Outcomes of hyperbaric oxygen treatment for central and branch retinal artery occlusion at a major Australian referral hospital.

Introduction: This study analysed the treatment outcomes of patients that received hyperbaric oxygen treatment (HBOT) for retinal artery occlusion (RAO) at the Royal Brisbane and Women's Hospital in Brisbane, Australia between 2015 and 2021. Methods: Retrospective study from patient records including 22 eyes from 22 patients that received HBOT for either central RAO (17 patients) or branch RAO (five patients). Patients received the Royal Brisbane and Women's Hospital RAO protocol for their HBOT. Analysis included best corrected visual acuity pre- and post-treatment, subjective improvements, side effects and patient risk factors were also recorded. Results: Improvement in best corrected visual acuity was LogMAR -0.2 for central RAO on average with 8/17 (47%) experiencing objective improvement, 5/17 (29%) experienced no change and 4/22 (24%) experienced a reduction in best corrected visual acuity. Subjective improvement (colour perception or visual fields) was reported in an additional 4/17 patients, resulting in 12/17 (71%) reporting improvement either in visual acuity or subjectively. There was no improvement in the best corrected visual acuity of any of the five patients suffering from branch RAO. Cardiovascular risk factors present in the cohort included hypertension, hypercholesterolaemia, previous cardiovascular events, cardiac disease and smoking. Limited side effects were experienced by this patient cohort with no recorded irreversible side effects. Conclusions: Hyperbaric oxygen treatment appears a safe, beneficial treatment for central RAO. No benefit was demonstrated in branch RAO although numbers were small. Increased awareness of HBOT for RAO resulting in streamlined referrals and transfers and greater uptake of this intervention may further improve patient outcomes.

Efficacy and safety of a standardized hyperbaric oxygen therapy protocol for retinal artery occlusion.

Introduction: We aimed to assess the efficacy and safety of a standardized hyperbaric oxygen (HBO2) therapy protocol in patients with retinal artery occlusion (RAO). Methods: A retrospective study was conducted in our tertiary care center from July 2016 to September 2019. Patients experiencing central RAO and branch RAO for less than seven days were included. Once the diagnosis was made, patients were urgently referred to the HBO2 department to receive a first 90-minute HBO2 session at a pressure of 2.5 ATA. Patients underwent two daily sessions seven days a week for at least 15 days. If no reperfusion was seen on fluorescein angiography on Day 15, treatment was continued for an additional week with an assessment on Day 21. The primary endpoint was BCVA improvement defined as a decrease by 0.3 logMAR at one month. Results: Twenty-eight patients were included during the study period. Fifty-seven percent of patients were treated more than 12 hours after the onset of the first symptoms. The mean BCVA was 1.5 logMAR at the time of referral and improved to 0.9 logMAR after HBO2 (p=0.001). A multivariate analysis identified a high blood pressure (p=0.039) and a low initial BCVA (p=0.005) as poor prognostic factors. Conclusion: Performing HBO2 sessions twice daily at a pressure of 2.5 ATA appears to be an effective and safe treatment for RAO.

The Effects of Hyperbaric Oxygen Therapy in Patients with Central Retinal Artery Occlusion: A Retrospective Study, Systematic Review, and Meta-analysis.

PURPOSE: Central retinal artery occlusion (CRAO) is a vision-threatening condition with a potentially poor visual prognosis. Many different treatment modalities are suggested but controversy remains regarding effectiveness of these treatments. The purpose of this study is to perform a systematic review and meta-analysis in addition to analyzing retrospective data at our own tertiary care center regarding effectiveness of hyperbaric oxygen therapy (HBOT) in treatment of CRAO. METHODS: The PubMed, Scopus, and the Cochrane Library are searched from the date of database inception to September 2021 to conduct a review based on the PRISMA (preferred reporting items for systematic review and meta-analysis), evaluating the role of HBOT in visual recovery of CRAO patients. In addition, a retrospective chart review of patients clinically diagnosed with CRAO at our university-based hospital (University of Texas Health, San Antonio, TX, USA) from year 2011 to 2021 was conducted. RESULTS: After a review of 376 articles, three articles met the inclusion criteria for meta-analysis, where a total of 207 patients received HBOT versus 89 patients that did not receive any form of oxygen therapy. Analysis of these results demonstrate that HBOT in CRAO patients does not enhance the final visual outcome (p = 0.83). Similar conclusion was also drawn from retrospective analysis of 48 patients (15 HBOT versus 33 controls) at our tertiary care center, where no visual benefit was observed in the HBOT group. CONCLUSIONS: HBOT does not appear to improve final visual outcome and concerns remain regarding adverse reactions such as barotrauma and generalized seizures. Large, randomized studies are required for further understanding of the role of HBOT in treatment of CRAO.

