Comparison of VEP Values in Acquired Esotropia with Exotropia

PURPOSE: To investigate about the influence of acquired strabismus, its angle and stereopsis on visual evoked potential (VEP). METHODS: This study included 30 accommodative esotropes and 30 intermittent exotropes aged 5 to 10, who had not undergone strabismus surgery. Partially accommodative esotropes were excluded. Angle of deviation, stereopsis, and refractve error were measured in all subjects. The values of VEP to monocular and binocular pattern stimulation were recorded. Statistical significances were tested by t-test and Kruskall-Wallis test. RESULTS: In intermittent exotropes, the P100 amplitude of deviating eye was smaller than that of normal eye in the test with 8 X 8 and 16 X 16 check size (p<0.05). There was no significant difference in accommodative esotropes. The P100 latency of binocular VEP using 16 X 16 check size was significantly short in intermittent exotropes, comparing to the normal eye. Angle of deviation and stereopsis did not influence on VEP. CONCLUSIONS: Acquired strabismus occurring beyond the end of the visual critical period can influence on VEP, but angle of deviation and stereopsis could not.

The Accuracy of Axial Length Measurement Using Partial Coherence Interferometrys

PURPOSE: IOLMaster(R), a non-contact device using partial coherence interferometry, serves as a new optical method for axial length determination. The accuracy of this device was analyzed by comparing the measurements from IOLMaster(R) and A-scan. METHODS: We measured the axial lengths in 150 eyes of 80 patients with IOLMaster(R) and A-scan. Then, we examined the difference of measurements between the IOLMaster(R) and A-scan according to the patients' age, refractive error, type of cataract, and existence of cataract. RESULTS: Axial length could not be measured with IOLMaster(R) in 12 eyes, which all had severe cataract. The measurements from IOLMaster(R) in both, the cataract group and the normal group, resulted 0.02mm longer than those from A-scan, but did not differ significantly (p>0.1). Also, there was no statistical difference of measurements between IOLMaster(R) and A-scan according to the patients' age, refractive error, and types of cataract (p>0.05). CONCLUSIONS: Axial length measurement with IOLMaster(R) shows no significant difference from A-scan measurement. Therefore, IOLMaster(R) can be a new clinical method of axial length measurement except for cases of a severe cataract.

The Effect of Anterior Chamber Irrigation with OcuLarsol(R) on the Corneal Endothelial Cells

PURPOSE: To verify the stability and effect of OcuLarsol(R), which was newly developed for irrigating solution, by evaluating influence on cornea. METHODS: In vivo study group, after an irrigation and aspiration instrument was put into rabbit's anterior chamber: one eye was irrigated with OcuLarsol(R) for 15 minutes, and the other eye with the balanced salt solution (BSS(R), Alcon, USA). After the operation, corneal changes were observed for a week. In vitro study group, after enucleating of rabbits' eyeballs, corneas were mounted in a dual chambered specular microscope and perfused with glutathione bicarbonate Ringer's solution (GBR) for one hour: one cornea of the pair was perfused with OcuLarsol(R) and the other cornea was perfused with BSS(R) for 2-3 hours. After perfusion, corneal swelling rates and endothelial permeability were measured. RESULTS: In vivo study group, central corneal thickness measurement and endothelial cell count showed that there was no significant difference between the two groups on the day of operation, and 1st, 3rd and 7th day after the operation (p>0.05). Corneal endothelial observation with Alizarin red S, HandE stain, and scanning electron microscope detected no difference in cell shape and density. In vitro study group, corneal swelling rates and endothelial permeability showed no significant difference between OcuLarsol(R) and BSS(R) group and transmission electron microscope showed endothelial cells with normal organelles in all groups. CONCLUSIONS: There was no significant difference between the two irrigating solutions, BSS(R) and OcuLarsol(R), in terms of effect and side effects.

A Case of Bilateral Duane's Retraction Syndrome Associated with Goldenhar's Syndrome

PURPOSE: Duane's retraction syndrome is a congenital eye movement disorder caused by innervational disturbance. It is rare that Duane's retraction syndrome is associated with Goldenhar's syndrome which shows systemic congenital malformations. We report a case of bilateral Duane's retraction syndrome associated with Goldenhar's syndrome, which was treated with strabismus surgery and excision of epibulbar lipodermoid. METHODS: A 14-month-old boy with exotropia showed severe limitation of adduction, mild limitation of abduction, globe retraction and palpabral fissure narrowing on attempted adduction in both eyes. He also had a diffuse small epibulabar mass under the lateral conjunctiva in the left eye. The angle of exodeviation was 45PD on alternate prism cover and uncover test. He had had cleft lip, multiple skin tags on the face and preauricular appendages since birth and undergone an operation for these abnormalities at age of 4 months. Bilateral 7.5mm recession of the lateral recti and excisional biopsy of epibulbar mass of the left eye were performed. RESULTS: A case of Duane's retraction syndrome associated with Goldenhar's syndrome was found. The patient obtained orthophoria in his primary gaze after bilateral recession of lateral recti. The epibulbar mass was consistent with lipodermoid on pathologic examination.