Innovative techniques for the treatment of adult strabismus

Surgery for longer duration supranuclear ophthalmoplegia secondary to brain stem cavernoma: A case report and literature review

BACKGROUND

Previous reports revealed that patients with acquired paralytic strabismus caused by central nervous system diseases are primarily affected by the etiology and treatment of the condition. Strabismus correction for these acquired paralytic strabismus should be performed as soon as the primary disease has been stabilized for 6 months in order to archive a favorable surgical outcome.

CASE

We followed an infrequent case of longer-lasting supranuclear ophthalmoplegia secondary to brain stem cavernoma.

OBSERVATION

A 25-year-old Chinese Han female developed aberrant head posture and ipsilateral conjugate gaze palsies 8 years after the first brainstem hemorrhage caused by pontine cavernoma. The patient was diagnosed with supranuclear ophthalmic palsy and brain stem cavernoma after surgery. A resection-recession procedure along with a rectus muscle transposition was performed. The patient's abnormal head position disappeared, with a normal primary position.

CONCLUSION

Resection-recession procedures combined with rectus muscle transposition works very well for longer duration large-angle strabismus caused by brain stem cavernoma.

Extraocular Muscle Transplantation Surgery for Primary Treatment of Extra Large-angle Squint

Purpose

Large-angle horizontal ocular deviations will commonly require bilateral surgery to correct the primary ocular deviation. However, considering the need for full correction with one surgical procedure and patients' reluctance to be operated on the good eye, such large horizontal ocular deviations may be managed with true muscle transplantation. The authors present a case series of patients who underwent this procedure and develop a surgical table to guide management.

Methods

Patients with horizontal squints measuring 80 prism diopters (PD) or larger in all age groups who underwent extraocular muscle transplantation surgery between January 2019 and June 2022 in Nigeria were included. Preoperative deviation of the squint, sensory evaluation, surgical dosage, and outcomes were documented. Part of the resected muscle was transplanted to give additional recession in the antagonist muscle. Success was defined as deviation corrected by 60% or more or postoperative ocular alignment within 10 PD or less, six weeks postoperatively.

Results

Fourteen patients with extra-large-angle strabismus were operated. Male/female ratio was 0.6:1. Mean preoperative deviation of 89.6 ± 9.3 collapsed to 6.6 ± 1.8 PD at six weeks and continued to improve to a mean deviation of 2.5 PD at six months postoperatively. When the subgroup of patients who were < 18 years were analyzed, the outcome was equally successful; preoperative deviation of 89.4 PD collapsed to 1.4 PD, six months postoperatively. There were equal success rates when those with sensory strabismus were compared with those with binocular vision; preoperative deviation of 92.5 PD in the sensory group and 88.5 PD in the binocular group collapsed to 5.9 PD and 1 PD, respectively, six months after surgery.

Conclusion

A viable alternative for treating extra-large-angle strabismus in adults and children in developing countries was described with good postoperative outcome. In addition, a new expanded surgical dosage table for muscle transplantation surgery corrections of up to 130 PD was developed.

Effect of Applying Binocular Visual Training after Slanted Lateral Rectus Recession on Orthophoric Rate and Binocular Visual Function Recovery on Patients with Convergence Insufficiency-Type Intermittent Exotropia

OBJECTIVE

To explore the effect of applying binocular visual training after slanted lateral rectus recession on orthophoric rate and binocular visual function recovery on patients with convergence insufficiency-type intermittent exotropia (CI-IXT).

METHODS

A total of 76 CI-IXT child patients treated at the Strabismus and Pediatric Ophthalmology Department of our hospital from June 2019 to June 2020 were selected as the research objects, and those who met the inclusion criteria were equally divided into group A (63 eyes) and group B (61 eyes) according to the sealed envelope randomization. All child patients accepted the slanted lateral rectus recession, and after that, those in group A accepted the binocular visual training and those in group B accepted the conventional visual function rehabilitation training, so as to compare their position of eye, the best corrected visual acuity, etc., after training for statistical analysis.

RESULTS

Compared with group B after one month of surgery, group A had significantly less patients with grade I binocular vision function (P < 0.001) and more patients with grade II and III vision function (P < 0.05); between group A and group B, after 3 months and 6 months of treatment, the number of eyes with normal stereoscopic vision was significantly higher in group A (P < 0.05); at 15 days, 1 month, 3 months, and 6 months of treatment, the visual strain scores of group A were significantly lower (P < 0.001); after treatment, the number of orthophoria eyes was significantly higher in group A (P < 0.001), while the numbers of overcorrected eyes and undercorrected eyes were significantly higher in group B (P < 0.001); and the total incidence rate of adverse reactions was significantly lower in group A (P < 0.05).

CONCLUSION

Applying binocular visual training to child patients with CI-IXT after slanted lateral rectus recession can promote the recovery of binocular vision and ensure higher safety, and further study will help to establish a better solution for the affected children.

Horizontal rectus muscle transplantation for recurrent and residual strabismus

Purpose: To report outcomes of muscle transplantation for recurrent/residual strabismus. Retrospective, multicentric, observational study.  Methods: We retrospectively reviewed records of all patients operated at three institutes who underwent transplantation of the resected muscle for re-operations for residual/recurrent strabismus from January 1, 2018, to December 31, 2019. Data were collected regarding age, gender, visual acuity, type of strabismus, fixation preference, associated amblyopia, the surgical procedure performed, preoperative and postoperative primary position deviation, limitation of ductions, associated intra-operative and post-operative complications. Surgical success was defined as heterotropia less than or equal to 8 PD, and cosmetic success was defined as manifest deviation ≤12 PD (at 6 weeks follow up). Results: During this period, we identified records of seven patients (5 men: 2 women, median age: 24 years) who underwent muscle transplantation for residual/recurrent strabismus. Six patients underwent extraocular muscle surgery for residual/recurrent exotropia (XT) and one for residual esotropia (ET). In all the patients, median pre-operative primary position deviation reduced from 40 prism diopters (PD) (range: 30 to 55 PD) to 8 PD (range: 6 PD ET to 10 PD XT) at six-weeks follow-up. Four patients had residual exotropia (10-16PD), two had orthotropia and one patient had small-angle esotropia (6PD) at the last follow-up. Excluding two patients who underwent supramaximal re-recession of lateral rectus (≥11 mm from insertion) and re-resection of medial rectus, 3/5 (60%) patients achieved surgical success, and all (100%) achieved cosmetic success at six-weeks-follow-up. There was mild (up to -1) limitation of duction in all patients except one patient (-2 limitation of abduction) who underwent re-recession of lateral rectus to 11 mm from insertion along with medial rectus re-resection and muscle transplant procedure. No intra-operative or post-operative complications were encountered. No patient reported postoperative diplopia. Conclusions: This study describes the feasibility and successful use of muscle transplantation procedure to correct residual/recurrent strabismus, with or without re-recession, especially in patients planned for surgery in one eye. However, larger prospective studies with longer follow-ups will be needed to establish long-term outcomes and correction achieved from this procedure, and comparison with other approaches for reoperations.

Muscle Transplantation for Large Angle Horizontal Strabismus

Large angle sensory strabismus in the form of esotropia and exotropia often calls for bilateral surgery to correct the primary angle deviation. However, considering patients' reluctance to have surgery on the good eye, such large deviations may be managed with true muscle transplantation. The authors present a case series of four patients with large angle esotropia and exotropia who underwent unilateral true muscle transplantation as a single-stage procedure. [J Pediatr Ophthalmol Strabismus. 2020;57:e59-e62.].