Hyperbaric oxygen treatment for non-arteritic central retinal artery occlusion retrospective comparative analysis from two tertiary medical centres.

OBJECTIVES: To compare the visual outcome of patients treated for non-arthritic central retinal artery occlusion (CRAO) in a medical centre that uses hyperbaric oxygen therapy (HBOT) as part of the standard of care (SOC) to medical centres that does not. METHODS: The study included data from two tertiary medical centres. The medical records of all patients diagnosed with non-arthritic CRAO without a patent cilioretinal artery between January 2010 and December 2018 in two tertiary medical centres were reviewed. RESULTS: One hundred and twenty-one patients were treated by HBOT and 23 patients received only SOC. In the HBOT group, best-corrected visual acuity (BCVA) improved from 2.89 ± 0.98 logMAR at presentation to 2.15 ± 1.07 logMAR upon the end of HBOT (P < 0.001), while the SOC group had no significant improvement, from 3.04 ± 0.82 logMAR at presentation to 2.80 ± 1.50 logMAR (P = 0.24). With adjustment for age, gender, and the duration of symptoms, final BCVA in the HBOT group was significantly better compared to the control group (P = 0.023). Rates of patients achieving vision of 20/200 or better were similar between groups (17.4% vs. 19.8%, P = 0.523). CONCLUSION: Utilizing HBOT as part of the SOC for CRAO improves the final visual outcome. HBOT is safe and can be implemented, if available, as part of SOC in all tertiary medical centres.

Treatment outcomes on neovascularization after CRAO treated with hyperbaric oxygen.

Central retinal artery occlusion (CRAO) is a condition that causes sudden vision loss due to obstruction of the retinal artery, typically from a thrombotic or embolic source. It is often associated with atherosclerotic risk factors, including cardiovascular disease, diabetes, hyperlipidemia, and a history of cerebrovascular disease. CRAO often leads to a poor visual outcome as well as neovascularization of the iris, retina, and optic disc, which can exacerbate vision loss and cause pain. While there are several treatment modalities for CRAO, few have been proven to be effective in decreasing the effects of neovascularization. The use of hyperbaric oxygen (HBO2) therapy is often used in the treatment of CRAO due to its ease of use and relatively benign side effect profile. This study aims to assess the degree of improvement in visual acuity (VA) and neovascularization following HBO2. Our data ultimately shows that 20% of patients developed neovascularization after HBO2 compared to 29.8% of those who did not undergo HBO2 (p<.05). Our findings suggest that HBO2 has a statistically significant protective effect against neovascularization and may improve long-term visual acuity.

CASE SERIES OF HYPERBARIC OXYGEN THERAPY FOR CENTRAL RETINAL ARTERY OCCLUSION.

PURPOSE: To retrospectively report the outcomes of patients presenting to our facility with central retinal artery occlusion and receiving therapy with hyperbaric oxygen (HBO). METHODS: This was a retrospective, chart review at a single hospital center. Patients with diagnosed central retinal artery occlusion were treated with HBO twice daily for 5 days during their inpatient stay for a total of 10 HBO treatments. Main outcome was change from the documented presenting best-corrected visual acuity to discharge best-corrected visual acuity. Thirty-nine patients with central retinal artery occlusion were included in the analysis during a 30-month period. RESULTS: Twenty-eight of 39 patients (72%) had some improvement in acuity. There was a mean of 5.05 lines of improvement using a modified Snellen chart after completing their HBO treatment course. Patients treated within 12 hours of symptom onset showed the greatest improvement in their visual acuity (6.11 mean lines of improvement). Complications of therapy included middle ear barotrauma (10/39) and confinement anxiety (1/39) and did not interfere with the therapy regimen or hospital course. CONCLUSION: This retrospective case series supports the use of emergent HBO therapy as a viable treatment option for patients with central retinal artery occlusion. Hyperbaric oxygen therapy was safely administered and well tolerated.

