinal pigment epithelium (RPE) as well as choroidal capillaries. The prognosis of the visual acuity for MEWDS is very good.

Adult↗
PubMed2002

[Affection on oxygen tension of the lens after vitrectomy].

PURPOSE: To measure the oxygen tension (PO2) in the rabbit vitreous and lens and to investigate the mechanism by which it is controlled, the affection on oxygen tension of the lens after vitrectomy was studied. METHODS: Using a fiber-optic oxygen sensor system, oxygen tension of the rabbit vitreous and lens was probed in vivo and oxygen permeability of posterior capsule was also measured on isolated rabbit lens. RESULTS: It was found that with agreement with previous study, PO2 is relatively high and the PO2 gradient is large in vitreous body close to the retina whereas more than 0.5 mm away from the retina the vitreal PO2 is relatively low and the PO2 gradient is very shallow. Oxygen tension in the lens is asymmetric with the anterior being higher than the posterior and oxygen in the posterior lens being at the similar tension as the anterior vitreous behind the lens. The posterior capsule of the rabbit lens is relatively high in oxygen permeability. CONCLUSIONS: The vitreous body plays a key role in maintaining a low and stable level of oxygen in the lens. After vitrectomy oxygen tension in the lens may increase.

Animals↗
PubMed2002

[Angiographic changes in optic disc and its surrounding choroid after contusion of optic nerve].

PURPOSE: To study the angiographic changes in the optic disc and its surrounding choroidoretina after optic nerve contusion with fundus fluorescein angiography (FFA), and indocyanine green angiography (ICGA). METHODS: Thirty patients (30 eyes) with various degree of optic nerve damage caused by ocular contusion were examined with FFA and ICGA. (The choroidal rupture were excluded in this study). RESULTS: All patients present some abnormal angiography except one case. The main findings in FFA were hypofluorescein on quadrantal or entire disc in the early phase and leakage or persistent nonperfusion in the late phase. Meanwhile, the choroid surrounding disc was clearly delayed in its choroidal filling time. The retinal pigment epithelium (RPE) damage was observed over the localized abnormally perfused choroid. However, the RPE above the circular area around the disc which was hypofluorescein in ICGA showed no RPE damage in 9 cases. There are 2 cases combined with branche retinal vein occlusion and 19 (63%) cases showed ischemic changes exactly on the location of so-called "water separating zone". The visual acuity was not more than 0.1 in 80% of the patients in this study. CONCLUSIONS: There is severe optic nerve lesion in the strong ocular contusion, in which the choroidal and retinal arterial circulation has also been seriously damaged. The FFA and ICGA should be conducted in time in order to judge the injury correctly and allow the clinician to better manage the cases.

Adolescent↗
PubMed2002

[Retinal vasculitis].

Retinal vasculitis is one of the frequently cause of impair of visual acuity. The vein is involved most of time, and the artery is involved less. Sometimes, the vein and artery are involved together. The types and cause of the disease are complex. In recent years, ophthalmologists have gotten some new achievements on the study of the disease, and some arguments just like naming, diagnosing and treatment still exist. Now we review all the achievement and arguments of the naming, clinic, pathology, etiology, experiment, diagnosing, treatment of the disease.

Humans↗