Perioperative visual loss: what do we know, what can we do?

Cranio-Orbital Approach and Decompression of the Optic Nerves: A 2-Stage, 4-by-4-Step Approach to Improve Vision in Sellar and Parasellar Lesions

BACKGROUND AND OBJECTIVES

Despite advances in cranial base techniques, surgery of the sellar and parasellar regions remains challenging because of complex neurovascular relationships. Lesions within this region frequently present with progressive visual deterioration caused by distortion and compression of the optic chiasm and nerves. In addition to the direct mass effect from mechanical forces acting on the optic apparatus, these lesions alter blood supply and reduce vascular perfusion, prompting surgical treatment to remove the lesion, alleviate compression, and improve blood flow to the optic nerve. We sought to describe a 2-stage, 4-by-4-step approach, broken down and described as a "four-by-four" technique for optic apparatus decompression and a wide approach to different sellar and parasellar lesions.

METHODS

We describe the operative nuances and key anatomic points in the microsurgical removal of sellar and parasellar lesions. The technique is illustrated with examples of different cases with pre- and follow-up MRI imaging and a brief overview of visual outcomes.

RESULTS

The described technique has been demonstrated in various lesions in 5 patients. Patients presented with bilateral visual loss in 4 (80.0%) cases and with unilateral visual loss in 1 (20.0%) case. Improvement in visual function was noted in all cases, confirmed with visual acuity and visual field testing.

DISCUSSION

The transcranial approach ("from above") remains an important surgical option for patients with excellent exposure and visualization of the sellar and parasellar regions. It permits early access to the optic canal for careful microsurgical decompression and relaxation of the optic nerve to preserve and improve its microvascularization and ultimately vision.

CONCLUSION

The authors augmented the 2-stage, 4-by-4-step technique of decompression with elaborate illustrations of diverse sellar and parasellar lesions to demonstrate the versatility of this approach.

Post-operative Unilateral Visual Loss and Ophthalmoplegia following Cervical Spine Surgery in Prone Position: A Case Report

ABSTRACT

Visual loss following a spine surgery in a prone position is a disastrous and irreversible complication. Moreover, the recommended treatment for such visual loss is lacking and the outcome is not so satisfactory. A 38-year-old gentleman developed profound right sided visual loss after an uneventful cervical spine surgery in a prone position that lasted approximately two and half hours. Immediate ophthalmic consultation was done and the case was diagnosed as right-sided central retinal artery occlusion. Despite the initiation of vasodilatation, anticoagulation, and adequate fluid infusion, satisfactory improvement was not achieved. Extensive review of pertinent literature highlighted limited efficacy of treatments for postoperative visual loss after prone spinal surgery, further emphasizing the importance of preventive measures as the cornerstone in such procedures.

Incidence and Risk Factors for Postoperative Visual Loss after Cardiac Surgical Procedures: A Systematic Review

ABSTRACT

Postoperative visual loss (POVL) is an infrequent yet consequential complication that can follow cardiac surgical interventions. This systematic review aims to provide a comprehensive analysis of the incidence of POVL after cardiac surgery and to delineate the associated risk factors. A comprehensive search was conducted in major medical databases for relevant studies published up to September 2022. Eligible studies reporting on the incidence of POVL and identifying risk factors in patients undergoing cardiac surgery were included. Data extraction was performed independently by two reviewers. The pooled incidence rates and the identified risk factors were synthesized qualitatively. POVL after cardiac surgery has an overall incidence of 0.015%, that is, 15 cases per 100,000 cardiac surgical procedures. Risk factors for POVL include patient characteristics (advanced age, diabetes, hypertension, and preexisting ocular conditions), procedural factors (prolonged surgery duration, cardiopulmonary bypass time, and aortic cross-clamping), anesthetic considerations (hypotension, blood pressure fluctuations, and specific techniques), and postoperative complications (stroke, hypotension, and systemic hypoperfusion). Ischemic optic neuropathy (ION) is an uncommon complication, associated with factors like prolonged cardiopulmonary bypass, low hematocrit levels, excessive body weight gain, specific medications, hypothermia, anemia, raised intraocular pressure, and micro-embolization. Diabetic patients with severe postoperative anemia are at increased risk for anterior ischemic optic neuropathy (AION). Posterior ischemic optic neuropathy (PION) can occur with factors like hypertension, postoperative edema, prolonged mechanical ventilation, micro-embolization, inflammation, hemodilution, and hypothermia.While the overall incidence of POVL postcardiac surgery remains modest, its potential impact is substantial, necessitating meticulous consideration of modifiable risk factors. Notably, prolonged surgical duration, intraoperative hypotension, anemia, and reduced hematocrit levels remain salient contributors. Vigilance is indispensable to promptly detect this infrequent yet visually debilitating phenomenon in the context of postcardiac surgical care.

Central retinal artery occlusion after spinal surgery: Case report and literature review

AIM

To report a rare case of unilateral central retinal artery occlusion (CRAO) following spinal surgery.

METHODS

Observational case report.

RESULTS

A 15-year-old female patient underwent scoliosis surgery under general anesthesia in a prone position, her head being supported by a horseshoe headrest for approximately four hours, with stable vitals and without significant blood loss during surgery. Upon waking up from general anesthesia, the patient immediately reported severe visual loss in her right eye (RE), associated to marked periocular ecchymosis and chemosis. Visual acuity was limited to light perception. Fundus examination showed normal optic disc appearance with diffuse retinal pallor and a macular cherry red spot. Optical coherence tomography (OCT) showed increased reflectivity in the inner retina, consistent with ischemic maculopathy in the RE. Brain and neck magnetic resonance imaging angiograms were unremarkable. Further investigations ruled out collagen vascular disease, Behcet disease, syphilis, sickle cell disease and hypercoagulable states.

CONCLUSION

Central retinal artery occlusion is rarely observed following spinal surgery. The cause was presumed to be compression of the orbit by a horseshoe headrest in a prone position due to an accidental shift in position during surgery. This catastrophic complication, albeit rare, is usually irreversible and thus must be prevented. Proper positioning and vigilance by both the surgeon and the anesthesiologist during surgery are fundamental to ensure that the orbits are not under pressure.

Orbital infarction during drug abuse: tissues of the globe do not appear to recover function

AIM

To describe the features of an orbital infarction syndrome arising after prolonged orbital pressure during drug-induced stupor in young people.

