Purpose: To evaluate the learning curve for exoscope and three-dimensional (3D) 4K hybrid visualization in terms of operating time, advantages, disadvantages, and surgical complications in tubular-access minimally invasive spine surgery (MISS) and to assess surgeon satisfaction with image quality, ergonomics, and ability to perform target site treatment.
Overview of Literature: Working through tubular retractors poses a challenge. The extreme angulations during microsurgical decompression, especially contralateral decompression, require surgeons to work non-ergonomically. An exoscope allows surgeons to work ergonomically and independently of the microscope oculars as visualizations are now provided by large 3D 4K monitors. However, the value and efficacy of solely depending on an exoscope and 3D 4K monitors during microsurgical work are still unknown.
Methods: Seventy-four patients (99 levels) underwent trans-tubular MISS between March 2018 and January 2019. Five patients were excluded: one had pyogenic discitis, two had revisions, and two were trans-tubular transoral. In total, we analyzed 69 for operating time, blood loss, and complications. The learning curve graph was plotted using the surgical time for each procedure. Surgeons were asked to rate their satisfaction with image quality, ability to maintain ergonomic posture, and efficient target site treatment.
Results: For tubular microdiscectomy, the operating time plateaued after six cases, and for tubular decompression and minimally invasive transforaminal lumbar interbody fusion, the operating time plateaued after nine cases. Mean operating time was significantly reduced after the plateau. Complications included four cases of dural tear. All patients improved symptomatically, and there were no postoperative neurological deficits.
Conclusions: Use of the exoscope has a short learning curve. Surgeons benefit from improved ergonomic posture during surgery, and resident teaching appears to be good. The only drawback is the need to rearrange the operating table setup. Complications were comparable to those when using the surgical microscope. An exoscope with hybrid digital visualization provides excellent visualization, depth perception, clarity, and precision target site treatment.
METHODS: Visual screening was conducted in 400 preschool children aged 4 to 6 years. The screening involved two basic procedures; the distant visual acuity test using the Sheridan Gardiner chart and the depth perception test using the Langs stereoacuity test. Criteria for referral were a visual acuity of 6/12 or less in the better eye or a fail in the depth perception test.
RESULTS: The prevalence of visual impairment was 5% (95% confidence interval [CI] = 3.3, 7.6). Of the 400 preschool children screened, 20 of them failed the distant visual acuity test or the stereopsis test. Refractive errors were the most common cause of visual impairment (95%, 95% CI = 76.2, 98.8); myopic astigmatism was the commonest type of refractive error (63.2%, 95% CI = 40.8, 80.9).
CONCLUSION: The study is a small but important step in the effort to understand the problem of visual impairment among our preschool children. Our study showed that it is feasible to measure distant visual acuity and stereopsis in this age group.
DESIGN: Prospective interventional case series.
METHODS: Patients with bilateral significant cataracts and pre-existing corneal astigmatism underwent cataract surgery and implantation with the AcrySof™ IQ Vivity™ toric IOL. Dominant eyes were targeted at emmetropia and non-dominant eyes at -0.50D. Primary endpoints were binocular uncorrected distance (UDVA), intermediate (UIVA at 66 cm) and near (UNVA at 40 cm) acuities at 3 months. Secondary outcomes were corrected distance (CDVA), distance corrected intermediate (DCIVA) and distance corrected near (DCNVA), refractive predictability, rotational stability, binocular defocus curve, contrast sensitivity, Questionnaire for Visual Disturbances (QUVID) and Visual Function Index (VF-14) questionnaire scores. All visual acuities were converted to logarithm of minimum angle of resolution (logMAR) for analysis.
RESULTS: 30 patients underwent uneventful phacoemulsification. The mean binocular UDVA, UIVA and UNVA were 0.06 ± 0.12, 0.11 ± 0.10 and 0.26 ± 0.10 respectively. The mean refractive spherical equivalent (MRSE) for dominant and non-dominant eyes were - 0.07D ± 0.27 and - 0.12D ± 0.54 respectively. 92.4% of dominant eyes and 84.6% of non-dominant eyes within 0.50D of target. The mean IOL rotation was 3.85° ± 5.09 with 86.7% of eyes with less than 5° of rotation. 26.7%, 20% and 36.7% of patients reported starbursts, haloes and glare respectively. The mean VF-14 score was 91.77.
CONCLUSION: Bilateral implantation of the AcrySof™ IQ Vivity™ Toric IOL resulted in very good unaided visual acuities for far and intermediate distance with functional near vision. Dysphotopsias were reported but despite this, a high level of visual function was achieved.