CT-Dacryocystography Findings in a Case of Atonic Lacrimal Sac.

Abstract

A female of age 42 years presented with a history of epiphora with discharge in the OD of 18 months duration. On examination, there was a palpable swelling noted in the lacrimal sac fossa region on the right side with raised tear meniscus height (Fig. A). Compression of the palpable lacrimal sac reduced the swelling without any regurgitation from the puncta, and the patient reported fluid emptying into the nasal cavity. Irrigation from the upper puncta for the right side revealed increasing lacrimal sac swelling with increasing resistance to irrigation. On compressing the enlarged lacrimal sac postirrigation, the retained fluid could again be emptied in the nasal cavity, which was also reported by the patient. Post compression, the lacrimal sac swelling returned to the preirrigation state. Clinically, in view of these findings, intermittent sac dilatation, and patent lacrimal drainage system, it was not considered to be a mucocele. The OS was asymptomatic with a patent lacrimal drainage system. A CT study revealed a right-sided expanded and deep bony lacrimal sac fossa as compared with the left, suggestive of a chronic pathology (Fig. B). Three-dimensional CT-dacryocystography was performed using the nonionic, water-soluble contrast medium (Iohexol, 755 mg/mL), diluted to 1:10 concentration with normal saline and injected slowly using the lacrimal cannula in the lacrimal drainage system. The 3-dimensional reformatted image demonstrated an irregularly dilated right lacrimal sac, mostly limited to its fundus and upper half of the body without a discernible outpouching. There was a minimal dilatation of the right proximal nasolacrimal duct (Fig. C). Coronal reformatted image shows a dilated right lacrimal sac with patent nasolacrimal duct (Fig. D). Parasagittal reformatted image showed the dye filling the length of the nasolacrimal duct system, corroborating with the clinical findings (Fig. E). Atonic lacrimal sac is a distinct clinical entity with typical clinical features and is usually seen in adults with chronic sac dilatation without a coexisting nasolacrimal duct obstruction. Although orbicularis weakness or pump failure can additionally contribute to its development, the primary pathology appears to be the loss of tone of the lacrimal sac walls themselves. The etiopathogenesis of an atonic sac is obscure, and dacryocystorhinostomy is usually curative. Clinical photograph showing a mild swelling in the right lacrimal sac region with elevated tear meniscus height (panel A). CT image, coronal cuts, showing a right-sided expanded and deep bony lacrimal sac fossa (panel B). Three-dimensional (3D) reformatted image (panel C) and coronal image (panel D) showing dilated right lacrimal sac and proximal nasolacrimal duct (NLD) and parasagittal reformatted image demonstrating the passage of dye along the NLD (panel E).