PATIENTS AND METHODS

The clinical presentation and course for drug-induced orbital infarction is described, based on a retrospective review of clinical notes and imaging.

RESULTS

Two cases of orbital infarction syndrome, due to prolonged orbital compression caused by sleeping with pressure on the orbit during drug-induced stupor, are described. Both patients presented with very poor vision and mydriasis, marked periorbital swelling with some pain, and complete external ophthalmoplegia. Whilst the orbital changes and eye movements recovered, the affected eyes had persistent wide mydriasis, and remained blind with marked optic atrophy.

CONCLUSION

With a mechanism analogous to prolonged orbital pressure due to improper head positioning during neurosurgical procedures, drug-users appear to risk developing an orbital infarction syndrome if they rest with prolonged pressure on the orbit during a drug-induced stupor.

The Effect of Visual Impairment on Postural Stability After Lumbar Spine Fracture: A Case Report and Review of the Literature

The role of vision in maintaining postural stability is crucial, and its loss, whether congenital or acquired, can significantly impact sensory-motor interactions, leading to musculoskeletal abnormalities and defective gait patterns. This case report discusses the complex interplay between visual impairment, post-traumatic kyphosis, and the development of spinal deformity in a 79-year-old blind patient. The patient sustained a simple fall resulting in an L1 compression fracture in 2016. Despite conservative treatment for the fracture, progressive spinal deformity became evident both clinically and radiographically. Further assessments, including evaluation of bone healing, facet arthroplasty, disc degeneration, and canal compromise, were performed. The patient's altered gait and postural abnormalities were indicative of the impact of visual impairment on postural stability. After addressing osteoporosis through endocrinology consultation and medical management, the patient underwent posterior spinal instrumentation and deformity correction, leading to a successful post-operative recovery with a return to baseline functional status. Visual impairment disrupts postural stability by limiting sensory input and prompting compensatory mechanisms, which may increase postural sway and instability. This abnormal gait further contributes to spinal deformities, and the fear of falling can exacerbate postural instability, limiting mobility. Over time, persistent postural imbalance leads to the creation of a state of continual asymmetric stress related to the spinal axis, which can progress to the development of spinal deformities, creating a self-perpetuating cycle.  This case underscores the significance of vision in postural stability and the adverse effects of visual impairment on spinal alignment. The development of spinal deformities in visually impaired individuals, especially in the presence of risk factors like osteoporosis, emphasizes the need for early intervention and postural training to prevent irreversible deformities. Decisions regarding surgical or non-surgical interventions for spinal deformities in visually impaired patients must consider multiple factors, including clinical symptoms, appearance, pain, functional limitations, and social issues. Future research should explore effective interventions for improving postural stability in visually impaired individuals and preventing the development of spinal deformity.

Perioperative visual loss and consent for adult spine surgery: a national survey of the practice amongst spine surgeons and anaesthetists†

BACKGROUND

Perioperative Visual Loss (POVL) is a devastating complication for patients undergoing spine surgery. Consent process for POVL amongst spine surgeons and anaesthetist remains variable. The aim of this study is to evaluate their practice and views about it.

METHODS

Two similar questionnaires were distributed to members of the Society of British Neurological Surgeons (SBNS), British Association of Spine Surgeons (BASS), and Neuroanaesthsia and Critical Care Society (NACCS).

RESULTS

A total of 271 responses were received (SBNS/BASS n = 149, NACCS n = 122). Fewer surgeons considered POVL as a material risk for patients compared to the anaesthetists (57.7 versus 79.7%). Outpatient/pre-assessment clinics were considered as the optimal setting for discussing POVL by the majority of the clinicians (81.2 and 93.4%). POVL should be discussed by both specialists according to 75% of the anaesthetists. Estimated incidence of POVL was considered to be higher by the anaesthetists (0.03-0.2% by 63% of the anaesthetist versus 0.0001-0.004% by 57% of the surgeons). Twenty-three surgeons and 10 anaesthetists had a patient who suffered from POVL, which led to a change of practice in most of them. This questionnaire will lead to a change in practice/consent to 18.1% of the surgeons and 23.5% of the anaesthetists.

CONCLUSIONS

Most of the surgeons and anaesthetist feel that POVL is a material risk that ideally needs to be firstly discussed before the day of surgery, by both specialties. However, a significant number of clinicians have an opposite view. A national guidance from respective societies should encourage POVL to be discussed routinely.

Study on the relationship between scoliosis and vision problems: A narrative review

Adolescent scoliosis is one of the most common surgical disorders of the pediatric spine. With timely detection and early treatment, most scoliotic children can avoid major and expensive surgery. Vision problems are also frequently found at an early age and can take a toll on individuals quality of life. However, scoliosis, a severe health hazard to adolescents, is often accompanied by vision problems clinically, including myopia, astigmatism, strabismus, amblyopia, horizontal paralysis, and blindness. And people with genetic defects have a higher probability of suffering both spinal problems and vision problems than those with nongenetic defects. However, many individuals viewed scoliosis and vision problems as 2 irrelevant diseases. This review searched PubMed, China National Knowledge Infrastructure, and Web of Science for studies on adolescent, scoliosis, eye diseases, myopia, strabismus, spinal disorders, and vision problems for almost 3 decades, and thus confirmed the potential relationship between adolescent scoliosis and vision problems.

The effect of restrictive vs. liberal fluid protocols on ocular parameters in patients undergoing prone spine surgery: a randomized controlled trial

BACKGROUND

Elevated intraocular pressure (IOP) and optic nerve edema occurring during prone surgeries may cause ocular and optic nerve ischaemia injury. We hypothesized that a liberal fluid protocol might further increase IOP and optic nerve sheath diameter (ONSD) than a restrictive fluid protocol for patients in the prone position.

METHODS

A single-centre, prospective and randomized trial was conducted. Patients were randomly allocated into 2 groups: the liberal fluid infusion group, in which repeated bolus doses of Ringer's lactate solution were given to maintain pulse pressure variation (PPV) within 6~9%, and the restrictive fluid infusion group, where PPV was maintained within 13-16%. IOP and ONSD were measured in both eyes at 10min after the anaesthesia induction in the supine position, 10min after the prone position placement, and 1h and 2h since the prone position was placed, at the conclusion of surgery, and returned to the supine position.

