Myotonia congenita with strabismus in a large family with a mutation in the SCN4A gene.

BACKGROUND/AIMS: To determine the genetic basis of myotonia congenita (MC) and strabismus in a large Caucasian family. METHODS: Seven patients making up four generations of a family with MC and strabismus were recruited. All patients had at least one standard ophthalmic examination, including best-corrected visual acuity, refraction, and ocular motility measurements. CLCN1 and SCN4A genes were sequenced and analysed for mutations. RESULTS: Five out of the seven family members were diagnosed with MC by clinical history and electromyography. Ophthalmic history and exam revealed eyelid myotonia and strabismus. All patients with MC were diagnosed with strabismus between the ages of 3 and 6 and required surgical restoration of ocular alignment. Sequencing results revealed a c. 1333G>A; p. Val445Met mutation in the SCN4A gene. CONCLUSION: There are few reports describing eyelid myotonia and strabismus in patients diagnosed with MC. We found significant ocular involvement in a family with a mutation in SCN4A. Future studies may confirm that MC with significant ocular involvement can be used to direct genetic analysis.

Delayed adjustable sutures: a multicentred clinical review.

PURPOSE: To characterise the results of the largest patient series to date undergoing closed conjunctival delayed adjustable suture techniques. METHODS: A multicentre retrospective review of 440 operations (patients aged 10-91 years) by five surgeons at four centres were evaluated for surgical outcomes associated with the delayed adjustable suture technique. RESULTS: 26% (116 of 440) of all patients required postoperative manipulation, with individual surgeon rates ranging from 13% to 56%. The majority of these patients did not complain of diplopia in target gaze and/or had satisfactory cosmetic improvement as evaluated at the 1-3 months follow-up visit (84%). Transient complications included dellen, poor conjunctival appearance, filamentary keratitis, infection, granuloma, exposed suture and corneal abrasion. Serious complications were rare. CONCLUSIONS: This large multicentred series characterises the closed conjunctival delayed adjustable suture technique for the correction of strabismus. It may present some significant advantages to more traditional adjustable suture techniques.

A multicentre randomised double masked clinical trial of a new formulation of topical cysteamine for the treatment of corneal cystine crystals in cystinosis.

AIM: To evaluate the safety and efficacy of a new topical cysteamine formulation, stable at room temperature, for the treatment of corneal cystine crystals in cystinosis. METHODS: 20 study subjects were enrolled in the safety study and 16 in the efficacy study. Both studies were randomised and double blind. The primary outcome for the safety study was the occurrence of predefined serious adverse reactions over 6 months and for the efficacy study the reduction of corneal cystine crystal score (CCCS) by 1.00 or more units on photographs graded by a reading centre using a standardised protocol. RESULTS: No study subject developed any serious adverse reactions. In the efficacy study, 47% of eyes receiving the standard formulation experienced a reduction in the CCCS of >/=1.00 after 1 year, while 7% of eyes on the new formulation experienced such a decrease (p=0.04). CONCLUSION: Although no serious adverse reactions were observed with either formulation, the new formulation was not as effective as the standard formulation.

Marked variability amongst pediatric ophthalmologists in designating the diagnostic gaze position angles in ocular motility evaluations.

BACKGROUND: Management of strabismus relies on accurate evaluation of binocular alignment in standard gaze positions. In 1962, Stuart & Burian noted that, without adopting a standard routine, "measurements of various patients could not be compared, and there will be considerable difference in measurement from one examination to another and by different examiners" (1). Diagnostic position gaze angles are not routinely measured. Is this important? SUBJECTS AND METHODS: Subjects were 82 volunteer experts recruited from attendees at the 1998 American Association for Pediatric Ophthalmology and Strabismus (AAPOS) scientific meeting. One author served as examinee for all testing. The actual head posture was measured for the expert designated primary position, right and left gazes, head tilts and up- and downgazes using the CROM device. The examinee fixated at a six meter distance accommodative target. Examiners were asked to mimic their office routine. Eighty-two subjects ranging from 29 to 69 years of age, consisting of 24 females and 58 males were recruited. Sixty-nine were pediatric ophthalmologists, 7 orthoptists, 4 international members and 2 members in training. Eight subjects also underwent re-testing. Years in practice averaged 11.5. RESULTS: Range of head posture measurements: For "Horizontal Gaze": 10 to 50 degrees; For "Vertical Gaze": 4 to 58 degrees; For "Head Tilts": 20 to 50 degrees. There was no substantial difference between initial and repeat measurements. CONCLUSION: There is a surprisingly high degree of variability amongst expert observers in defining standard gaze positions. These results may explain some of the inconsistent outcomes noted in the strabismus literature. The implication for transferring data from publication to practice and in designing multicentered protocols is concerning. Without defining and maintaining a standard for binocular alignment measurements, comparison between studies and examiners is not possible.

A new objective digital computerized vision screening system.

