| Research backgroundMacular is a very important region in fundus related to vision,color sense function directly.When macular suffered from illnesses,central vision acuity will decline sharply and the main clinical symptoms are :floaters,vision blurred and metamorphosis. How to diagnosis accurately is an important prerequisite for treatment of macular diseases.The more common macular diseases or/and symptoms include: central serous retinopathy, macular edema, macular hole, macular epiretinal membrane etc..Optical coherence tomography(OCT) is a new optical diagnostic technique for macular diseases.Because of optical characteristics,when the patients with ocular media opacity such as corneal opacity, cataract and vitreous hemorrhage,OCT is unable to diagnose clearly.Then we need ultrasound examination for diagnosis in those situations. The ultrasound frequency commonly used in ophthalmology is 10 MHz which is widely used but with low resolution.So it has a poor effect in details of fundus disease. Although some researches of 20MHz frequency ultrasonography for diagnosis of fundus disease reported, there are lack of systematic research reports. Through the observation of a series patients with macular disease who were diagnosed by 20MHz ultrasound and analysed image systemly, we tried to find the effect in the diagnosis of macular diseases in effect of 20MHz frequency ultrasonography.ObjectiveTo observe the value of 20MHz high frequency ultrasound in the diagnosis of macular diseases included:macular edema, macular hole, macular retinoschisis etc..Then we analyzed the image characteristics of those macular diseases.Methods:We selected 363 patients(726 eyes)in our hospital from January 2015 to September 2015 both in hospital and out-patient. Optical coherence tomography(OCT) was used as the gold standard for the diagnosis. 216 patients(327eyes) with macular disease were selected as positive group and 399 eyes as the negative control group.All patients were checked by the slit lamp, preset endoscopy, Optical coherence tomography,fundus fluorescence angiography(FFA),Indocyanine green angiography(ICGA).Positive group contained:169 eyes with macular edema which were comprised by 57 eyes of diabetic macular edema, 45 eyes of vein occlusion(CRVO and BRVO), 53 eyes of central serous chorioretinopathy(CSC) and 14 eyes of other reasons;40 eyes of macular epiretinal membrane;48 eyes of age-related macular degeneration;44 eyes of macular hole without retinal detachment;15 eyes of macular retinoschisis;11 eyes of retinal detachment caused by macular hole.The patients in positive group included 109 males and 97 females.Mean age was 53.2±11.4 years old. All patients were examined by the same doctor and divided to two groups wihch we mentioned above.Then another doctor who did not know the diagnosis did the examination with 20MHz ultrasound.We observed indexes like the sensitivity and specificity of ultrasound. Then we observed the coincidence rate of ultrasound in diagnosis of different diseases.Ultrasounic image characteristics were analysed and compared with OCT images.Results:1.The patients could be dignosed as macular disease by both ultrasonography and optical coherence tomography were 277 eyes,be diagnosed with no macular diseaseby both ultrasonography and optical coherence tomography were 365 eyes.There were 34 cases dignosed by ultrasonography with macular diseases but without by OCT; There were 50 cases dignosed by ultrasonography without macular diseases but with macular diseases by OCT. We calculated that the sensitivity of 20MHz ultrasound was 84.7%, the specificity was 91.5%,false negative rate of 15.3% and the false positive rate was 8.5%. Youden's index was 0.762. In addition,the positive likelihood ratio of B-scan ultrasonography was 9.96 and the negative likelihood ratio was 0.167. To sum up, 20MHz B-scan ultrasound in diagnosis of macular diseases is useful and valuable.2.The ultrasonic image of macular hole showed that macular retina was thicken and a strong echo of shallow dome-shaped lesion with a central hollow was exhibited. The cord-like echo discontinued and low level echo could observe below it. The dome-shaped lesion with a central hollow we obersed liked a "saddle" and diameter of hollow was wider, the discontinuation of echo was more obvious. The minimum diameter of the hollow we could find out is about 0.2mm.The ultrasonic image of macular edema showed that in the surface of macular region a local peak like echo or superficial and irregular banded medium echo protruded coule be seen. The center of echo might be discontinuous below which anechoic area might be obeserved. The thicker macular was the protruded surface was more obvious.The ultrasonic image of retinal detachment with macular hole showed that local, irregular and flat arch-shaped uplifted echoes which was moderate to strong echoes, below which there was anechoic gap.We observed uplifted echo fractured if hole was bigger. The ultrasonic image of Macular retinoschisis showed \peak-shaped or arc-cord like uplifted medium echoes could be seen below which there was anechoic gap.The ultrasonic images of retinal detachment with macular hole and macular retinoschisis were analogous.The ultrasonic image of macular epiretinal membrane showed local and superficial banded and uplifted hyperechoes with a thicker bank, below which there might be anechoic gap. In some cases scattered low level echoes might be seen in the anechoic gap.The ultrasonic image of age-related macular degeneration show echoes like slender cord and flat regularly or echoes like peak-like uplifted with no-echo zone below. The farther away was from the fovea the uplifted echoes were more flater..Conclusions:1. 20MHz B-scan ultrasound has a certain value in diagnosis of macular diseases with have high sensitivity and specificity; but has low detective rate in the patients with macular epiretinal membrane and age related macular degeneration;2.Most macular diseases have their own 20MHz B-scan ultrasonic characteristic images;3. 20MHz B-scan Ultrasonic findings of retinal detachment caused by macular hole and macular retinoschisis are similar, sometimes difficult to distinguish;4.In the opacity of refractive media or nystagmus, 20MHz B-scan ultrasound is effective examination means in diagnosis of macular diseases. |
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