RESULTS

A total of 97 patients were recruited and completed the study. IOP increased significantly from 12±3mmHg in the supine position to 31±5 mmHg (p<0.001) at the end of surgery in the liberal fluid infusion group and from 12±2 to 28±4 mmHg (p<0.001) in the restrictive fluid infusion group. There was a statistically significant difference in the change of IOP over time between the two groups (p=0.019). ONSD increased significantly from 5.3±0.3mm in the supine position to 5.5±0.3mm (p<0.001) at the end of surgery in both groups (both p<0.001). There was no statistically significant difference in the change of ONSD over time between the two groups (p>0.05).

CONCLUSIONS

Compared to the restrictive fluid protocol, the liberal fluid protocol increased IOP but not ONSD in patients undergoing prone spine surgery.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov ( https://clinicaltrials.gov ) prior to patient enrollment, ID: NCT03890510, on March 26, 2019. The principal investigator was Xiao-Yu Yang.

Complications of Lateral Decubitus Positioning During Orthopaedic Surgery

» Lateral decubitus positioning is a nonanatomical position used for multiple orthopaedic procedures to obtain adequate surgical exposure.» Unique ophthalmologic, musculoskeletal, neurovascular, and hemodynamic complications may arise inadvertently from positioning.» Orthopaedic surgeons should be aware of the possible complications that may manifest from placing patients in the lateral decubitus position to adequately prevent and to properly manage them.

Unilateral Optic Nerve Diffusion Restriction After Sinus Surgery Secondary to Central Retinal Artery Occlusion: Case Report and Literature Review

INTRODUCTION

Permanent perioperative vision loss is caused by ischemic optic neuropathy (ION) or central retinal artery occlusion (CRAO). Whereas diffusion restriction of the optic nerve (ON) on brain magnetic resonance imaging has been previously reported in perioperative posterior ION (PION), there are no reports of ON diffusion restriction in patients diagnosed with acute perioperative CRAO. We present a case of perioperative CRAO to highlight this neuroimaging finding for neuroradiologists and neurologists.

CASE REPORT

A 71-year-old male without vascular risk factors underwent maxillary bilateral antrostomy and septoplasty for chronic sinusitis. Twenty to thirty minutes upon awakening, he complained of painless left eye vision loss. Ophthalmoscopic examination showed retinal whitening, segmented arterioles, and hyperemic disc. Brain MR-diffusion weighted imaging/apparent diffusion coefficient revealed ON diffusion restriction in the proximal segment. Despite attempted reperfusion, left eye remained with no light perception at 6 months. Patients undergoing nonocular surgeries who develop perioperative vision loss related to PION may exhibit ON diffusion restriction but usually have normal ophthalmoscopic findings. CRAO shows retinal whitening, edema, segmentation of arterioles, and cherry red spot on ophthalmoscopy. A recent study reported that ON diffusion restriction in nonperioperative CRAO cases has a sensitivity and specificity of 55% and 70% to 100%. Here, PION was initially considered based on imaging. However, given the neuro-ophthalmic findings, a proximal embolus in the central retinal artery, obstructing its entrance into the proximal ON was deemed more likely.

CONCLUSION

We highlight that proximal ON diffusion restriction on brain magnetic resonance imaging can be diagnostic of proximal thromboembolic CRAO. Future studies should evaluate the diagnostic utility and accuracy of MR-diffusion weighted imaging/apparent diffusion coefficient in perioperative visual loss.

Body Balance Analysis in the Visually Impaired Individuals Aged 18-24 Years

BACKGROUND

Proper body balance is maintained by both sensory, i.e., vision, hearing, vestibular, and proprioception, and motor nervous systems. Visual control facilitates balance both in a static position, as well as during movement. Visual dysfunctions can adversely affect balance and stability control.

METHODS

The study comprised a group of 30 individuals visually impaired from birth aged 18-24 years. The control group consisted of 50 persons in the same age range as the study group. The trial was performed as four separate tests: two on a stable surface platform, and two on an unstable surface platform.

RESULTS

No statistically significant differences were found in the posturography test on the stable platform between the study groups. When tested on an unstable ground surface, the visually impaired subjects obtained showed worse performance than the sighted persons. Statistically significant differences were observed in the majority of the analyzed results.

CONCLUSIONS

Visually impaired individuals present a poorer ability to maintain balance under dynamic conditions. Tests conducted on the unstable surface platform seem to be more relevant and applicable in the diagnosis of the subjects with visual impairment, as they differentiate the subjects to a greater extent.

Posterior ischemic optic neuropathy following postoperative bleeding and internal jugular vein compression

Perioperative blindness, especially posterior ischemic optic neuropathy (PION), is an uncommon but potentially devastating complication. We report a case of a 65-year-old male patient who underwent laryngopharyngectomy, bilateral neck dissection, and free jejunum flap reconstruction, but then experienced PION in his right eye following postoperative bleeding and bilateral internal jugular veins (IJVs) compression. Despite systemic corticosteroid therapy, his visual recovery prognosis was poor. The specific mechanism responsible for PION remains unclear, and no therapy has been shown to improve this condition. As such, prevention of perioperative PION remains the only available strategy. Surgeons should be aware of this rare potential complication and its risk factors and strive to avoid it. As postoperative bleeding and IJV compression are one of important risk factors for PION, avoiding these are critical.

Perioperative considerations for cancer patients with obesity: A narrative review

Cancer in patients with obesity has become increasingly common throughout much of the world. Based on our experiences in a specialized cancer center, we have developed a set of standards and expectations that should streamline the surgical journey for this patient population. These recommendations should inform the perioperative management of oncology patients with obesity and help raise awareness of this critical and under-discussed topic.

Eye Care Interventions in Critical/Surgical Patients in the Prone Position: Scoping Review

Objectives: This study aimed to map evidence of eye care interventions in managing critical or surgical patients submitted to prone positions. Materials and method: This scoping review was prepared according to the Joanna Briggs Institute’s methodology, following the PRISMA-ScR criteria. A search was conducted from July to August 2020 in the SCOPUS, Web of Science, Science Direct, PubMed Central, CINAHL, and COCHRANE databases. The following research question was delimited: “What are the strategies and interventions used for eye care in the management of critical patients or surgical patients submitted to the prone position?” The sample consisted of 24 studies after applying the inclusion and exclusion criteria. Results: Eye care interventions in managing critical/surgical patients submitted to the prone position were eye examination, use of lubricants/specific ophthalmic solution, reverse Trendelenburg positioning, and protection with adhesive tape. Conclusions: This review allowed the understanding of eye care for critical/surgical patients in a prone position. Among the care presented, a large part is related to nursing since it is closer to patient care. The findings emphasize the need to implement patient safety policies with eye care as a priority.

