ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Retinopathy of prematurity (ROP) continues to be an important cause of potentially preventable blindness worldwide. The pattern of visual impairment from ROP in some middle-income countries—high rates affecting larger and more mature infants—resembles that seen in more developed countries two decades ago and has been called a “third epidemic” of the disease. Expert bodies in the United Kingdom and the United States have recently issued new guidelines for screening for ROP that utilize both birth weight and gestational age criteria. Studies in both countries suggest these criteria might be further revised to decrease time spent on screening without missing any significant disease. Population-based follow-up studies of extremely preterm infants suggest that although more preterm infants are surviving, with adequate screening and treatment, rates of blindness from ROP may be declining. Further information on the longer-term impact of ROP comes from a number of studies and particularly the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study. The risk of both myopia and strabismus is increased with any and each higher stage of ROP. Evidence is emerging that laser therapy for threshold disease may be associated with better visual outcome than cryotherapy, although complications following the former remain a concern. The fight against ROP may be enhanced by new information on the pathogenesis, including possible genetic predisposition and the role of vascular endothelial growth factor.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Choroidal metastases and melanomas are the most common intraocular neoplasms. Choroidal metastases may appear clinically similar to other amelanotic tumors, and the diagnosis may be difficult in the absence of a history of extraocular malignancy.Ultrasonography, using A- and B-mode criteria, offers an opportunity for high accuracy in the diagnosis of choroidal tumors. However, a considerable overlapping of ultrasonographic parameters, such as tumor solidity, vascularity, and choroidal excavation, has been demonstrated for choroidal melanomas and metastases.We have found that choroidal metastases are characterized by a significantly lower height-to-base ratio than melanomas, whereas reflectivity is significantly higher in metastases. Thus the combined use of height-to-base ratio and reflectivity provides a highly significant differentiation between choroidal melanomas and metastases. This observation has further improved the diagnostic value of ultrasonography in the differentiation of choroidal tumors.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) is the most frequent extraintestinal manifestation of familial adenomatous polyposis. Present in 70% of families with familial adenomatous polyposis, CHRPE is a highly reliable and early marker of the disease. Studies over the past 5 years have addressed the histologic characteristics of the pigmented fundus lesions, the definition of universal positive fundus criteria, and mostly the genotype–phenotype correlation. Indeed, the position of the mutation site of theAPC(adenomatous polyposis coli) gene on chromosome 5 influences the retinal expressivity because CHRPE is present only if the mutation is located between exons 9 and 15. In CHRPE-positive families, fundus examination is simple, noninvasive, reproducible, inexpensive, and allows early detection of the mutant gene carriers. Knowing the CHRPE status of patients in a family with familial adenomatous polyposis helps to identify constitutionalAPCmutations. The combination of genetic analysis and fundus examination offers a 100% diagnostic predictability.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Recent reports of retinal pathology associated with laser refractive surgery are documented. The overall risk of retinal disease following photorefractive keratectomy or laser-assisted in situ keratomileusis is discussed, and the potential causal associations between anterior segment laser and posterior segment pathology are assessed.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Choroidal neovascularization (CNV) is the most common cause of legal blindness in older adults in the United States. The most common cause for CNV in this age group is age-related macular degeneration, a condition manifesting with drusen (particularly soft drusen) and pigmentary alterations in the macular region. CNV can occur in younger people (< 50 years), who usually do not have conspicuous drusen or pigmentary abnormalities. In this age group CNV may occur as a secondary manifestation of many inherited and acquired conditions such as angioid streaks, high myopia, trauma, choroidal tumors, familial macular dystrophies, and inflammatory retinochoroidopathies. Occasionally, CNV in young people has no apparent antecedent cause, and these cases are termed “idiopathic CNV.” This review examines the common reasons for CNV in young adults, with reference to some of the older literature as well as to recently published papers.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Optical coherence tomography is a new diagnostic tool for high-resolution imaging of ocular tissues. Ocular coherence tomography produces cross-sectional images of the retina with a longitudinal resolution of 10 &mgr;m. This provides the most highly resolved retinal imagesin vivowhen compared with other available techniques. It has been used to study the anatomy and pathogenesis of various ocular disorders affecting the posterior segment. These include vitreomacular traction syndrome, macular hole, retinoschisis, macular edema, central serous chorioretinopathy, subretinal neovascularization, age-related maculopathy, optic nerve disorders, and nerve fiber layer evaluation in glaucoma.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Recent developments in the clinical application of indocyanine green angiography have mainly concerned refining its role as an adjunct to fluorescein angiography in detecting and guiding the treatment of choroidal neovascularization. We now have a better understanding of the different patterns of abnormal hyperfluorescence seen with indocyanine green angiography in eyes with both wet and dry forms of macular degeneration. In exudative cases, the success rate of laser treatment guided by indocyanine green angiographic findings can vary considerably, and it is now known which angiographic presentations are not as likely to benefit. In dry macular degeneration, indocyanine green angiography appears to add clinically useful information, such as helping to identify plaques in fellow eyes with choroidal neovascularization or watershed zones that may be predictive of future exudative transformation. In certain circumstances, indocyanine green angiography can be valuable in detecting choroidal neovascularization in other macular diseases or in helping to diagnose other choroidal conditions, especially when the clinical presentation is atypical, such as central serous chorioretinopathy in elderly patients.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The management of choroidal melanomas depends on many factors, most importantly, tumor size and location. Small choroidal melanoma in the posterior fundus is amenable to treatment options such as enucleation, radiotherapy, laser photocoagulation, and transpupillary thermotherapy or a combination of these methods. Transpupillary thermotherapy is a technique of tumor heating by infrared radiation delivered through the pupil into the tumor. This method causes dramatic tumor necrosis in choroidal melanomas up to 4 mm in thickness. With properly selected small choroidal melanomas, tumor control is approximately 94%. The heat induces cellular damage at the site of treatment with few remote side effects; therefore, complications are generally limited to the site of treatment and include retinal vascular obstruction (23%), retinal traction (20%), retinal neovascularization (6%), and retinal hole with detachment (< 1%). Tumors located temporal to the foveola demonstrate a statistically higher risk for retinal traction than those located in other quadrants. Tumors near the optic disk demonstrate a higher incidence of retinal neovascularization due to heat-induced obstruction of a major retinal vascular arcade. Overall, vision preservation is satisfactory after thermotherapy for choroidal melanoma, with more than 50% of patients maintaining the same or better vision after treatment, depending primarily on tumor location. In summary, small choroidal melanomas can be controlled with transpupillary thermotherapy, especially those near the optic disk and foveola in areas that are otherwise difficult to irradiate. Longer follow-up is necessary to assess for local recurrence and the impact of treatment on life prognosis.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

During the past several decades, many individuals have noted that drusen may resolve after macular laser photocoagulation. The lack of effective therapies against choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) has prompted many investigators to explore strategies designed to prevent CNV in eyes with high-risk drusen. Currently, several pilot studies in the United States, Spain, Sweden, Australia, and the United Kingdom are in progress; the Choroidal Neovascularization Prevention Trial (CNVPT) is the largest pilot study to date and is detailed herein. A definitive study, the Complications of Age-Related Macular Degeneration Prevention Trial, aims to evaluate the effects of laser treatment in patients with bilateral drusen and will commence this year.

ISSN:1040-8738    

出版商:OVID    

年代:1999

数据来源: OVID