The application of ultrasonic biomicroscopy in the management of traumatic hypotony

Hypotony maculopathy

Hypotony maculopathy, first described in 1954 by Dellaporta, usually occurs after antiglaucomatous surgery or after perforating eye injuries; it is characterized by hypotony associated with fundus abnormalities, including papilloedema, vascular tortuosity and chorioretinal folds. In hypotony maculopathy, the scleral wall collapses inward, resulting in redundancy of the choroid and retina, leading to chorioretinal wrinkling. As the antero-posterior diameter of the vitreous cavity decreases, the very thick perivofeal retina surrounding the very thin foveal retina is thrown into radial folds around the fovea. It has been reported that hypotony maculopathy occurs in up to 20% of cases of glaucoma filtering surgery and has become more common after the introduction of antimetabolites. Young age, myopia, primary filtering surgery, systemic illnesses and elevated preoperative intraocular pressure (IOP) have been found to be associated with hypotony maculopathy. Hypotony maculopathy is treated with procedures designed to elevate IOP, which may reverse the inward scleral bowing and improve visual acuity. The successful treatment of hypotony maculopathy depends on the correct identification of its cause. Once the cause is detected, treatment should be employed as soon as possible because delayed normalization of the IOP may result in permanent macular chorioretinal changes and poor vision. This review will explore the definition, mechanisms, clinical findings and treatment of hypotony maculopathy.

Ultrasound biomicroscopic evaluation of the traumatized eyes

PURPOSE

To review causes for performing an ultrasound biomicroscopic (UBM) examination in traumatized eyes, to present common UBM findings of 109 eyes with a history of ocular trauma and to compare these findings according to the type of the trauma.

MATERIALS AND METHODS

A total of 109 eyes with a history of mechanical ocular trauma, which underwent an UBM examination between December 1996 and April 2002, were evaluated retrospectively. All cases were classified according to the criteria of the Ocular Trauma Classification Group and UBM findings were reviewed. For statistical ana- lyses, chi(2) test and Fisher's exact test were used.

RESULTS

UBM examinations were performed for the evaluation of the zonules before cataract surgery (49.5%), examination of the anterior segment in the presence of media opacities (32.1%), detection of suspected ocular foreign bodies (10.1%) and the evaluation of ocular hypotony (8.3%). In all, 67 eyes (61.5%) had a closed-globe injury, whereas 42 (38.5%) had an open-globe injury. The most common UBM findings in a closed-globe injury were zonular deficiency (64.2%), angle recession (43.3%), iridodialysis (17.9%), and dislocated lens (16.4%). The most common UBM findings in an open-globe injury were zonular deficiency (54.8%), iridodialysis (26.2%), peripheral anterior synechiae (PAS) (26.2%), and iridocorneal adhesion (19%). Among the common UBM findings, the angle recession was significantly higher (P<0.001) in closed-globe injury group and PAS formation was significantly higher (P<0.05) in open-globe injury group.

CONCLUSIONS

UBM is particularly superior to other methods in the evaluation of the zonular status, angle recession, cyclodialysis, and the detection of small superficial and intraocular foreign bodies.