Factors Affecting Optic Nerve Damage in Le Fort III Osteotomy: A Retrospective Study

The causes of visual impairment following Le Fort osteotomy for syndromic craniosynostosis have not been completely elucidated. The authors investigated the potential causes and means of prevention of optic nerve damage, with particular emphasis on intraoperative blood transfusion volume and operating time. This retrospective study evaluated patients who underwent Le Fort III osteotomy for syndromic craniosynostosis between 2000 and 2020. Data on pupillary reflex, pupil size, operating time, blood transfusion, age at time of surgery, sex, and syndrome type were obtained from medical records. Univariate analysis and multivariate analysis with the level of statistical significance set at P<0.05. For the 86 patients included, the mean values of operating time, amount of blood transfusion based on body weight, amount of blood transfusion per body weight per hour, and age were 6.0 hours (range: 3.5-12.3 h), 30.5 mL/kg (range: 0-322 mL/kg), 5.14 mL/kg/h (range: 0-35.7 mL/kg/h), and 10.0 years (range: 4-38 y), respectively. Crouzon, Apert, and Pfeiffer syndromes were observed in 49, 29, and 8 patients, respectively. Abnormal pupillary findings were observed in 27 patients of whom 25 showed no abnormalities in subsequent visual function and 2 developed blindness. Abnormal pupillary findings correlated with the amount of blood transfused per body weight (P=0.0082) and amount of blood transfused per body weight per hour (P=0.0052). As demonstrated in this study, increased intraoperative bleeding and amount of blood transfused were associated with optic nerve damage, particularly during acute bleeding. Prompt inspection of the pupils following surgery is therefore warranted.

Cognitive-Motor Interference during Dual Tasks in Blind Children

The aim of the present study was to compare the dual-task (DT) performance in blind children with sighted ones while concurrently performing a motor task (upright standing) with cognitive (Letter fluency (LF) or Category fluency (CF)) tasks. The Center of pressure mean velocity (CoP_Vm) and the cognitive performances were recorded during single (ST) and DT conditions. Results showed that, for both groups, CoP_Vm values increased significantly (p < 0.05) in the DT compared to ST condition. The CoP_Vm values were significantly (p < 0.001) higher in blind children, compared to controls only in the DT-CF condition. In conclusion, balance performance of blind and typically developed children is affected by dual tasking. Interference between motor and cognitive tasks has more pronounced effects on balance performance in blind children, compared to controls. This difference was observed only when performing the CF task concurrently with the postural balance task.

Robot-assisted kidney transplantation: an update

Renal transplantation has become the gold-standard treatment for the majority of patients with established renal failure. Recent decades have seen significant progress in immunosuppressive therapies and advances in post-transplant management of recipients, resulting in improved graft and patient outcomes. However, the open technique of allograft implantation has stood the test of time, remaining largely unchanged. In a world where major advances in surgery have been facilitated by innovations in the fields of biotechnology and medical instrumentation, minimally invasive options have been introduced for the recipient undergoing kidney transplantation. In this review we present the evolution of minimally invasive kidney transplantation, with a specific focus on robot-assisted kidney transplant and the benefits it offers to specific patient groups. We also discuss the ethical concerns that must be addressed by transplant teams considering developing or referring to robotic programs.

Posterior Ischemic Optic Neuropathy after Cervical Spine Surgery

Purpose: To describe a patient with posterior ischemic optic neuropathy (PION) after cervical spine surgery who recovered after treatment.Case summary: A 51-year-old woman presented with eye pain and decreased visual acuity in the left eye, which had begun 8 hours after cervical spine surgery in the prone position. Her best-corrected visual acuity (BCVA) was 20/20 in the right eye and hand motion in the left eye; a relative afferent pupillary defect was present in the left eye. Ductions and versions were normal with pain in the left eye. The results of slit lamp examination, fundoscopic examination, fluorescein angiography, and optical coherence tomography were unremarkable in both eyes. Brain and orbital magnetic resonance imaging showed no abnormal findings in the visual pathway, such as brain infarction or intracranial artery stenosis. The patient was diagnosed with PION in the left eye. Because postoperative anemia had developed with a rapid decrease in hemoglobin from 14.7 g/dL to 9.9 g/dL, red blood cell (RBC) transfusion was performed together with intravenous high-dose steroid therapy and subcutaneous epoetin alfa injection. After 3 weeks, the patient’s BCVA improved to 20/22 in the left eye.Conclusions: Unilateral PION developed after cervical spine surgery in the prone position. Visual improvement was observed after RBC transfusion, intravenous high-steroid therapy, and subcutaneous epoetin alfa injection.

Incidence and risk factors of postoperative visual function impairment in elderly patients undergoing nonocular surgery: a prospective cohort study

BACKGROUND

Elderly patients may present with visual function impairment after surgery, which may increase the incidence of postoperative delirium and falls and decrease their quality of life. The aim of this study was to assess visual function in elderly patients after long-duration nonocular surgery to determine the incidence and risk factors for visual function impairment after surgery.

METHODS

This prospective and observational study included patients aged between 60 and 80 years who had been scheduled for elective nonocular surgery expected to last longer than 120 minutes under general anesthesia. Ocular examinations were performed before surgery, on postoperative day 3 and on postoperative day 21 and consisted of a LogMAR-Snellen chart test, a Jager chart test, biomicroscopy, optical tonometry, ocular motility assessment and fundoscopy. Baseline characteristics of all patients as well as intraoperative and postoperative data were collected.

RESULTS

A total of 107 patients were included in the final analysis. Visual function impairment was diagnosed in 21 patients (19.6%) at POD 3. Of those, 7 patients (6.5%) still presented with visual changes at POD 21. On POD 3, compared with that at baseline, visual acuity assessed by the Snellen chart test had decreased in these patients. Significant differences regarding refraction tests and intraocular pressure measures were also found. Multivariable analysis identified diabetes mellitus, duration of surgery, hypotension during anesthesia induction, lower peripheral oxygen saturation at the end of the procedure and body mass index as independent risk factors for postoperative visual impairment.

