Hypopyon and iris necrosis in angle-closure glaucoma. Report of two cases

Uveal vascular bed in health and disease: lesions produced by occlusion of the uveal vascular bed and acute uveal ischaemic lesions seen clinically. Paper 2 of 2

From studies on postmortem anatomical descriptions of the uveal vascular bed, it was generally concluded that occlusion of PCA or its branches should not produce an ischemic lesion. However, in vivo studies have recorded that the PCAs and their branches, right down to the terminal choroidal arterioles, and the choriocapillaris, have a segmental distribution in the choroid, and that PCAs and choroidal arteries function as end-arteries. This explains the basis of the occurrence of isolated inflammatory, ischemic, metastatic, and degenerative choroidal lesions, which are usually localized. Thus, in vivo studies have completely revolutionized our concept of the uveal vascular bed in disease.

Postprocedural Endophthalmitis or Postprocedural Intraocular Inflammation: A Diagnostic Conundrum

We experienced an atypical endophthalmitis occurring post consecutively performed in-office procedures; an intravitreal injection (IVI) of ranibizumab followed by an anterior chamber (AC) paracentesis performed twice in an eye with neovascular glaucoma (NVG). A 52-year-old diabetic male who was asymptomatic developed signs of endophthalmitis and decreased vision without pain in his left eye a few days post-IVI and AC paracentesis. The condition worsened after an initial vitreous tap and injection of antibiotics. Cultures of vitreous and aqueous samples were negative. Complete resolution occurred after a pars plana vitrectomy with IVI of antibiotics and steroid with removal of a dense “yellowish-brown” fibrinous plaque. The absence of pain, presence of a peculiar colored fibrin, mild-to-moderate vitritis without retinitis, negative cultures, and complete recovery despite the fulminant presentation; favor a diagnosis of inflammation over infection. We hypothesize that a micro-leak from a 26-gauge AC tap tract might have served as an entry port for 5% povidone-iodine from the ocular surface thus inciting inflammation. However, an exuberant inflammatory response that can be typically seen in NVG eyes after intraocular procedures cannot be excluded. Various causes of inflammation post-procedures, both toxic and nontoxic should be considered in atypical culture-negative fulminant endophthalmitis cases with good outcome posttreatment. Any minor ocular procedure may carry a risk of such complication. Patient counseling and care must be exercised in performing these procedures.

Hypopyon uveitis

Hypopyon uveitis has inflammatory, infective, and neoplastic causes and a high association with systemic disease. Careful questioning of the patient and detailed examination of the eye for other signs is necessary to guide the differential diagnosis and relevant investigations. Because the underlying causes require very different types of investigation and, if missed, can have serious sequelae for the patient, a rational approach based on the understanding of the causes of hypopyon uveitis is imperative. In this review, hypopyon uveitis is considered in the context of the associated ocular and systemic diseases that cause it.

Glaucoma associated with uveitis

Raised intraocular pressure is a common and frequently serious complication of anterior uveitis. The milieu of inflammatory cells, the mediators they release, and the corticosteroid therapy used to treat the uveitis can participate in the pathogenesis of uveitic glaucoma. These factors alter the normal anatomic structure of the anterior chamber and angle, influencing aqueous production and outflow. These changes act to disrupt the homeostatic mechanisms of intraocular pressure control. Structural changes in the angle can be acute, such as in secondary angle closure with pupillary block glaucoma, or chronic, such as combined steroid-induced and secondary open angle glaucoma. Management of uveitic glaucoma may be difficult because of the numerous mechanisms involved in its pathogenesis. Diagnostic and therapeutic decisions are guided by careful delineation of the pathophysiology of each individual case. The goal of treatment is to minimize permanent structural alteration of aqueous outflow and to prevent damage to the optic nerve head. This article reviews the pathogenesis of uveitic glaucoma, with specific attention to etiology. Medical and surgical therapies are also discussed, with emphasis on the more recent developments in each category.

Hypopyon--an unusual sign in acute angle-closure glaucoma

The appearance of a hypopyon is an extremely uncommon finding in acute angle-closure glaucoma and only a few cases have been previously reported in the literature. We report a fifty-year-old female who, following a recent bereavement, presented with classical features of acute angle-closure glaucoma and a hypopyon. The eye developed a glaukomflecken and the patient underwent trabeculectomy, extracapsular cataract extraction and intraocular lens implantation with good post-operative results. Because hypopyon in acute angle-closure glaucoma is rare and may cause diagnostic confusion and hence therapeutic difficulties, this case is described to highlight this unusual clinical sign.