Hyperbaric oxygen treatment of central retinal vein occlusion with cilioretinal artery occlusion secondary to hormonal treatment: Case report and review.

INTRODUCTION: This report describes a case of central retinal vein occlusion (CRVO) and cilioretinal artery occlusion (CLRAO) after hormonal treatment for induction of ovulation that was successfully treated with hyperbaric oxygen. CASE REPORT: A 48 year-old woman was admitted to our department for sudden blurred vision in her left eye. The patient had a history of 3-months hormonal treatment for induction of ovulation. The best corrected visual acuity was 7/10 (20/32) in the left eye and 10/10 (20/20) in the right eye. Fundus examination of the left eye revealed flame-shaped haemorrhages, whitening of the retina along the distribution of cilioretinal artery and tortuous retinal veins. Fluorescein angiography confirmed the combination of a non-ischaemic CRVO with CLRAO. The patient was treated with a 2 h session of hyperbaric oxygen at 253 kPa (2.5 atmospheres absolute) once daily for a total of 30 sessions. Best corrected visual acuity improved to 10/10 (20/20) in the left eye. CONCLUSIONS: CRVO and CLRAO are both occlusive disorders. HBOT is a safe low-cost treatment modality that can be beneficial in some ocular pathologies. It can maintain oxygenation of the retina through the choroidal blood supply, decrease oedema and preserve compromised tissue adjacent to the ischaemic area.

The Use of Vitamins and Coenzyme Q10 for the Treatment of Vascular Occlusion Diseases Affecting the Retina.

Nutritional supplementation with antioxidants and vitamins is widely recommended in the treatment of vascular disorders affecting the retina, although there is insufficient evidence on its effectiveness. The vitamin-like compound coenzyme Q10 (CoQ10) is a nutritional supplement of current interest to treat neurodegenerative diseases. Here, we report a retrospective clinical case series study of 48 patients diagnosed with retinal vascular diseases, including non-arteritic ischemic optic neuropathy (NAION), retinal artery occlusion (RAO), and homonymous hemianopia or quadrantanopia following stroke, treated with oral supplementation with CoQ10 (100 mg per day) and vitamins. Patient follow-up was performed using the Humphrey field analyzer and 30-2 testing algorithm to determine the visual field index (VFI) and progression rates. All treated patients showed positive VFI progression rates per year: +11.5 ± 15% for NAION patients (n = 18), +22 ± 17% for RAO patients (n = 7), +9.3 ± 10.5% for hemianopia/quadrantanopia patients (n = 10), and +11 ± 21% for patients with other conditions (n = 13). The interruption of CoQ10 supplementation in one patient resulted in a pronounced decrease of the VFI, which was partially recovered when treatment was restored. This study supports the role of CoQ10 as a nutritional therapeutic agent for vascular diseases affecting the retina. Owing to decreased VFI after interruption of CoQ10, its beneficial effects may be reversible.

Acute phase treatment in central retinal artery occlusion: thrombolysis, hyperbaric oxygen therapy or both?

Central retinal artery occlusion (CRAO) is a neuro-ophthalmological emergency. There is a finite time window for acute interventions such as revascularization (e.g. intravenous thrombolysis-IVT) and retinal oxygenation (e.g. hyperbaric oxygen therapy-HBOT) therapies. Case 1: A 35-year-old female presented with CRAO in the right eye (OD) confirmed by fluorescein angiography (FA) and optical coherence tomography (OCT). She underwent 4 sessions of HBOT (100% O2 at 2.4 atmosphere absolute for 90 min). Afterwards, visual defect on the nasal field was kept but visual acuity (VA) improved from counting fingers to 1.0. Case 2: A 65-year-old male presented with CRAO in his left eye (OS) with 1.5 h of evolution. Orbital sonography and OCT confirmed the presence of an embolus and he underwent IVT with rTPA (0.9 mg/kg). VA improved from light perception to 0.1. Case 3: A 21-year-old male presented acute visual loss in his OD with 2.5 h of evolution. OCT and retinography identified CRAO. He was submitted to IVT (rTPA-0.9 mg/kg) followed by 12 sessions of HBOT. VA improved from hand motion to 1.0. Our case series depicts the approaches and possible outcomes in acute management of an infrequent, but highly morbid, cerebroretinovascular disorder. Future clinical trials are warranted to tackle current difficulties in CRAO treatment.

