Peripheral Anterior Chamber Research Articles

Transient Shallow Anterior Chamber Induced by Supraciliary Fluid After Vitreous Surgery

To report the mechanism of transient shallow anterior chamber after vitreous surgery for proliferative diabetic retinopathy. Using ultrasound biomicroscopy, we examined a patient with transient shallow anterior chamber after vitreous surgery for proliferative diabetic retinopathy. On the day after surgery, slit-lamp examination disclosed a shallow anterior chamber that persisted for 1 week and deepened thereafter. Ultrasound biomicroscopy 5 days postoperatively disclosed a narrow angle in the peripheral anterior chamber and supraciliary fluid. At 14 days postoperatively, suprachoroidal fluid could not be detected, and the angle was wide. The shallow anterior chamber in this patient was caused by supraciliary fluid after vitreous surgery.

Cyclocongestive angle closure glaucoma: a diagnostic challenge

The cyclocongestive angle closure glaucomas are a group of disorders in which choroidal congestion produces forward rotation of the ciliary body, resulting in closure of the peripheral anterior chamber angle. Continued aqueous production induces an acute rise in intraocular pressure. The following case report illustrates and discusses the presentation, etiologies, pathogenesis, differential diagnosis and management of this rare clinical entity. Since prompt intervention in cyclocongestive angle closure glaucoma is crucial, optometrists should be familiar with this set of disorders as well as optimal comanagement strategies.

Vitrectomy for Ciliary Block (malignant) Glaucoma

Ciliary block (malignant) glaucoma is a rare surgical complication occurring in patients with pre-existing glaucoma. Misdirected aqueous fluid causes forward movement of the lens/iris diaphragm, shallowing the central and peripheral anterior chamber. Although most patients with ciliary block respond to medical or laser therapy, those with refractory glaucoma often require pars plana vitrectomy to normalize aqueous flow. The medical records of 21 consecutive patients with refractory ciliary block glaucoma treated by pars plana vitrectomy were reviewed retrospectively to determine the efficacy of this procedure in alleviating ciliary block. Data were collected regarding anatomic characteristics of the eye, history of glaucoma, prior ocular surgery, and outcome after vitrectomy. Pre-existing glaucoma and recent intraocular surgery were noted in all patients with ciliary block glaucoma. Of 21 eyes, 8 (38%) had undergone multiple prior intraocular surgeries. The initial pars plana vitrectomy was successful in alleviating ciliary block in 14 (70%) of 20 eyes. Of those six eyes that failed to improve after initial vitrectomy, five (83%) were phakic. Additional vitrectomy surgery to relieve ciliary block was required in three (60%) of five phakic patients who failed initial vitrectomy. Complications during the treatment of ciliary block included cataract formation, retinal detachment, bleb failure, and serous choroidal detachment. Pars plana vitrectomy is a useful adjunct to therapy for ciliary block glaucoma when medical and laser treatment fail to alleviate the process. Surgically removing the anterior hyaloid to re-establish normal aqueous flow constitutes the primary goal of surgery. In some cases, surgery is compromised by poor visualization of the anterior hyaloid, avoiding glaucoma filtration sites, and guarding against damage to the crystalline lens.

Zur Biometrie der Augenvorderkammer bei der Nd:YAG-Laseriridektomie

In a prospective clinical study covering 41 eyes (28 patients) with narrow-angle glaucoma the central and peripheral anterior chamber depths were determined biomicroscopically before and after Nd:YAG laser iridectomy. In 29 eyes the central anterior chamber depth was also measured by ultrasonography. In contrast to the increase in central anterior chamber depth, which was only slight, the increase in the peripheral anterior chamber depth was statistically significant (P less than 0.01).

Angle-closure Glaucoma Complicating Ciliochoroidal Detachment

Acute angle-closure glaucoma complicating ciliochoroidal detachment developed in eight eyes of six patients. The clinical presentation was uniform: extremely shallow central anterior chamber depth, flat peripheral anterior chamber, closed angle, and elevated intraocular pressure (IOP). There were three patients with uveal effusion syndrome, two with posterior scleritis, and one with an arteriovenous malformation. Cycloplegia, along with aqueous suppressants and corticosteroids, successfully resolved the acute glaucoma in all eyes. This rare, secondary glaucoma must be differentiated from primary angle-closure glaucoma, because the treatment is markedly different. Although primary angleclosure glaucoma is treated with miotics and peripheral iridectomy, such therapy may worsen the glaucoma in eyes with angle-closure glaucoma due to a ciliochoroidal detachment.

