VASCULAR COMPLICATIONS OF DIABETES - PART 8

Việc chẩn đoán của bệnh tăng sinh được thực hiện lâm sàng sau khi kiểm tra kỹ lưỡng của võng mạc với giãn đồng tử, tốt nhất là sử dụng đèn biomicroscopy khe không liên hệ 78 hoặc 90 ống kính quang học. Trình tự bình thường của kiểm tra sẽ được trước hết là kiểm tra cực sau nơi neovascularization là phổ biến, | 164 SECTION III DIABETIC RETINOPATHY AND ASSOCIATED OPHTHALMIC DISORDERS New vessels on the optic disc NVD . on the disc or within one disc diameter from the optic disc Fig. . New vessels on the iris Fig. . DIAGNOSIS AND NATURAL HISTORY The diagnosis of proliferative disease is made clinically after a thorough examination of the retina with mydriasis ideally using slit-lamp biomicroscopy with a non-contact 78 or 90 dioptre lens. The normal sequence of examination would be to firstly examine the posterior pole where neovascularization is common arising from the optic disc or the larger vessels in the posterior pole followed by a sequential examination of each quadrant of the retina extending out to the periphery. Fig. New vessels elsewhere NVE . Fig. New vessels on the optic disc NVD . CHAPTER 18 PROLIFERATIVE DIABETIC RETINOPATHY 165 New vessels are most frequently found within 45 degrees of the optic disc and NVD is present in approximately 70 of cases of proliferative disease often in combination with NVE. Disc new vessels usually appear as fine vessels across the optic disc cup. New vessels are distinguished from normal vessels by their growth pattern and by being in a more superficial plane. They usually appear to emanate from a localized area of a retinal vein and the size of these vessels can vary considerably. Retinal new vessels can sometimes be difficult to differentiate from intraretinal microvascular abnormalities IRMA . NVE are on the retinal surface and will therefore grow over retinal structures such as other blood vessels and they also leak fluorescein profusely Fig. . New vessels eventually acquire a varying degree of enveloping fibroglial Fig. Iris new vessels. Fig. Fluorescein angiogram revealing extensive fluorescein leakage from retinal new vessels. 166 SECTION III DIABETIC RETINOPATHY AND ASSOCIATED OPHTHALMIC DISORDERS tissue and in the early stages the vitreous remains adherent to both the fibrovascular .