Neil J. Lucchese

Variation in axial length and anatomical landmarks in strabismic patients.

The authors calculated axial length measurements in 185 consecutive patients undergoing strabismus surgery and found a mean measurement of 21.98 +/- 1.59 mm (range, 18.75-25.37 mm). Although significant correlation between axial length, refractive error, and age was found, wide variation was present, which indicates that age and refractive error could not accurately predict axial length. Based on a formula derived from a geometric model to determine the equator-limbus distance, given the axial length, the authors found that the equator had a mean distance from the limbus of 11.56 +/- 1.75 mm (range, 9.10-13.76 mm). Based on the variability found at surgery for the insertion-limbus distance, the number of millimeters of recession of the medial rectus from the insertion that would have been necessary to place it at the equator ranged between 3.5 and 8.5 mm in this series, and for the lateral rectus, 3.5 mm to 7.0 mm. The number of millimeters necessary to recess the lateral rectus to its point of tangency with the globe ranged between 9.5 and 14.4 mm.

Eye Bobbing Associated with Jaw Movement

Two patients were treated for a previously unreported disorder believed to be related to Marcus Gunn jaw-winking. The first, a 9-month-old infant with left congenital blepharoptosis without jaw-winking and with normal ocular motility had an up and down movement of the left globe synchronous with nursing movements of the jaw. The second was a 5-year-old girl with left blepharoptosis, jaw-winking, and left double elevator palsy who had up and down movements of both the left upper lid and the left globe synchronous with chewing. The left globe movements were most prominent in the field of vertical action of the superior rectus muscle and persisted after levator excision and fascia lata sling procedures. The possible etiology of the Marcus Gunn jaw-winking phenomenon is discussed and related to our cases of eye bobbing. The eye bobbing probably is caused by abnormal innervation to the superior rectus muscle produced by jaw movements in a manner analogous to the abnormal stimulation of the levator muscle in jaw-winking. The similar embryologic development and innervation of the levator and superior rectus muscles add credence to this theory.

The efficacy of SimulVue and Unilens RGP aspheric bifocal contact lenses in the treatment of esotropia associated with a high accommodative convergence/accommodation ratio

PURPOSE This was a prospective study assessing the efficacy of the SimulVue bifocal contact lens and the Unilens RGP aspheric multifocal contact lens (Unilens, Largo, Fla.) in the treatment of high accommodative convergence/accommodation (AC/A) esotropia in an adolescent and postadolescent population. METHODS Those patients meeting the inclusion criteria were fit with contact lenses with use of full cycloplegic refraction and later retested by an examiner masked to the previous binocular status. Particular attention was given to the sensory status and the motor fusion of each patient in their bifocal spectacles and then in their bifocal contact lenses. All patients were followed up for at least 6 months after the contact lenses were fitted. RESULTS Five of the six patients demonstrated larger angles of esophoria or tropia at near with the contact lenses than with bifocal spectacles. The only patient who maintained excellent stereopsis in bifocal contact lenses was the one who normalized her AC/A ratio during this study and no longer required a bifocal in her spectacle correction for fusion. The two patients who initially had no stereopsis but good alignment in spectacle correction had a large esotropia at near fixation with bifocal contact lenses. CONCLUSIONS The SimulVue and Unilens RGP aspheric bifocal contact lenses did not adequately treat adolescent patients who had esotropia associated with a high AC/A ratio.

Juvenile myasthenia gravis and amblyopia.

In two girls, 26 and 36 months old, strabismus and blepharoptosis secondary to myasthenia gravis led to amblyopia. The initial symptoms in both patients were blepharoptosis and variable exotropia. Although the amblyopia was successfully treated in one patient, it persisted in the second despite therapy.

Keratitis Associated with Chronic Iridocyclitis

Of a group of 187 patients with chronic iridocyclitis, 16 had keratopathy. Two types of corneal changes were noted: nummular keratitis (four patients; 2.1%) and an opaque band of thickened endothelium that involved the inferior 25% to 50% of the cornea (12 patients; 6.4%). Although not pathognomonic, these corneal changes should suggest the possibility of sarcoidosis in patients with chronic iridocyclitis.

Axial Length Estimation in Strabismic Patients

BACKGROUND Previous studies have indicated that axial length determination is important in strabismic patients for defining the limit for a safe maximum recession of the medial rectus. Also, the response to strabismus surgery may be, in part, a function of axial length. We previously published a formula for predicting axial length based on age and refractive error; however, its accuracy has not been tested in a patient population that is different from the one used to generate the formula. The purpose of this study is to test a formula for estimating axial length, given age and refractive error, in a population that is different from that from which it was generated. METHOD We measured axial length using A-scan ultrasonography in 163 consecutive patients undergoing strabismus surgery. Twenty-nine patients were younger than 18 months of age; 134 patients were between 18 months and 10 years of age. We compared the measured axial length determination with the axial length value estimated by a formula generated from our previous published series. RESULTS For patients younger than 18 months of age, the equation estimated axial length within 0.5 mm in 41.4% of patients, within 1.0 mm in 79.3% of patients, and within 1.5 mm in 93.1% of patients. For patients between 18 months and 18 years of age, the formula estimated axial length within 0.5 mm in 37.3% of patients, within 1.0 mm in 73.1% of patients, and within 1.5 mm in 87.3% of patients. CONCLUSIONS The formula may be useful for the strabismus surgeon in estimating axial length when A-scan ultrasonography is not available in an operating room setting, particularly in congenital esotropes who require larger recessions in small eyes. If, however, A-scan ultrasonography is available, it is preferable to using the formula. The formula is not sufficiently accurate for use for calculating intraocular lens power.

Alternating ptosis after bilateral frontalis muscle suspension for congenital ptosis

PURPOSE To report an unusual response to bilateral frontalis suspension surgery for congenital ptosis. METHODS Case report. RESULTS A 6-year-old child with infantile esotropia and bilateral congenital ptosis received a homologous fascia lata frontalis suspension. After surgery, the patient exhibited an alternating ptosis, caused by alternating unilateral frontalis muscle contraction, which has persisted throughout 3 years of postoperative observation. CONCLUSION Symmetric frontalis muscle activation may not always occur after bilateral frontalis muscle suspension surgery for congenital ptosis. Amblyopia, strabismus, or fixation preference may predispose patients to use unilateral brow elevation, despite bilateral frontalis muscle suspension surgery.