Acute Closed-Angle Glaucoma After Arteriovenous Fistulas

Unilateral secondary acute closed-angle glaucoma was associated with a ciliochoroidal detachment in two patients. One patient, aged 17 years, had an orbital arteriovenous fistula. The other patient, aged 73 years, had a dural arteriovenous fistula that originated from branches of the right internal maxillary artery. In each patient there was increased intraocular pressure, a moderately shallow central anterior chamber, and a flat peripheral anterior chamber. The ciliochoroidal detachment was postulated to displace the iris-lens diaphragm, resulting in the closed angle. Closure of the orbital fistula in the 17-year-old patient reduced the ciliochoroidal detachment and relieved the glaucoma, but visual acuity was reduced to 20/200. The glaucoma in the 73-year-old patient was relieved with topical instillation of timolol 0.5%, homatropine 5%, and systemic administration of acetazolamide. The fistula closed spontaneously, with relief of other ocular signs of the arteriovenous fistula.

Treatment of a Cyclodialysis Cleft With Argon Laser Photocoagulation in a Patient With a Shallow Anterior Chamber

A 27-year-old man developed a traumatic cyclodialysis cleft with resulting hypotony. He had a flat peripheral anterior chamber, but the chamber was successfully deepened with the help of a Zeiss four-mirror goniolens, and the cyclodialysis cleft treated with argon laser photocoagulation.

Measurements of axial and peripheral anterior chamber depth: accuracy of a photographic method.

The minimum significant (p = 0.05 level) detectable change noted on measuring anterior chamber depth by a photographic method was found to be 7% either way from the mean. The minimum significant change for a peripheral chamber depth 5 mm from the optic axis was found to be 25% either way.

Dimensions of the anterior chamber in pigment dispersion syndrome.

A recently introduced theory of the mechanism of the pigment dispersion syndrome is that pigment granules are released by mechanical contact between the anterior surface of zonular fibrils and the posterior surface of the pigment epithelium of the iris. A photogrammetric study of the depth of the central and peripheral anterior chamber of the iris was carried out in 37 subjects with the pigment dispersion syndrome. These subjects had deeper anterior chambers, particularly in the midperiphery, than could be accounted for by their age, sex, or refractive error. Excessive depth of the anterior chamber is demonstrated to be a risk factor in the pigment dispersion syndrome. Concavity of the midperipheral iris surface was demonstrated in this group of subjects, confirming previous clinical observations and giving additional support to the mechanical theory of pigment dispersion.

Anterior segment configuration correlated with Shaffer's grading of anterior chamber angle.

The central corneal thickness, peripheral corneal thickness, central anterior chamber depth, and peripheral anterior chamber depth were measured from 110 phakic eyes using attachments 1 and 2 to the slitlamp (Haag-Streit). The Shaffer grading system was used for the width of the anterior chamber angle. The results showed that both the average central anterior chamber depth and peripheral anterior chamber depth increased in a linear manner with the Shaffer grading system of the width of the anterior chamber angle. In addition, our "scattergram" showed that each Shaffer grading of the angle width could almost be uniquely determined by the combination of central and peripheral anterior chamber depths. However, the peripheral anterior chamber depth is the best single factor in predicting the Shaffer grading of the width of the anterior chamber angle.

Traumatic cleavage of the chamber angle.

<h3>Introduction</h3> The pathology of tears into the face of the ciliary body after blunt trauma to the eye has been well described in the past.^1-3Treacher Collins in 1892 described the micropathology as a "split into the ciliary muscle in its entire circumference, so that the angle of the anterior chamber was prolonged outwards." (See Fig. 1 from Treacher Collins, 1892.) Wolff and Zimmerman⁴have recently described an association of this postcontusion deformity of the chamber angle with an ipsilateral chronic glaucoma of insidious onset long after the injury. It is the purpose of this report to describe eight cases of blunt trauma which gonioscopically present tears into the face of the ciliary body manifest by a widening and deepening of the peripheral anterior chamber with backward displacement of the iris and the appearance of a characteristic cleft or recess. <h3>Case 1.</h3> —This 53-year-old Caucasian public health