The subjectivity of objective evaluation of torsion on fundus photographs by practicing strabismologists

Purpose: To assess the variability of assessing the ocular torsion on fundus photographs among strabismus surgeons. Methods: This was a prospective, noninterventional, clinical trial involving 16 trained and experienced squint surgeons participated in the study. Two videos were prepared of a total of 10 fundus pictures with or without lines for disc foveal angle. The first video had a 4 s viewing time for each fundus image. The second video had the disc foveal lines drawn and a similar 4 s viewing time for each image. The participants were asked to grade the torsion. The primary outcome measure was to assess the agreement between the raters for ocular torsion measurement. Difference in the response of observers from the standard response was the secondary outcome measure. Results: A 4 s viewing time was given to mimic the exposure time in the clinic while assessing torsion in a patient. Large variability was found among the responses. The kappa test was done for comparing the agreement between various observers which ranged from slight to fair (<0.40). There was no difference in torsion grading in 30.6% and 26.3% responses in the first and second video from the standard response, respectively. When a limit of ±1 grade was taken as acceptable for the responses, 66.2% for the first and 68.7% for the second video respectively were similar to standard response. Conclusion: There is wide variability in assessing ocular torsion by fundus photography. The level of accuracy does increase with marking the line on photographs but still remains unreliable.

Effect of bilateral superior oblique split lengthening on torsion.

Introduction: Superior oblique split lengthening (SOSL) is done for weakening of superior oblique. It corrects the superior oblique overaction (SOOA) and A pattern. Its effect on the torsion of the eye is not known. We present our data on the effect of this particular procedure on torsion. Materials and Methods: We did a study of 16 patients (32 eyes) who underwent bilateral SOSL and compared the disc foveal angle (DFA) preoperatively and postoperatively. The split lengthening was done from 4 mm to 7 mm depending upon the overaction of superior oblique. Results: The mean age was 15.3 ± 8.4 years. Mean preoperative DFA in the right eye (RE) was −3.9° and in the left eye (LE) was −2.9°. Mean postoperative DFA in RE was 0.2° and in LE was 0.9°. The mean change in the DFA for RE was 4.1° ± 1.3° and for LE was 3.8° ± 1.2°. All the patients were aligned horizontally within 6 prism diopter and no pattern and no diplopia postoperatively. The A pattern was corrected in all the patient postsurgery. For each mm of surgery, an improvement of 0.8° was seen in the DFA. Conclusion: We report the effect of SOSL on torsion. The SOSL reduces intorsion postsurgery and is, therefore, a valuable procedure in SOOA where both pattern and in torsion needs to be corrected.

Comparison of Diplopia and Ocular Torsion Rate in Blow-Out Fracture Patients

PURPOSE: We compared ocular torsion rates in blow-out fracture patients before and after blowout fracture repair by analyzing mean disc foveal angles. METHODS: The study participants were divided into 2 groups: blow-out fracutre repair patients (n = 36) and controls (n = 36). We measured ocular torsion rates by analyzing mean disc foveal angle. The angle was composed of 2 imaginary horizontal lines which crossed the optic disc center and fovea. We compared statistically ocular torsion rates in blow-out fracture patients based on subsided diplopia, continued diplopia, or absence of diplopia before and after blow-out fracture repair using paired t-test. RESULTS: In the patient group, ocular torsion rates were statistically significantly decreased. In the blow-out fracture repair group with subsided diplopia, ocular torsion rates were decreased statistically from 7.74 +/- 3.48 degrees before blow-out fracture repair to 5.02 +/- 3.11 degrees after blow-out fracture repair. In the blow-out fracture repair group with continued diplopia or absence of diplopia before surgery, ocular torsion rates did not change statistically significantly from 6.36 +/- 2.80 degrees before blow-out fracture repair to 6.51 +/- 3.24 degrees after blow-out fracture repair. CONCLUSIONS: Subsided diplopia after blow-out fracture repair and ocular torsion rate changes were significantly related in blow-out fracture patients. Further research which on the correlation of intraorbital change and movement of orbital position after blow-out fracture repair with ocular torsion rates are necessary.