CONCLUSION

In elderly patients undergoing long-duration nonocular procedures under general anesthesia, the incidence of visual function impairment was considerably high. Most patients recovered to baseline visual function, but clinically significant visual changes may still be present 3 weeks after surgery. Obesity, diabetes mellitus, and the duration of surgical and anesthetic techniques appear to increase the risk of visual impairment after surgery.

Posterior ischemic optic neuropathy following a major burn injury and review of the literature

Posterior ischemic optic neuropathy following burns is a rare but devastating condition that can result in total bilateral visual loss. Numerous treatment modalities have been trialed, yet there is no effective therapy to delay or reverse the disease. Hence, it is imperative for burns surgeons to be aware of the potential risk factors and have a high index of suspicion right from the outset to prevent this outcome. Here, we discuss the case of a patient that developed posterior ischemic optic neuropathy subsequent to a major burn injury. We also present a literature review on optic neuropathies following burns to describe the etiology, clinical signs, and potential management.

Checking the integrity of eyes in prone position: A novel application of video laryngoscopes

Perioperative visual loss is a rare but severe complication after surgery in prone position. One of several mechanisms is direct ophthalmic compression. This can be avoided through optimal positioning and padding of the head, but position and integrity of the eyes need to be checked at regular intervals. We describe the use of a conventional video laryngoscope during vascular surgery in prone position as a simple solution for intermittent monitoring of external integrity of the eyes and size of the pupils. This requires no additional material and allows documentation of the findings. Our method might reduce complications and improve patient outcome.

No significant retinal damage induced by major orthopedic surgery - a pilot study

BACKGROUND

Perioperative visual loss is one of the rare but devastating complications of anesthesia and surgery. The incidence of less severe or even subclinical postoperative visual dysfunction is unknown. Therefore, we decided to perform a pilot prospective observational clinical study to evaluate whether structural changes of the retina can be detected in patients undergoing elective orthopaedic surgery by optical coherence tomography (OCT).

METHODS

Adult patients indicated for elective knee replacement surgery with the absence of known retinal or optic nerve disease were included. Each patient underwent baseline OCT examination of the eyes one day before surgery and it was repeated 4-7 days after the surgery. The surgery was done under general and epidural anesthesia.

RESULTS

A total of 18 patients (6 men and 12 women) at the age of 70.8±7.1 years were enrolled. We found statistically significant changes in the Macular central thickness and in a few areas of the Retinal Nerve Fiber Layer between the baseline and postoperative measurements.

CONCLUSIONS

Even though we found significant changes in some parameters, we did not confirm that general anesthesia and/or surgical damage causes significant damage of the retina using OCT measurement.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04311801).

Complete Vision Loss after Laparoscopic Hysterectomy

Postoperative vision loss (POVL) is a rare but devastating complication that has only recently been reported following laparoscopic surgery. We present the case of a 34-year-old gravida 6 para 4 female who experienced POVL following an uncomplicated laparoscopic hysterectomy. Operating time was 174 minutes, and EBL was 75 mL. After surgery, she complained of complete vision loss with no light perception. No cerebral hemorrhage or ischemia was detected on imaging. Funduscopic exam revealed no structural abnormalities. On postoperative day 7, she received an IV methylprednisolone taper. The following morning, she reported mild light perception. Later that night, she reported a partial return of visual acuity and was discharged home. At her 2-week postoperative visit, her vision had returned to baseline. POVL is an emergency and prompt evaluation should be initiated to optimize outcome.

Ocular complications of perioperative anesthesia: a review

Ocular complications associated with anesthesia in ocular and non-ocular surgeries are rare adverse events which may present with clinical presentations vacillating between easily treatable corneal abrasions to more serious complication such as irreversible bilateral vision loss. In this review, we outline the different techniques of anesthetic delivery in ocular surgeries and highlight the incidence and etiologies of associated injuries. The changes in vision in non-ocular surgeries are mistaken for residual sedation or anesthetics, therefore require high clinical suspicion on part of the treating ophthalmologists, to ensure early diagnosis, adequate and swift management especially in surgeries such as cardiac, spine, head and neck, and some orthopedic procedures, that have a comparatively higher incidence of ocular complications. In this article, we review the literature for reports on the clinical incidence of different ocular complications associated with anesthesia in non-ocular surgeries and outline the current understanding of pathophysiological processes associated with these adverse events.

Sudden painless loss of vision following spine surgery: lessons learnt in darkness

A 26-year-old male driver presented with a history of pain in the neck for the past 1 week following trauma due to a road traffic accident. The patient had no neurological deficit. He had type 1 diabetes and was on regular oral hypoglycemics. After radiological investigations, the patient was diagnosed to have traumatic AO Spine Classification type C translational injury involving anterolisthesis of C6 over C7. After a detailed preoperative assessment, the patient was taken up for surgery. The patient underwent posterior stabilisation with instrumentation from C5 to T2. On extubation from anaesthesia, he immediately complained of complete painless loss of this vision in his left eye. Ophthalmological investigations attributed the cause to be due to central retinal artery occlusion. The patient was discharged with reassurance on the 20th postoperative day with minimal improvement in his vision and at 6-month follow-up, his vision improved to 1/60 and was advised for close follow-up.

Plan de cuidados de enfermería para la prevención de úlceras por presión secundarias a la posición prono en pacientes COVID-19

Introducción: La posición prono (PP) es una alternativa terapéutica ampliamente recomendada e implementada en los pacientes con COVID-19. Sin embargo, aunque es un procedimiento no invasivo, es complejo y se asocia con eventos adversos como las úlceras por presión (UPP). Nuestro objetivo es proponer un plan de cuidados de enfermería basado en el lenguaje estandarizado NANDA-I, NIC, NOC para la prevención de las UPP secundarias a la PP en la enfermedad de COVID-19. Síntesis del contenido: En los pacientes con COVID-19, además de factores de riesgo propios del paciente como la edad avanzada y la presencia de comorbilidades, la PP contribuye a la presencia de los diagnósticos de enfermería de riesgo de úlcera por presión [00249], de deterioro de la integridad cutánea [00047] y tisular [00248]. Por su parte, la intervención de enfermería prevención de úlceras por presión [3540], es clave para minimizar el desarrollo de esta complicación, mejorar la calidad de la atención y el pronóstico en este tipo de pacientes. Finalmente, para determinar la efectividad del cuidado de enfermería se proponen los resultados NOC consecuencias de la inmovilidad: fisiológicas [0204] e integridad tisular: piel y membranas mucosas [1101]. Conclusión: La PP es una terapia coadyuvante recomendada para el manejo de los pacientes con COVID-19 críticamente enfermos, debido a que optimiza la función pulmonar, sin embargo está asociada a eventos adversos como las UPP. Este artículo presenta recomendaciones basadas en una revisión narrativa para facilitar la implementación de cuidados de enfermería preventivos que reduzcan su frecuencia en esta población.