The effect of adjunctive hyperbaric oxygen therapy in patients with central retinal artery occlusion.

Purpose: Central retinal artery occlusion (CRAO) is an ophthalmic emergency with poor prognosis, despite diligent conventional treatment. According to the clinical recommendations of the Undersea and Hyperbaric Medical Society, hyperbaric oxygen (HBO2) is a potentially beneficial treatment; however, the benefit of adjunctive HBO2 in patients with CRAO in Korea remains unclear. The present study aimed to evaluate the effect of adjunctive HBO2 in patients with CRAO. Methods: This registry-based observational study included adult patients who presented to the emergency department or ophthalmology outpatient department within 24 hours of the onset of CRAO symptoms. Data of patients from October 2016 to February 2019 were analyzed. The patients were categorized into two groups according to the use of adjunctive HBO2: no HBO2 and HBO2. Result: During the study period, 34 consecutive patients were enrolled, of which 19 were included in the study. In the total cohort, 10 patients (52.6%) were treated with adjunctive HBO2. There were no statistically significant differences in terms of age, sex, comorbidities, duration from symptoms onset to hospital visit, presence of the cilioretinal artery, and use of anterior chamber paracentesis between the two groups. The HBO2 group showed significantly higher change in best-corrected visual acuity than the no HBO2 group (p=0.043). Conclusion: Patients with CRAO in the HBO2 group showed significantly greater visual improvement than those in the no-HBO2 group. Clinicians should consider adjunctive HBO2 in the treatment approach in patients with CRAO who visit the hospital within 24 hours of symptoms onset.

Hyperbaric oxygen treatment results in a group of Turkish central retinal artery occlusion patients with a combined presence of thrombophilic mutations.

Background: Central retinal artery occlusion (CRAO) is a rare ocular-ischemic syndrome causing irreversible blindness. Its pathophysiology has not been clarified, and no targeted therapies are available yet. Hyperbaric oxygen (HBO2) therapy is already an approved therapy for CRAO and has been shown to improve the visual acuity of CRAO patients safely. However, further clinical data are required to classify HBO2 therapy as a type-I general agreement for CRAO. Materials and Methods: Eleven patients with non-arteritic CRAO were enrolled. Patient demographics, medical history, detailed eye examinations, HBO2 therapy results, pre-/post HBO2 therapy visual acuity measurements and genotypes for common thrombophilic mutations (Factor V G1691A Leiden, Factor II G20210A, MTHFR A1298C, MTHFR C677T, and PAI-1-675 4G/5G) were obtained. Result: Six patients (54%) responded to HBO2 therapy compared to five non-responders (46%). Patients admitted before 12 hours responded well to HBO2 therapy. No systemic diseases nor advanced age were statistically correlated to CRAO. A combination of mutations rather than single mutations for each patient could be seen as responsible for CRAO. No Factor V G1691A Leiden mutations and only one FII G20210A mutation were observed. Eight patients (72%) had MTHFR 677T allele, five patients (45%) had MTHFR 1298C allele, and 10 patients (91%) had the PAI-1-675 4G allele. Conclusion: Not a single mutation but a combination of mutations and other unknown factors probably lead to CRAO, and if intervention is timely, HBO2 therapy offers improvement in visual acuity safely.

Branch retinal artery occlusion in a patient undergoing Methotrexate therapy for ectopic pregnancy: A case report.

