Effect of 4-week preoperative prism adaptation in preventing postoperative residual esotropia.

BACKGROUND: Preoperative prism adaptation (PPA) simulates postoperative status and possibly can predict postoperative undercorrection before surgery in esotropia. The present study aimed to assess the effect of 4-week PPA in preventing postoperative residual esotropia. METHODS: Seventy-five (75) esotropes who had undergone surgery at a single strabismus center were retrospectively enrolled. They included 25 basic, 31 acute comitant, 10 partially accommodative, and 9 recurrent esotropia patients. The preoperative deviation angle, which had been determined using the alternating prism and cover test, was fully corrected with press-on prisms 4 weeks before surgery. If there was an increase of 5 PD or more of esodeviation, the prisms were changed accordingly at 2 weeks. The deviation angle measured at 4 weeks was determined as the surgical target angle. Patients were then divided into increase (≥ 5 PD increase of angle during 4-week PPA) and non-increase groups. Success was defined as either esodeviation of 8 PD or under or exodeviation of 5 PD or under at distance at postoperative 6 months. RESULTS: The increase group included 44 patients (58.7%). The mean deviation angle before PPA was 27.4 PD, and after the 4-week PPA, there was an average increase of 9.4 PD. The success rate was 90.9% in the increase group and 96.8% in the non-increase group (p = 0.316). There were no intergroup differences in preoperative clinical characteristics, esotropia types, postoperative deviation angle or postoperative near stereopsis (p > 0.05). CONCLUSIONS: The results of this study indicated a beneficial effect of 4-week PPA in esotropia of various types, specifically by uncovering the hidden esodeviation in the increase group and simulating the postoperative alignment in both the increase and the non-increase groups.

Long-term surgical outcomes of patients with consecutive exotropia.

PURPOSE: To evaluate the long-term surgical outcome of patients with consecutive exotropia. METHODS: Patients who underwent surgery for the treatment of consecutive exotropia between January 2008 and July 2016 with a minimum follow-up period of 2 years were retrospectively reviewed. Surgical outcomes were classified based on postoperative angle of deviation at 2 years as follows: success (esodeviation ≤ 5 prism diopters [PD] to exodeviation ≤ 10 PD), and recurrence [exodeviation > 10 PD]). Postoperative angles of deviation at 1 week, 1 month, 6 months, 1 year, and 2 years and at the final follow-up were investigated. RESULTS: A total of 37 patients (28 in the success group and 9 in the recurrence group) were included. Surgical success rate at 2 years was 75.7%, and reoperation rate was 10.8% during a mean follow-up period of 42.4 ± 18.3 months after consecutive exotropia surgery. After surgery, exodrift occurred mostly during 1-month follow-up in both groups, and those with no exodrift within 1 month presented a higher surgical success. Thereafter, patients in the success group showed a more stable course during follow-up than those in the recurrence group. Stereopsis was an important factor associated with surgical outcome. CONCLUSIONS: Exodrift occurs mostly within 1 month after surgery for consecutive exotropia. Targeting initial overcorrection and establishing esodeviation at postoperative month 1 is important to achieve successful results.

Phased strabismus surgery under topical anesthesia.

PURPOSE: To evaluate the feasibility and outcomes of phased strabismus surgery under topical anesthesia, with intraoperative comparison of ocular alignment in supine and seated positions. METHODS: This retrospective clinical investigation analyzed the data of patients who underwent phased strabismus surgery with fixed sutures under topical anesthesia. The technique consisted of 2 phases, spaced out with an intraoperative alternate prism cover test (performed in supine and seated positions): (1) surgery on one or two muscles, as defined by a preoperative surgical plan; (2) if judged necessary, a further one-muscle surgery. Surgical success was defined as a residual angle of horizontal and vertical deviation ≤±8Δ and ≤5Δ, respectively, and the presence of single binocular vision in primary position in patients with preoperative diplopia. Follow-up visits were scheduled 1 day, 1 month, and 6 months after surgery. RESULTS: The review identified 38 patients (age range: 10-80 years). Surgery was well tolerated by all patients. Twelve (32%) required a second phase. No statistically significant differences were found for intraoperative angles of deviation in supine and seated positions. Surgical success was reached, respectively, in 88% and 87% of cases with horizontal and vertical deviation 6 months after surgery. No patients were reoperated during the follow-up period. CONCLUSIONS: Phased strabismus surgery is a feasible technique for various types of strabismus in adults and children. Secondly, intraoperative evaluation of ocular alignment can be performed either with the patient seated or supine, with the same accuracy in terms of surgical success.

A Novel Method Ensuring an Immediate Target Angle After Horizontal Strabismus Surgery in Children.

Purpose: Pediatric strabismus surgery has low success rates and high reoperation rates because of difficult alignment measurements and the nature of different strabismus types. Furthermore, adjustable sutures are not easily employed in children on an OPD basis. Methods: This was a retrospective comparative case study of children less than 12 years old who underwent strabismus surgery and were followed up at least 6 months postoperatively. We proposed a novel method that combines adjustable sutures and corneal light reflexes in regular strabismus surgery to improve surgical results. Efficacy and safety were evaluated and compared with those in a regular fixed-suture group. Results: In total, 128 children (88: exotropia and 41: esotropia) in the novel method group (Group 1) and 109 (71: exotropia and 38: esotropia) in the regular fixed-suture group (Group 2) were enrolled. The primary outcome was the immediate target angle (for esotropia within 4 PD of orthotropia and exotropia within 8 PD of esotropia within the first week postoperatively); the secondary outcome was success at the 6-month visit (angle of deviation < 10 PD). Consequently, there was a significantly higher proportion of achieving the immediate target range and success rate in both exotropic and esotropic patients in Group 1 than in Group 2. A significantly lower reoperation rate was also demonstrated in Group 1. No complications were noted in either group.Conclusions: The novel method enabled a higher proportion of subjects to achieve an immediate target range and success rate and a lower chance of reoperation among both esotropic and exotropic patients.