Quantitative rise in intraocular pressure in patients undergoing robotic surgery in steep Trendelenburg position: A prospective observational study

BACKGROUND AND AIMS

Raised intraocular pressure (IOP) is one of the known causes of anterior ischemic optic neuropathy. In the case of robotic urological-gynecological surgeries, patient is kept in steep Trendelenburg supine-lithotomy position. Aim of this study was to observe the quantitative rise in IOP in steep Trendelenburg position (>45°) in robotic-assisted prostatectomy and hysterectomy.

MATERIAL AND METHODS

After institutional ethical clearance and written informed consent, 100 patients undergoing robotic surgeries in steep Trendelenburg position were recruited for the study. IOP was measured at different time intervals in steep Trendelenburg position using Schiotz tonometer: Post intubation (T1), post pneumoperitoneum (T2), post steep Trendelenburg (T3), and rest readings were taken 30 min apart. T9 was taken 10 min after patient is made supine and parallel to the ground. Mean arterial pressure (MAP), positive inspiratory pressure (PIP), and end-tidal carbon dioxide (EtCO2) values were recorded at different time points. Descriptive analysis, linear regression analysis, and Freidman's nonparametric tests were used to analyze the results.

RESULTS

Ninety-five patients were included for statistical analysis as five patients were excluded due to intraoperative interventions leading to alteration of results. Mean IOP at T1 was 19.181/18.462 mmHg in L/R eye. A gradual rise in IOP was observed with every time point while patient was in steep Trendelenburg position which reverts back to near normal values once the patient is changed to normal position 21.419/20.671: Left/right eye in mm of Hg. Uni and multiple regression analysis showed insignificant P value, thus no correlation between MAP, PIP, and EtCO2 with IOP.

CONCLUSION

Steep Trendelenburg position for prolong duration leads to significant rise in intraocular pressure.

Orbital Compartment Syndrome Following Major Burn Resuscitation: A Case Series and Survey of Practice Patterns

Orbital compartment syndrome (OCS) is a rare but devastating complication of over-resuscitation in burn patients that may lead to permanent visual loss. The purpose of this study was to 1) present a series of burn patients with OCS and 2) survey practice patterns of monitoring intra-ocular pressure (IOP) during burn resuscitation. Cases of OCS at two American Burn Association (ABA)-verified burn centers were retrospectively reviewed. Patients were included if they 1) required lateral canthotomy/cantholysis for elevated IOPs or 2) developed blindness on admission unrelated to any other ocular pathology. Data were collected on demographics, burn characteristics, fluid administration, ophthalmologic findings, and complications. An eight-item electronic survey was distributed by email through the ABA to all physician members. Twelve patients with OCS were identified, with a mean age of 47.8 ± 12.4 years and TBSA of 63.7 ± 18.6%. Mean fluid resuscitation at 24 hours was 4.9 ± 1.6 ml/kg/%TBSA or 0.29 ± 0.06 liter/kg. Eight patients underwent canthotomy/cantholysis for OCS, whereas four were later found to have visual loss. A total of 83 (14%) ABA physicians responded to the survey. IOP was routinely measured by 23% of respondents during acute burn resuscitation. OCS appears to have developed despite a relatively low 24-hour ml/kg/% burn resuscitation volume, but with a relatively higher cumulative (liter/kg) fluid volume. Their survey found that monitoring of IOP during burn resuscitation is not routinely performed by the majority of providers. Taken together, the present study suggests clinical guidelines to recognize this complication of over-resuscitation.

Intraoperative Fluid Management in Patients Undergoing Spine Surgery: A Narrative Review

Fluid management has been widely recognized as an important component of the perioperative care in patients undergoing major procedures including spine surgeries. Patient- and surgery-related factors such as age, length of the surgery, massive intraoperative blood loss, and prone positioning, may impact the intraoperative administration of fluids. In addition, the type of fluid administered may also affect post-operative outcomes. Published literature describing intraoperative fluid management in patients undergoing major spine surgeries is limited and remains controversial. Therefore, we reviewed current literature on intraoperative fluid management and its association with post-operative complications in spine surgery.

[Ischemic optic neuropathies]

Ischemic optic neuropathies include any vascular disease of the optic nerve. Anterior ischemic optic neuropathies are classically distinguished from posterior ischemic optic neuropathies by the presence of optic disc edema in the former, and the absence thereof in the latter. Non-arteritic acute anterior ischemic optic neuropathy is the most common ischemic optic nerve disease. Its exact cause remains unknown. A disc at risk (small and crowded optic nerve) is a typical backdrop for the development of non-arteritic ischemic optic neuropathy. There is no curative or preventive treatment. Posterior ischemic optic neuropathy is exceedingly rare, compared to anterior ischemic optic neuropathy. It is more frequent in patients with cardiovascular risk factors or in the perioperative period. There is no treatment. In any case of ischemic optic neuropathy, an arteritic cause must be ruled out urgently through clinical and paraclinical examinations. The most frequent cause is giant-cell arteritis. In this case, emergency treatment with intravenous methylprednisolone is required in order to limit vision loss in the affected eye and to prevent vision loss in the other eye.

Postural stability in people with visual impairment

BACKGROUND

The visual system enables the brain to assess information regarding the position of the body in space. Congenital or acquired blindness leads to the development of abnormal sensory-motor interactions that results in development of typical musculoskeletal deformities and gait patterns that cause disability. Diabetes and related complications are expected to increase exponentially in the next 10 years; thus, the number of people with visual impairment is expected to increase. However, there have been few studies regarding etio-pathogenesis of postural alteration and balance impairment in people with visual impairment; moreover, no previous study has investigated postural stability in this population. This study aimed to assess the center of gravity (COG) velocity in subjects with visual impairment and compared with that in sighted subjects.

