Evaluation and Prism Management of Divergence Insufficiency Esotropia.

An esodeviation that is greater at distance than near in an adult patient requires a full sensorimotor exam to rule out any cofounding neurological conditions. Many etiologies are described in the literature to cause an esodeviation that is greater at distance than near in adult patients and some exist in conjunction with a neurological condition. However, many adult patients present to the adult strabismus clinic with no other findings on exam and have a purely benign divergence insufficiency esotropia. A review of the literature on divergence insufficiency reveals a few attempts of classifying these entities, but none have been completely accepted.Recently benign non-neurological divergence insufficiency esotropia has been described as a resulting condition due to a mechanical etiology. Currently, the literature only describes a couple of different etiologies.Regardless of the etiology, these patients are quite symptomatic and present to the adult strabismus clinic with various complaints and require a thorough examination. The primary focus of the exam is to first rule out the need for further neurological work-up, but secondly, to also determine the best treatment option for the patient. To determine the best treatment plan, a thorough evaluation, including a sensorimotor exam with proper testing, can help. Many of these patients do very well with base-out prism management; however, some have decompensated to a larger angle and prefer surgical intervention. However, the focus of this paper will be on nonsurgical prism management of patients with divergence insufficiency that is not associated with any neurological disorder.

Fresnel prism use among orthoptists.

PURPOSE: To better understand current uses of Fresnel prisms. METHODS: A seventeen-question survey was completed by members of the American Association of Certified Orthoptists (AACO). RESULTS: Surveys were emailed to 211 orthoptists with a 36% response rate (n = 76). Prisms are used preoperatively to determine the surgical angle for 72% of respondents, 94% use prisms for postoperative misalignment. Prisms are used for incomitant deviations by up to 96% of respondents. The greatest patient objection to Fresnel use is reduced vision and distortion, not diplopia out of primary position. Of orthoptists surveyed, 99% use Fresnel prisms for near-distance disparity, 36% splitting prisms for upper and lower segments, and 40% encourage separate spectacles for near and distance. When deciding to grind prism, 66% wait more than one month. Ninety-nine percent of orthoptists use Fresnel prisms with adults, 67% use them with children. When correcting vertical and horizontal deviations, 70% of orthoptists rotate a prism over one lens. CONCLUSION: Fresnel prisms have a wide use among North American certified orthoptists, including use with pediatric patients. Incomitance is not a contraindication to Fresnel use. Orthoptists prefer rotating one prism to bilateral Fresnel prisms.