Volume 16 Number 1 / February 2012 e17

Results: Of 571 patients with NLDO, 115 had amblyopia risk factors:109 patients had amblyogenic refractive errors, 3 patients had stra-bismus alone, and 5 patients had a combination of the two. Themost frequent refractive error was astigmatism in 56 patients. 33 pa-tients had anisometropia, and 26 of those had unilateral NLDO. Of the26 patients with unilateral NLDO 20 patients (P5 0.0001) had the ob-struction on the same side of the higher refractive error.Discussion: The children in our study had a higher prevalence of am-blyopia risk factors than the general population. Our results weresimilar to another study done in Pennsylvania. It has been postulatedthat the abnormally increased tear film might cause distortion of thecorneal refractive surface. It is unclear whether these patients willdevelop amblyopia in the future or they will reach emmetropizationafter successfull treatment of their NLDO.Conclusions: We recommend that children who present with NLDOreceive a comprehensive eye examination, including a cycloplegicrefraction.

062 Comparison of stratus and spectralis optical coherencetomography (oct) in pediatric glaucoma evaluation. Fatema F.Ghasia, Sharon F. Freedman, Anand Rajani, Sandra Holgado,Sanjay Asrani, Mays El-dairiIntroduction: The new generation spectral-domain (SD)-OCT cantrack eye movements and has faster acquisition and higher resolu-tion than time-domain (TD)-OCT. SD-OCT has proven helpful in adultswith glaucoma and may be valuable in pediatric glaucoma.Purpose: To compare the peripapillary retinal nerve fiber layer (RNFL)and macular volume (MV) in eyes of normal children, glaucoma sus-pects and those with glaucoma, using both SD-OCT (Spectralis,Heidelberg-Engineering, Germany) and TD-OCT (OCT-3, Carl-Zeiss-Meditec, Dublin, CA).Methods: The RNFL and MV were compared using SD-OCT in nor-mals, glaucoma-suspects [cup-to-disc-ratio(C/D) . 0.5 and IOP \21 mmHg], mild glaucoma (C/D\ 0.5 and IOP . 21) and advancedglaucoma. A subset of subjects had both SD-OCT and TD-OCT mea-surements on the same day. Children with neurologic disorders, re-fractive error of . � 5D, pseudophakia, prematurity, and poorscan quality were excluded.Results: Included were 60 eyes (57 subjects), mean 12.5 � 4 yearsSD-OCT measurements of average RNFL thickness and MV differedamong normals (n 5 22), glaucoma suspects (n 516), mild (n 512)versus advanced (n 5 7) glaucoma (RNFL:105 � 10,100 � 7,98 � 8vs 51 � 14 mm, respectively, MV: 8.8 � 0.4,8.6 � 0.3,8.9 � 0.4 vs 7.7� 0.4 mm3, resp. ANOVA P \ 0.001). Measurements from same-day TD-OCT and SD-OCT in 35 eyes correlated linearly between the2 machines (RNFL R2 5 0.88,P\ 0.05; MV R2 5 0.58, P\ 0.05). Onaverage, TD-OCT RNFL measurements were thicker by 10 � 9 mmand MV was less by 1.4 � 0.4 mm3 compared to SD-OCT for allgroups. 3 of 7 (45%) eyes with advanced glaucoma had unreliableTD-OCT but reliable SD-OCT.Discussion: SD-OCT measurements of RNFL&MV correlated withthose of TD-OCT, but values were not interchangeable. SD-OCTwas easier to obtain than TD-OCT for some children.Conclusions: SD-OCT correlated with the severity of glaucoma inchildren, and may be valuable in their assessment.

063 Improved technique for simultaneous correction ofstrabismus and ptosis in selected patients with third nerve palsyand aberrant regeneration. Ahmed M. Gomaa, Monte Del MonteBackground/Purpose: Treatment of patients with third nerve palsygenerally requires both strabismus surgery on the palsied eye and

Journal of AAPOS

ptosis surgery. The authors investigated an improved approach totreatment of patients with third nerve palsy and significant aberrantregeneration. A recess/resect procedure was performed on the con-tra lateral normal eye to use the misdirection to correct the ptosis aswell as the strabismus.Methods: Five patients (3 males, 2 females) were identified with thirdnerve palsy and significant aberrant regeneration in which the ble-pharoptosis resolved on adduction. Age ranged from 9 to 37 years.All cases were traumatic or compressive. A contralateral lateral rec-tus recession and medial rectus resection were performed to correctboth the exotropia and blepharoptosis.Results: The blepharoptosis was eliminated or significantly improvedin all the 5 cases with a single procedure and the postoperative angleof deviation was reduced to within 8 prism diopters of orthotropia inprimary gaze. No additional surgery was required.Discussion: The classic treatment of these cases involves treatingexodeviation by ipsilateral recess- resect or transposition of the rec-tus or oblique muscles followed by a separate ptosis procedure tominimize the blepharoptosis. We report an improved technique tocorrect both the blepharoptosis and exotropia in one-step surgeryby contralateral muscle surgery taking advantage of the aberrantregeneration. Examination techniques to aid in patient selectionand surgical dosing will be discussed.Conclusions: While reported by the author previously as a case re-port, this larger case series demonstrates that contralateral musclesurgery is an excellent option for the combined correction of blephar-optosis and strabismus in selected cases of third nerve palsy withaberrant regeneration.

064 Anisometropic refractive errors occur more frequently in lefteyes than right. Benjamin P. Hammond, Ge Wen, Rohit Varma,Kristina Tarczy-HornochBackground/Purpose: A laterality bias in the development of ambly-opia has been reported, with the left eye being affected more fre-quently. Possible explanations proposed for this include lateralityin the development of anisometropia, microtropia, or ocular domi-nance. The present study evaluates the laterality of amblyogenic an-isometropia in the Multi-Ethnic Pediatric Eye Disease Study(MEPEDS).Methods: The laterality of amblyogenic anisometropia was deter-mined for all patients enrolled in MEPEDS, a population-based studyof over 9,000 children aged 6 to 72 months. Refractive error wasdetermined by cycloplegic autorefraction. Amblyogenic anisometro-pia was subdivided into hyperopic, myopic, and cylindrical subtypes.The laterality of anisometropic amblyopia among children old enoughto perform optotype acuity testing was determined.Results: Hyperopic anisometropia (spherical equivalent difference$1 D) involved the left eye 65% of the time (P 5 0.0006). Therewere 4 cases of amblyogenic myopic anisometropia (spherical equiv-alent difference $3 D), all of which involved the left eye. Cylindricalanisometropia (cylinder difference$1.5 D) did not demonstrate a sta-tistically significant preference. Anisometropic amblyopia demon-strated a trend for increased left eye prevalence at 55%, thoughthis was not statistically significant.Discussion: Hyperopic anisometropia, the most common cause ofanisometropia in young children, occurs more frequently in the lefteye. While the etiology of this phenomenon is unclear, it may explainthe laterality bias of anisometropic amblyopia reported by multipleauthors.Conclusions: Hyperopic anisometropia develops more frequently inthe left eye than the right.