METHODS

Seventy male subjects, 20-40 years of age, participated in this study; they were divided into sighted (control) and visually impaired groups. COG velocity while standing on an unstable surface was measured using the NeuroCom^® Balance Master Version 8.5.0. For the sighted group, data were recorded with eyes open and then with eyes closed. For the visually impaired group, no instructions were given with respect to eyes during data collection.

RESULTS

Mean COG velocity was significantly higher in the visually impaired group than in the sighted group with eyes open. However, there was no difference in mean COG velocity between the visually impaired group and the sighted group with eyes closed. The difference in mean COG velocity between sighted subjects with eyes open and eyes closed was also significant. Mean COG velocity while standing on a foam surface varied among visually impaired subjects and sighted subjects with eyes open and closed.

CONCLUSION

This study showed that subjects with visual impairment, regardless of eye opening or closure, behave in the same manner as sighted subjects with eyes closed.

Unilateral Vision Loss without Ophthalmoplegia as a Rare Complication of Spinal Surgery

Postoperative visual loss is an extremely rare complication of nonocular surgery. The most common causes are ischemic optic neuropathy, central retinal artery occlusion, and cerebral ischemia. Acute visual loss after spinal surgery is even rarer. The most important risk factors are long-lasting operations, massive bleedings, fluid overload, hypotension, hypothermia, coagulation disorders, direct trauma, embolism, long-term external ocular pressure, and anemia. Here, we present a case of a 54-year-old male who developed acute visual loss in his left eye after a lumbar instrumentation surgery and was diagnosed with retinal artery occlusion.

Tarik Syndrome: Reversible Postoperative Blindness Secondary to Occipital Seizures

BACKGROUND

Postoperative blindness is a devastating surgical complication. Although usually associated with prolonged cardiac and prone spinal operations, it may follow other procedures as well. Postoperative blindness is most commonly caused by a vascular etiology, but it can more rarely be caused by status epilepticus. We have previously reported a case of this phenomenon following a staged spinal deformity surgery.

CASE DESCRIPTION

Here we report 2 additional cases following a skull base procedure and a single stage lumbar spine surgery. In all instances, rapid recognition that the patients' blindness was due to occipital seizures resulted in acute antiepileptiform treatment and full restoration of vision.

CONCLUSIONS

Although a rare phenomenon, this syndrome, first recognized and described by Tarik F. Ibrahim, should be considered in any patient with postoperative visual impairment.

Postoperative Visual Loss: A Report of One Patient With Unilateral Blindness After Orthognathic Surgery

INTRODUCTION

Blindness after orthognathic surgery may be the result of the surgical procedure itself or the consequence of factors induced by general anesthesia. However, the exact mechanism between is not known. The purpose of this article is to present a case of a postoperative visual loss after orthognathic surgery under general anesthesia concluding with a brief literature review about this topic.

REPORT OF CASE

We report the case of a patient who suffered unilateral blindness with homolateral frontal paresthesia after orthognathic procedure in 2 steps. He presented intraoperative bradycardia with a potential undiagnosed hypertension, associated with significant blood loss and volume resuscitation by colloids and cristalloids.Postoperative examination concluded to posterior ischemic optic neuropathy.

DISCUSSION AND CONCLUSION

By a systematic literature review, we discuss about surgical and anesthesic causes of postoperative visual loss, and particularly pathophysiology mechanism of posterior ischemic optic neuropathy. Some predisposition and risk factors have been identified and need to be taken into account.

An Observational Study of Cerebral Blood Flow Velocity Evaluation in the Prone Position During Posterior Lumbar Surgery

BACKGROUND

Prone positioning (PP) is necessary for surgical access during posterior spine procedure. However, physiological changes occur in the PP. Typical findings are a decrease in arterial blood pressure and in cardiac output that could potentially lead to an alteration in cerebral perfusion. Therefore, we decided to study cerebral blood flow velocity (CBFV) with transcranial Doppler ultrasonography to evaluate the effect of the PP on cerebral hemodynamics.

METHODS

Twenty-two patients undergoing spine surgery in the PP were studied. General anesthesia was induced using 250 μg of fentanyl, 2 mg/kg of propofol, and 0.1 mg/kg of vecuronium, and was maintained with 0.25%-0.5% isoflurane, 50% nitrous oxide in oxygen, continuous infusion of 100 μg/kg/min of propofol, 1.5 μg/kg/h of fentanyl, and 0.15 mg/kg/h of ketamine. Continuous invasive arterial blood pressure, heart rate, electrocardiogram, and end-tidal carbon dioxide were monitored. CBFV with transcranial Doppler in the middle cerebral artery was first measured with the patients under general anesthesia in the supine position. Patients were then placed in the PP and remained in this position throughout surgery. CBFV, end-tidal carbon dioxide, heart rate, and blood pressure were measured continuously for 75 minutes after initiation of PP. This coincided with surgical exposure and minimal blood loss. Data were analyzed every 15 minutes for statistical significant change over time.

RESULTS

Mean arterial blood pressure decreased 15 minutes after the installation of the PP and onward, but this decrease was not statistically significant. CBFVsyst (the maximal CBFV during the systolic phase of a cardiac cycle) and CBFVmean (the time averaged value of the maximal velocity envelope over 1 cardiac cycle) did not vary at any time points. CBFVdiast (the CBFV just before the acceleration phase [systole] of the next waveform) was lower at T3 (30 minutes after PP) compared to T1 (value derived averaging the first measure in the PP with the ones at 5 and 10 minutes) (P = .01), and the pulsatility index was higher at T5 (60 minutes after PP) compared to T0 (baseline, patient supine under general anesthesia) (P = .04). Data were analyzed at specific time points (T0 and T1). This value was derived by computing an average of the CBFV values collected at the first measure in the PP and at 5 and 10 minutes thereafter: T2, 15 minutes after PP; T3, 30 minutes after PP; T4, 45 minutes after PP; T5, 60 minutes after PP; and T6, 75 minutes after PP.

