Volume 14 Number 1 / February 2010 70D (mean 53D). Vision in each eye ranged from 20/120 Snellen to light perception, except one patient with Usher syndrome had grossly restricted visual fields and vision of 20/40 and 20/200. The etiology was retinitis pigmentosa in 5 patients, 3 had cone dystrophy, 2 were high myopes. Other etiologies included CMV retinitis in both eyes secondary to HIV, bilateral optic atrophy post craniopharyngioma and cortical visual impairment. All patients were unable to actually see their strabismus but were aware of its presence from family members and friends, and wished improvement. Eight patients underwent botulinum toxin injections; 2 of these then proceeded to surgery. A total of 7 patients had surgery. Postoperative angles ranged from 6D to 25D of esotropia. Five patients continued with maintenance toxin. Follow-up ranged from 3 months to 15 years. Conclusions: This is the first report of patients with bilaterally severely reduced vision requesting treatment for strabismus that they were unable to see for themselves. 056 Vessel Width in Type 1 ROP: Zone I vs Zone II. Emily A. DeCarlo, Gui-shuang Ying, Graham E. Quinn, Diego Fiorin, Alfredo Ruggeri, Karen Karp, Monte D. Mills Introduction: Type 1 retinopathy of prematurity (ROP) as defined by ETROP encompasses disease in zone 1 with or without plus disease and zone II with plus disease. Our hypothesis is that the width of posterior retinal vessels in eyes with Type 1 ROP do not differ when the retinopathy occurs in zone 1 compared to zone 2. Methods: Right eyes of 32 patients identified as Type 1 ROP were included. Images were captured just prior to laser photocoagulation using an NM200D camera (Nidek Inc., Gamagori, Japan). A computerassisted algorithm, ROPnet, developed by D Fiorin and A Ruggeri, University of Padua, was used to measure tortuosity, width, and standard deviation of width of up to 8 vessels from each image. Vessel parameters were compared between the group of Type 1 eyes with zone 1 ROP and Type 1 eyes with zone 2 ROP using two-group t-tests. Results: Of these 32 eyes analyzed, Type 1 ROP was present in zone 1 in 13 eyes and in zone 2 in 19. Gestational age and birth weight were similar between the two groups. As expected, the post-menstrual age at the time of the photographs was significantly different, since Type 1 disease in zone 1 presents earlier than in zone II. All of the 19 zone 2 eyes had plus disease compared with 7 of the 13 zone 1 eyes. The width of venules and arterioles was not significantly different between the Type 1 ROP eyes in zone 1 and in zone 2. Conclusions: Using the digital vessel analysis program ROPnet, width measurements of posterior retinal vessels does not differentiate Type 1 ROP in zone 1 from Type 1 ROP in zone 2. This suggests that vessel width of the group of eyes with Type 1 ROP in zone 1 is not different from the group of eyes with Type 1 ROP in zone 2 using only posterior pole images from the NM200D camera. 057 Anatomy of superior oblique (SO) palsy in primate model: rapid overall atrophy with relative sparing of orbital layer. Joseph L. Demer, Vadims Poukens, Howard Ying, X. Shan, J. Tian, David S. Zee Introduction: We employed magnetic resonance imaging (MRI) and whole orbital histology to study effects of trochlear neurectomy on the monkey SO muscle. Methods: Five normal adult macaque monkeys underwent unilateral or bilateral lesion by removal of 10 mm of subarachnoid trochlear nerve 5-72 weeks before sacrifice. Lesioned animals exhibited typical strabismus. Orbits were imaged bilaterally by MRI, embedded whole, serially sectioned, and stained with Masson trichrome. We compared whole muscle and individual fiber cross sections in ipsilesional and normal SO muscles throughout the orbit.
Journal of AAPOS
e15 Results: Both MRI and histology showed highly significant (p \ 0.000001) , persistent atrophy of the SO belly in all animals complete within 5 weeks post-lesion. Atrophy of 30% to 60% was most severe in global fibers and varied along the SO length, relatively sparing orbital fibers, particularly late. Affected SO bulk shifted anteriorly, consistent with elongation of the muscle belly, and preserving SO volume even after denervation. Microscopy showed ipsilesional fibrosis of all trochlear nerve branches. In one animal, scattered clusters of hypertrophic global layer fibers extending the entire SO length suggested reinnervation from small nerves traveling from the orbital layer. Discussion: MRI detects, and histology confirms, striking but partial and persistent SO belly atrophy fully established by 5 weeks after acquired SO palsy in monkey. This atrophy is mainly in the oculorotary global fibers, relatively sparing orbital fibers that insert on the SO sheath and pulley system. Residual or re-innervating fibers do not travel in the trochlear nerve. Denervated SO muscles elongate as they thin. Conclusions: MRI can confirm partial SO atrophy that becomes complete shortly after acquired SO palsy onset, supporting use of MRI in clinical diagnosis of SO palsy. More extreme SO size reduction probably indicates congenital SO hypoplasia. Elongation of denervated SO muscles would explain ''floppy'' tendons observed at surgery for SO palsy, but would not indicate that the palsy was congenital. 058 Pediatrician experience with the Plusoptix vision screener: An observational clinical trial. Sean P. Donahue, Niraj R. Nathan, Kathryn E. Allen Introduction: To determine the usefulness of the Plusoptix photoscreener in the pediatric office. Methods: Four-hundred fifty seven children were screened using the Plusoptix screener with the manufacturer's referral criteria in five pediatric practices. Referred children received a comprehensive ophthalmic examination. Follow-up information was determined by chart review at the individual pediatric practices or by review of electronic medical record at our institution. Screening results were compared using AAPOS Vision Screening Committee amblyogenic factors and were also evaluated using other proposed referral criteria for the Plusoptix instrument. Results: Of the 457 children screened, 94 were referred by the Plusoptix screener (21%). Only 19% of children had documented follow-up, and the PPV was 27% in this group. Applying the criteria proposed by Arthur1 (Anisometropia $1.5 D, Hyperopia .3.5 D, Myopia .3.0 D, Astigmatism .1.5 D, Anisocoria . 1 mm) decreased referral rate. Modifying the Arthur criteria (increase cylinder to .2.0 D) lowered the referral rate to 10%. Conclusions: The manufacturer's criteria led to an excessively high referral rate and low PPV. The referral criteria proposed by Arthur led to a high referral rate, while the modified Arthur criteria significantly reduced referral rate, suggesting that the Plusoptix screener overestimates astigmatism. Confirmation of follow-up was found in only a minority of referred patients' charts, indicating a concerning problem of low follow-up rates and/or low confirmation of follow-up by the pediatric practices, which has been demonstrated in other studies evaluating vision screening in the pediatric home. 059 Reduced health-related quality of life correlates to diplopia severity in patients with thyroid eye disease. Noha S. Ekdawi, Elizabeth A. Bradley, Sarah R. Hatt, David A. Leske, Jonathan M. Holmes Introduction: Diplopia may be a specific cause of reduced health-related quality of life (HRQOL) in thyroid eye disease (TED). We evaluated the impact of diplopia on HRQOL in patients with TED.