ABSTRACT
Background: We compared the wave amplitude of visually evoked potential [VEP] between patients with esotropic and anisometropic amblyopic eyes and a normal group
Methods: The wave amplitude of VEP was documented in 2 groups of persons with amblyopia [15 with esotropia and 28 with anisometropia] and 1 group of individuals with normal visual acuity [n, 15]. The amplitude of P100 was recorded monocularly with different spatial frequencies
Results: Our statistical analysis revealed that the wave amplitude in the 2 groups with amblyopia was significantly decreased compared to that in the normal group [P<0.001]. There was a significant difference regarding the amplitude in high spatial frequencies in both high- and low-contrast conditions between the groups with esotropia and anisometropia and the normal group [P<0.001]. There were also significant differences in large check-size stimuli and low-contrast condition between the amblyopic groups with esotropia and anisometropia and the normal group [P=0.013 and P=0.044, respectively]. In large check-size stimuli and high-contrast condition, a significant difference was indicated only in the comparison between the esotropic amblyopic eyes and the normal eyes [P=0.036]
Conclusion: The wave amplitude parameter of VEP was influenced by both types of amblyopia, but it seems that this parameter was more sensitive to esotropic amblyopia than anisometropic amblyopia. This outcome may reflect a non-parallel pattern of cortical responses in the comparison of the 2 types of amblyopia with each other and with the control group, which may be beneficial for the diagnosis and treatment of amblyopia
ABSTRACT
Background: Inferior rectus recession, Knapp procedure, partial tendon transposition, and combined procedure are different surgical procedures in the management of monocular elevation deficiency [MED]. Only a few studies have been published on the management of this problem. In this study, we report our experience with patients with MED focusing on the indications and types of surgery in the south of Iran
Methods: In this case series, a computerized database review on 4773 patients with strabismus was performed and 18 patients diagnosed as having MED who had undergone strabismus surgery were enrolled
Results: Of the 18 patients, 13 had only hypotropia and 5 had horizontal deviation as well. Preoperative vertical deviation was between 15 and 60 prism diopter [mean +/- SD=25.8 +/- 10.7 PD]. Fourteen patients had positive forced duction test on elevation. Seventeen patients had ptosis twelve of them had true ptosis and the remaining 5 had pseudoptosis]. The mean postoperative follow-up was 24.4 months. Four patients underwent Knapp procedure, 12 patients underwent inferior rectus recession, and for 2 patients a combined procedure was performed. The mean postoperative hypotropia was 6.1 +/- 7.9 PD. Twelve out of the 18 patients were corrected to within five PD of orthophoria and no one was found with overcorrection
Conclusion: Although MED is etiologically multifactorial, satisfactory surgical results can be achieved by judicious selection of the surgical technique based on the results of the forced duction test
ABSTRACT
To evaluate the association between fixation preference [FP] and amblyopia in strabismic patients. This study includes 50 patients with horizontal, vertical or mixed strabismus of at least 10 prism diopters. Best-corrected monocular visual acuity [VA] was measured using Snellen E-chart and the presence of amblyopia was determined accordingly; FP was evaluated and graded from 0 to 3. Of 50 patients, including 27 female and 23 male subjects, 29 [58%] patients had FP but 18 [36%] subjects were truly amblyopic. Overall, the sensitivity and specificity of FP for detection of amblyopia was 88.9% and 59.4% respectively. The positive predictive value [PPV] and negative predictive value [NPV] were 55.2% and 90.5% respectively. Sensitivity, PPV and NPV were significantly higher in esotropic as compared to exotropic patients. Strong monocular FP was correlated with more than 3 lines of interocular difference [IOD] in visual acuity [P=0.001]. Although FP is not an ideal method for diagnosis of strabismic amblyopia, it has high sensitivity, PPV and NPV in esotropic patients and in subjects with more than 3 lines of IOD in VA
Subject(s)
Humans , Male , Female , Fixation, Ocular , Strabismus , Visual AcuityABSTRACT
Recession is the main surgical procedure in correction of eye deviation in Duane's syndrome. We evaluate the efficacy of botulinum toxin injection in the treatment of this type of strabismus instead of surgery or before it. Three patients with Duane's syndrome type I and one patient with Type II were selected at Poostchi eye clinic from patients who diagnosed primarily and had not any eye surgery before. Botulinum toxin [Dysport[TM], 10 IU] was injected into medial or lateral rectus muscles under general [2 patients] or local [2 others] anesthesia. Amount of deviation, leash phenomenon and limitation of movements were measured pre injection and 72 hours, 1, 4, 12 and 24 weeks postinjections and the results were compared. The amount of deviation was decreased between 8-35 PD at 24 weeks postinjection. No significant change was observed in limitation of movement but leash phenomenon improved in 3 patients. Injection of botulinum toxin in Duane's syndrome will decrease the amount of deviation and leash phenomenon; however, surgical intervention maybe necessary for residual deviation or globe retraction