CONCLUSIONS

Our data on CBFV during PP for spine surgery demonstrate preservation of cerebral perfusion during stable systemic hemodynamic conditions. The present results do not allow us to determine whether the PP would be similarly tolerated with increasing length of surgery, variations in systemic hemodynamics, and in different patient populations.

Visual Loss Following Spine Surgery: What Have We Seen Within the Scoliosis Research Society Morbidity and Mortality Database?

STUDY DESIGN

A retrospective review of the Scoliosis Research Society (SRS) morbidity and mortality (M&M) database.

OBJECTIVE

The aim of this study was to investigate visual related complications in spinal deformity patients undergoing spine surgery.

SUMMARY OF BACKGROUND DATA

The SRS compiles surgeon-reported complications into an M&M database, tracking postoperative complications including visual loss, neurological deficits, infections, and death. Limited literature exists on postoperative visual complications, a rare but devastating complication following spine surgery.

METHODS

We utilized the SRS M&M database to determine demographics, perioperative risk factors, and prognosis for visual related complications in spinal deformity patients undergoing corrective spine surgery from 2009 to 2012.

RESULTS

A total of 167,972 spinal deformity patients from 2009 to 2012 were identified with a visual acuity complication (VAC) rate of 0.01%, or 12.5 per 100,000 patients. VAC rates for patients with kyphosis were significantly higher than patients with scoliosis (0.049% vs. 0.010%, P = 0.002) and spondylolisthesis (0.049% vs. 0.005%, P = 0.001). Postoperative visual loss rates significantly decreased from 2010 to 2012 (0.022% vs. 0.004%, P = 0.029). Twenty-one patients identified with VACs had a mean age of 34.8 ± 24.3 years. Two (9.5%) patients had preoperative vision changes, two (9.5%) were diabetic, two (9.5%) had vascular disease, one (4.8%) had a history of thromboembolic disease, and five (23.8%) had hypertension. Extent of VAC was bilateral-partial in four (19.0%), bilateral-total in five (23.8%), unilateral-partial in eight (38.1%), and unilateral-total in three (14.3%) patients. Four (19.0%) patients developed anterior ischemic optic neuropathy, four (19.0%) had posterior ischemic optic neuropathy (PION), five (23.8%) had central retinal artery occlusion, and five (23.8%) developed cortical blindness (CB). Greater than 50% of the VACs occurred on, or before, the first postoperative day. Ten (47.6%) patients recovered complete vision and four (19.0%) improved. All patients with CB and 50% with posterior ischemic optic neuropathy experienced complete resolution.

CONCLUSION

VACs occur in approximately 12.5 per 100,000 deformity patients, with a rate five times higher in patients with kyphosis. More than 50% of these complications occur within 24 hours postoperatively. Nearly half of these complications resolve completely, and another 19% improve postoperatively.

LEVEL OF EVIDENCE

4.

Complications of Supine Surgical Achilles Tendon Repair

BACKGROUND

Open Achilles tendon surgery with the patient in the supine position potentially avoids the complications of the prone position, but the safety and viability of the supine position for this procedure are not known. The aim of this study was to test the hypothesis that supine positioning for open repair of acute Achilles tendon ruptures would be safe, with low wound and neurologic complication rates.

METHODS

Supine position safety in acute Achilles tendon repair was investigated. Consecutive cases of supine Achilles tendon surgical repair performed by one surgeon from 2010 to 2015 were retrospectively reviewed. Patients were included if they were surgically treated with primary repair in the supine position within 15 days of injury and did not undergo concomitant surgery. A paramedian incision 1 cm medial to the Achilles sheath was used. Initial chart review identified 161 patients who underwent any type of Achilles tendon surgery in the supine position, of whom 45 patients met the inclusion criteria. This group included 39 men and 6 women with an average age of 41 years (range, 20-66 years). Median length of follow-up was 116 days (range, 25-1,589 days). Average body mass index was 29 kg/m² (range, 23-36 kg/m²).

RESULTS

There were no infections, sural nerve injuries, or reruptures.

CONCLUSIONS

The supine position was safe for primary open Achilles tendon repair, with no wound or neurologic complications.

LEVEL OF EVIDENCE

Level IV, case series.

Perioperative Retinal Artery Occlusion: Incidence and Risk Factors in Spinal Fusion Surgery From the US National Inpatient Sample 1998-2013

BACKGROUND

Retinal artery occlusion (RAO) is a rare but devastating complication of spinal fusion surgery. We aimed to determine its incidence and associated risk factors.

METHODS

Hospitalizations involving spinal fusion surgery were identified by searching the National Inpatient Sample, a database of hospital discharges, from 1998 to 2013. RAO cases were identified using ICD-9-CM codes. Using the STROBE guidelines, postulated risk factors were chosen based on literature review and identified using ICD-9-CM codes. Multivariate logistic models with RAO as outcome, and risk factors, race, age, admission, and surgery type evaluated associations.

RESULTS

Of an estimated 4,784,275 spine fusions in the United States from 1998 to 2013, there were 363 (CI: 291-460) instances of RAO (0.76/10,000 spine fusions, CI: 0.61-0.96). Incidence ranged from 0.35/10,000 (CI: 0.11-1.73) in 2001-2002 to 1.29 (CI: 0.85-2.08) in 2012-2013, with no significant trend over time (P = 0.39). Most strongly associated with RAO were stroke, unidentified type (odds ratio, OR: 14.33, CI: 4.54-45.28, P < 0.001), diabetic retinopathy (DR) (OR: 7.00, CI: 1.18-41.66, P = 0.032), carotid stenosis (OR: 4.94, CI: 1.22-19.94, P = 0.025), aging (OR for age 71-80 years vs 41-50 years referent: 4.07, CI: 1.69-10.84, P = 0.002), and hyperlipidemia (OR: 2.96, CI: 1.85-4.73, P < 0.001). There was an association between RAO and transforaminal lumbar interbody fusion (OR: 2.95, CI: 1.29-6.75, P = 0.010). RAO was more likely to occur with spinal surgery performed urgently or emergently compared with being done electively (OR: 0.40, CI: 0.23-0.68, P < 0.001).

CONCLUSIONS

Patient-specific associations with RAO in spinal fusion include aging, carotid stenosis, DR, hyperlipidemia, stroke, and specific types of surgery. DR may serve as an observable biomarker of heightened risk of RAO in patients undergoing spine fusion.