PURPOSE: Fewer than 40% of children in the crucial younger-than-4 age group are evaluated for visual problems by pediatricians. This is due to impracticality from either a clinical or practice efficiency standpoint. Current photoscreening methods require trained readers and suffer from significant subjectivity and interobserver variability. We report a cross-sectional, double-masked study using new digital imaging with objective, automated, computerized image analysis. METHODS: Two-hundred six children aged 9 months to 16 years were prospectively studied in a University-based pediatric ophthalmology practice. Images were taken by volunteers with a modified digital camera which, when downloaded, were analyzed within 35 seconds by new image analysis software. The analysis was compared to a masked review of a complete pediatric ophthalmic exam. RESULTS: Overall agreement between physician and the objective computerized analysis was 86.9%. Positive predictive value was 91%, sensitivity was 89%, and specificity was 83%. CONCLUSIONS: This automated digital imaging screening system eliminates human bias and provides accurate and immediate results. The system requires no special expertise.

Adjustable horizontal rectus recession surgery for disparate distance-near ocular deviations.

Strabismic deviations which display incomitance changing from distance fixation to near fixation are the result of many disturbances of both the supranuclear and infranuclear ocular motor system. This report details the surgical treatment and outcome of 6 patients with disparate distance-near deviations due to different etiologies. The surgical procedure involves recessing all four horizontal recti on both eyes using the adjustable suture technique. The approach to surgery consisted of operating on the vergence angle with the larger deviation with a bilateral lateral rectus recession (BLREC) or a bilateral medial rectus recession (BMREC) and simultaneously operating on the smaller vergence angle, treating the total induced deviation with the bilateral recession not used first (remaining BLREC or BMREC). All patients had a significant decrease in their distance-near disparity, increased horizontal comitance, normalization of their accommodative convergence to accommodation ratios, and resolution of diplopia. A four horizontal recti muscle, adjustable suture recession is another technique that can be added to the treatment regimens for distance-near disparity strabismic syndromes.

The use of hyaluronic acid during adjustable suture surgery.

We prospectively studied the force required to move an extraocular muscle after adjustable suture surgery with and without the perioperative use of hyaluronic acid (Healon). The 15 muscles that received hyaluronic acid averaged 15.0 g of force to move the muscle 2.0 mm which was significantly different than the average force of 36.15 g required for the 13 control muscles. The decreased force required to adjust the muscle along with potential antiinflammatory properties of hyaluronic acid make this a useful adjunct during adjustable suture surgery.

The intraoperative oculocardiac reflex as a predictor of postoperative vaso-vagal responses during adjustable suture surgery.

1. Adjustable suture surgery has become a popular method of strabismus correction in cases in which results are less predictable, such as reoperations, thyroid ophthalmopathy, and blind eyes. 2. Some adjustable strabismus surgery patients experience significant vaso-vagal responses (V-VR) during postoperative adjustment. 3. A positive intraoperative oculocardiac reflex under general anesthesia during strabismus surgery is highly predictive of a postoperative V-VR during planned adjustment.

The visual-evoked response in infants with central visual impairment.

We studied ten children with central visual impairment with a known neurologic defect and an abnormal visual-evoked response who had results of repeat electrophysiologic testing evaluated at the Children's Hospital of Philadelphia from December 1989 through July 1991. Central visual impairment is defined as poor visual function with a normal anterior visual pathway. Age at first examination ranged from 5 to 48 months with a followup of two to 31 months. Repeat visual-evoked response testing showed improvement in seven patients and no change in three. Grating acuity as measured by the Teller acuity card procedure, performed in nine of ten patients, improved in seven, showed no change in one, and declined in one. We found a potentially favorable prognosis for those infants with central visual impairment, despite an initially abnormal visual-evoked response. We used a clinical approach to this disorder to improve diagnostic categorization and prognostic capabilities in central visual impairment.

The intraoperative oculocardiac reflex as a predictor of postoperative vaso-vagal responses during adjustable suture surgery.

Adjustable suture surgery has become a popular method of strabismus correction in those cases in which results are less predictable, such as reoperations, thyroid ophthalmopathy, and blind eyes. Complications related to adjustable strabismus surgery are, in general, no different than those related to standard surgical techniques. We noticed a subgroup of patients who experienced significant vaso-vagal responses (V-VR) during postoperative adjustment and sought to discover a method of identifying these patients prior to adjustment. Sixty patients were studied prospectively from July 1991 to July 1992. All patients had surgery under general anesthesia and were adjusted 24 hours later. A positive oculocardiac reflex (OCR) occurred when a 10% or greater intraoperative change in heart rate was associated with traction on an extraocular muscle. A positive V-VR postoperatively consisted of one or more subjective findings (dizziness, light-headedness, nausea, or body temperature changes), and two or more objective findings (10% or greater change in heart rate, hypotension, pallor, diaphoresis, vomiting, disorientation, or loss of consciousness). Variables studied for predictive value included OCR, age, sex, strabismus type, previous surgery, muscle adjusted, and systemic disease. Twenty-five patients (41.6%) had a positive V-VR during adjustment. Twenty-seven patients (45%) had a positive OCR. Eighty-five percent of patients with a positive OCR and 9% of patients with a negative OCR had a positive V-VR. Younger patients were also more likely to have a positive V-VR. A positive intraoperative OCR under general anesthesia during strabismus surgery is highly predictive of a postoperative V-VR during planned adjustment.

Orbital wall infarction in sickle cell disease: MR evaluation.

Orbital wall infarction in a patient with sickle cell disease can present with periorbital swelling and subperiosteal collection and thus can mimic infection on CT. However, MR not only provides excellent morphologic information but, by characterizing the nature of the collection as containing blood, and by identifying bone marrow abnormality, can lead to the diagnosis of orbital wall infarction.