Evaluation on Effectiveness of a New System as well as Analysis on Optimal Horizontal Eye Position for Vertical Video Head Impulse Test.

OBJECTIVE: To compare the performances among three different systems for video head impulse test (vHIT), and to identify an optimal target angle for precisely evaluating the function of vertical semicircular canals in vHIT. METHODS: A two-center prospective study was done. Participants were sit 1.2 m away from the wall in a noise-proved room that dedicated for vHIT experiments. During the comparison experiments, similar settings were ensured in both hospitals, with the same distance to wall and angle of staring. For each equipment, the procedures followed the developers' recommendations. The same examiner performed the comparison between two systems in one location. For the eye-position projects, targets were placed on the wall sequentially at the pre-marked lines for different angles. For the comparison projects, 9 and 13 participants were recruited, respectively. Any participant with otologic or vestibular disorders was excluded. A total of 26 healthy participants were recruited in the eye-position experiments, 16 of which were further involved in inter-examiner tests. RESULTS: Our evaluations of three different systems showed that a new vHIT system, VertiGoggles® ZT-VNG-I (VG) performed as good as the long-tested Otometrics® ICS impulse (Oto) and EyeSeeCam® (ESC). During the comparison, we validated 25-degree, instead of right ahead at 0 degree, is a better place to set the targets when torsion was applied at vertical semicircular canal planes. CONCLUSION: The new VG system is good for clinical practices. Furthermore, we proposed a new protocol to set the targets 25 degrees from right ahead after tilting head 45 degrees to evaluate vertical canals during vHIT.

Surgical outcomes for esotropia in children with high accommodative convergence/accommodation ratio.

PURPOSE: To assess if high accommodative convergence/accommodation (AC/A) ratio impacts surgical outcomes in children with esotropia (ET), and evaluate the appropriate target angle in surgical dosing in the presence of high AC/A ratio. METHODS: A retrospective chart review identified patients who underwent primary bilateral medial rectus (BMR) recessions for ET. Patients were excluded if follow-up was ≤2 months. Basic demographic information, visual acuity, stereopsis, alignment, and target angle for surgery were collected. High AC/A was defined as ≥10 prism diopter (Δ) deviation at near compared to distance. Outcome parameters were near and distance deviations ≤10Δ within orthophoria, and/or stereopsis postoperatively. Yates' continuity correction, unpaired t-test, regression analysis, and one-way ANOVA were used. RESULTS: We identified 103 patients, 23 with high AC/A and 80 with normal AC/A, preoperatively. Mean age was 4.0 ± 2.5 years. Surgical success measured by postoperative alignment was 48% and 45% in the high AC/A and normal AC/A groups, respectively (P = 1.0). There was a statistically significant difference in preoperative near deviation between high AC/A and normal AC/A groups (P = 0.0015); however, there was no significant difference in preoperative distance deviation (P = 0.061). In addition, there was not a significant difference in preoperative or postoperative stereopsis between high AC/A and normal AC/A groups (P = 0.88 and P = 0.44, respectively). There was a significant difference in the normal AC/A and high AC/A groups when target angle was directed toward preoperative near deviation as determined by one-way ANOVA (F = 170.88, P < 0.0001 and F = 14.61, P = 0.0010, respectively). CONCLUSION: In the setting of ET treated with BMR recession, the presence of high AC/A does not affect surgical success as measured by alignment and stereopsis. In addition, when high AC/A is present, surgical dosing with a target angle toward near deviation was found to yield the best surgical outcomes in our patient population.

The effects of kinesio™ taping on proprioception at the ankle.

UNLABELLED: An experiment was designed to determine if Kinesio™ taping the anterior and lateral portion of the ankle would enhance ankle proprioception compared to the untaped ankle. 30 subjects, 15 men, 15 women, ages 18-30 participated in this study. EXCLUSION CRITERIA: Ankle injury < 6 months prior to testing, significant ligament laxity as determined through clinical evaluation by an ATC, or any severe foot abnormality. Experiment utilized a single group, pretest and posttest. Plantar flexion and inversion with 20° of plantar flexion reproduction of joint position sense (RJPS) was determined using an ankle RJPS apparatus. Subjects were barefooted, blindfolded, and equipped with headphones playing white noise to eliminate auditory cues. Subjects had five trials in both plantar flexion and inversion with 20° plantar flexion before and after application of the Kinesio™ tape to the anterior/lateral portion of the ankle. Constant error and absolute error were determined from the difference between the target angle and the trial angle produced by the subject. The treatment group (Kinesio™ taped subjects) showed no change in constant and absolute error for ankle RJPS in plantar flexion and 20° of plantar flexion with inversion when compared to the untaped results using the same motions. The application of Kinesio™ tape does not appear to enhance proprioception (in terms of RJPS) in healthy individuals as determined by our measures of RJPS at the ankle in the motions of plantar flexion and 20° of plantar flexion with inversion. Key PointsProprioception researchEvaluation of a new taping methodAugmentation of sensory feedbackRehabilitation technique.