Methotrexate is a commonly used agent in the treatment of an un-ruptured ectopic pregnancy. Thromboembolic events are rarely seen side effects of such a medicine. We report the case of the 22-year-old woman who underwent Methotrexate therapy for an un-ruptured ectopic pregnancy without any history of thromboembolic risk factors. A second dose (50 mg/m2) was administered to the patient showing a nondecreasing pattern of ß-HCG levels after an initial standard dosage of Methotrexate (50 mg/m2). On the 12th day of the treatment, a sudden onset of painless vision loss was seen in the right eye. Fundal imaging and fluorescein angiography revealed an occlusion of the superior temporal branch of the right retinal artery. After a month of hyperbaric oxygen therapy, complete recovery without loss of vision was achieved.

Development of visual acuity under hyperbaric oxygen treatment (HBO) in non arteritic retinal branch artery occlusion.

PURPOSE: Nonperfusion of retinal tissue due to arterial occlusion leads inevitably to mostly irreversible retinal damage. Until today no evidence-based treatment exists. Inhalation of 100% oxygen at high atmospheric pressure causes an increased solubility of oxygen in the blood that helps the retinal tissue to survive through diffusion in case of an artery occlusion till vascular recanalization occurs. Hence the purpose of this study is to compare the visual outcome in patients with retinal branch artery obstruction treated with hyperbaric oxygen versus patients treated with hemodilution only. METHODS: Non-randomized, monocentric, retrospective study. Patients with diagnosis of non-arteritic retinal branch artery occlusion (BRAO) treated with hyperbaric oxygen therapy between 1997 and 2017. Exclusion criteria were central retinal artery occlusion, presence of a cilioretinal artery and arteritic cases. The control group was matched based on visual acuity (VA) at admission, age, and delay between symptoms and beginning of clinical care. RESULTS: The control group and the matching oxygen group contained 14 patients each. Initial VA in the matched HBO group was 0.18 ± 0.19 and 0.23 ± 0.19 in the control group (p = 0.57). Final VA at discharge was 0.69 ± 0.29 in the matched oxygen group and 0.32 ± 0.23 in the control group (p = 0.0009). HBO-treated patients had a significant visual increase compared with the control group. The most common comorbidities were arterial hypertension and vascular sclerosis. CONCLUSION: HBO treatment appears to have a beneficial effect on visual outcome in patients with retinal branch artery occlusion. HBO treatment could be a rescue therapy at an early stage of BRAO, especially to bridge the time of a potential reperfusion. However, further, prospective, randomized clinical trials are required to verify this assumption.

Transient Retinal Artery Occlusion After Uncomplicated Rhinoplasty.

PURPOSE: Loss of vision is an extremely rare and unexpected complication following a routine uncomplicated nasal surgery. In majority of patients, visual loss has attributed to retinal emboli which occur with retrograde flow of the intra-arterially injected agents into the nasal cavity or direct trauma to the optic nerve. In this report, the authors present a patient with unilateral decreased vision due to branch retinal artery occlusion soon after a routine nasal surgery. METHODS: Clinical report. RESULT: A 32-year-old female patient admitted to the author' clinic with the complaints of decreased visual acuity in the left eye. She stated that she had undergone rhinoplasty operation 1 week ago and vision loss started immediately after the surgery.In the ophthalmological examination, the best corrected visual acuity with Snellen chart was 1.0 in the right eye and 0.3 in the left eye. In the fundoscopic examination of left eye there was a pale area in the inferior part of the macula. Fundus fluorescein angiography showed no evidence of nonperfusion in the right and left eyes and vascular structure was normal. On the optic coherence tomography, hyperreflectivity and increased thickness were observed in the inner retinal layers of the left eye. In the visual field test, there was a loss of the visual field which corresponds to the pale area on the left eye. Hyperbaric oxygen therapy was recommended. The ophthalmologic examination carried out 2 months later revealed a best corrected visual acuity of the left eye 0.9. In the fundoscopy pale area was regressed in the left eye. Fundus fluorescein angiography showed a good perfusion. There was a little progression in the visual field test. CONCLUSION: Direct mechanical trauma and vasoplastic/embolic vascular events are thought to be possible mechanisms. The authors think in this case, there was a retrograde flow of agents used during the surgery through ophthalmic artery to retinal arteries and vasospasm by epinephrin worsened the situation. Although rare retinal artery occlusion may develop after rhinoplasty, vision loss as a result of a surgery, if done for aesthetic purposes is not acceptable.

