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Secondary Open-Angle Glaucomas
Published in Neil T. Choplin, Carlo E. Traverso, Atlas of Glaucoma, 2014
Jonathan Myers, L. Jay Katz, Anand Mantravadi
Ocular trauma remains a common cause for emergency room visits and hospital admissions, being most frequent among young males. Causes vary with age: play-related accidents in young children, sports and assaults in young adults, and work and domestic accidents or abuse in older adults. The mechanism of trauma often dictates the specific injuries to the eye; almost all may lead to glaucoma. Nonpenetrating injuries of the eye secondary to blunt trauma are usually related to the anterior-to-posterior compression of the eye with secondary equatorial stretching. This stretching may result in pupil sphincter tears, iridodialysis, angle recession, cyclodialysis, trabecular dialysis, disruption of the zonules, and retinal dialysis or detachment. Tears in the face of the ciliary body, usually between the circular and longitudinal muscles, may disrupt the major arterial circle of the iris and the arterial and venous connections of the ciliary body resulting in hyphema. Severity may range from a microhyphema, in which the slit-lamp microscope is necessary to appreciate the presence of blood in the anterior chamber, to total hyphema, in which the anterior and posterior chambers are entirely filled with blood (Figures 10.18 and 10.19). Following injury, IOP may be elevated or reduced, depending on the balance of several factors. Aqueous secretion may be acutely reduced; uveoscleral outflow may be increased by an accompanying cyclodialysis; blood may obstruct an injured and inflamed trabecular meshwork. Although red blood cells normally pass through the pores in the meshwork, acute inflammation and swelling of the meshwork combined with excessive amounts of red blood cells and debris may overwhelm the meshwork’s capacity.
Iris vessel dilation and hyphema due to forceps trauma in a newborn
Published in Journal of Obstetrics and Gynaecology, 2019
Alexandra Tantou, Maria Kotoula, Petros Koltsidopoulos, Evangelia Tsironi, Eleni Papageorgiou
The iris and ciliary body are supplied by the anterior ciliary arteries, the long posterior ciliary arteries and anastomotic connections from the anterior choroid vasculature (Kiel 2010). The two long posterior ciliary arteries arise from the ophthalmic artery, pierce the sclera near the posterior pole, and then travel forward to the ciliary body, where they anastomose to form the major arterial circle of the iris. The anterior ciliary arteries travel with the extraocular muscles and pierce the sclera near the limbus to also join the major arterial circle of the iris (Kiel 2010). The iris and ciliary body are drained primarily through the anterior ciliary veins, which participate in the vortex vein system, finally emptying into the cavernous sinus and the jugular veins. The underlying mechanism for an iris haemorrhage may be due to the compression of the foetal head in the birth canal, which is exacerbated by forceps use (Choi et al. 2011). Specifically, under those circumstances the intracranial and central venous pressures increase, which is accompanied by the venous stasis and the engorgement of the ophthalmic veins due to the venous return obstruction (Choi et al. 2011). The iris veins have very thin walls consisting of endothelium surrounded by a thin layer of collagen, thus being susceptible to rupture and haemorrhage. Additionally, a possible hypoxia during a forceps-assisted delivery might be a cause of an iris haemorrhage. It has been suggested that an autoregulatory hypoxic cerebral vasodilatation produces an increase in the intracranial pressure, which in turn increases the retinal venous pressure (Geddes et al. 2003).
Snowflakes in the Eye – An Uncommon Presentation of Iris Metastasis of Esophageal Carcinoma and Review of Literature
Published in Ocular Immunology and Inflammation, 2022
Wei Liu, Wenjiang Ma, Ruru Guo, Jian Ji
In the largest published series of 107 eyes with metastatic tumors of the iris, Shields et al.5 found over a 40-year period, only three cases had the esophagus as a primary origin of cancer. To the best of our knowledge, there are only eight reported cases of iris metastasis from esophageal carcinoma (Table 1).6–11 Iris metastases may present as stromal nodules or ill-defined iris thickening.12 Shields et al. reported the manifestations of an iris metastatic tumor can be flat (27%), nodular (67%), or papillary (6%).5 For iris metastasis from esophagus cancer (Table 1), two patients presented with nodular mass, three patients with vascularized lesion and four patients with iris thickening or iris infiltration. The underlying mechanism of different iris appearance remains unclear. We speculate the various iris manifestations may be resulted from the different primary tumor subtype, different tumor stage and different presenting times of the patients. Shields et al.5 found that most of iris metastases were inferior (35%) and superior (28%), while in another case series,13 the majority of cases were nasal (28%) and temporal (28%). Iris metastases often appear near the iris root or the irido-corneal angle,5 which seems to confirm the theory that they are related to the major arterial circle of the iris and spread via the blood system.14 Shields et al.5 in their study of 160 metastatic tumors to the iris demonstrated iris metastasis most often are unilateral (97%), but bilateral metastases do occur (3%). However, in our literature review (Table 1), all the iris metastases from esophageal carcinoma were unilateral.