Central retinal artery occlusion-A new, provisional treatment approach.

The retinal ganglion cells infarcted in central retinal artery occlusion (CRAO) are the somata of the optic nerve axons, part of the central nervous system. Consequently, CRAO with inner retinal infarction is a small vessel stroke, usually with the devastating consequence of severe visual loss in the affected eye. At present, there is no generally accepted, evidence-based therapy of nonarteritic CRAO in contrast to ischemic cerebral stroke that has well-accepted treatment protocols. Widely divergent and controversial therapeutic options for CRAO reflect the desperation of treating physicians and disparate conflicting studies. We examine reasons why treatment of nonarteritic CRAO remains problematic and then suggest a provisional new approach to treatment based on updated understanding of CRAO pathophysiology and analysis of current therapeutic options and their rationales.

Effect of hyperbaric oxygen treatment in central retinal artery occlusion.

BACKGROUND: Central retinal artery occlusion (CRAO) is a rare and serious ophthalmologic emergency with a bad prognosis. Hyperbaric oxygen (HBO2) treatment has been reported to improve visual acuity of CRAO patients. However, there are unknown variables for HBO2 treatment such as initiation period, number of sessions and efficacy. In this study, we aimed to investigate efficacy of HBO2 treatment in CRAO patients. METHODS: Patients who had been diagnosed with CRAO and referred to our Hyperbaric Oxygen Treatment Unit with the indication of HBO2 treatment were included in the study. Patient demographics, their systemic diseases, best-corrected visual acuity (BCVA) and the time of visual loss were recorded. Oral acetazolamide and topical beta blocker treatments as well as HBO2 treatments were administered to patients as soon as possible. Patients received 20 treatments as standard. Visual acuity was examined and recorded following each HBO2 treatment administration. RESULTS: 10 eyes (five right, five left) of 10 patients) were included in the study. While average visual acuity was LogMAR 3 before the treatment, it was measured as LogMAR 1.8 on average after treatment (P ⟨ 0.05). None of the patients were observed to have neovascular glaucoma. CONCLUSIONS: HBO2 treatment is an efficacious method with few side effects and can be used in the treatment of CRAO patients. During acute and subacute periods a certain number of HBO2 treatment sessions may be beneficial. Stopping treatments before eight completed HBO2 sessions for a patient who did not show improvement until that time may miss a patient who would have benefited from HBO2 treatment.

Oxygen therapy in patients with retinal artery occlusion: A meta-analysis.

BACKGROUND: Oxygen therapy has been widely used for RAO (retinal artery occlusion) patients; however, inconsistent results have been reported. METHODS: PubMed, Web of Science, EMBASE, Medline (OvidSP), Cochrane, China National Knowledge Infrastructure (CNKI), and Wanfang Database were examined. The primary endpoint was visual acuity (VA), and RevMan software 5.3 was used to statistically analyze the outcomes. RESULTS: Seven randomized controlled trials (RCTs) met the inclusion criteria. Patients who received oxygen therapy exhibited probability of visual improvement about 5.61 times compared with the control group who did not receive oxygen therapy (OR = 5.61; 95% CI, 3.60-8.73; p < 0.01). No statistically significant difference was observed between oxygen inhalation methods (Chi2 = 0.18, df = 1, p = 0.67), combined therapy (Chi2 = 0.21, df = 1, p = 0.64), or RAO type (Chi2 = 0.06, df = 1, p = 0.81). Conversely, 100% oxygen (Chi2 = 4.55, df = 1, p < 0.05) and hyperbaric oxygen (Chi2 = 4.55, df = 1, p < 0.05) significantly improved VA in RAO patients. Better effect was showed in period within 3 months (Chi2 = 5.76, df = 1, p < 0.05). The most effective treatment length was over 9 hours (Chi2 = 6.58, df = 1, p < 0.05). CONCLUSION: Oxygen therapy demonstrated beneficial effects in improving VA in RAO patients, particularly when patients were treated with 100% hyperbaric oxygen and for over 9 hours.