The use of hyperbaric oxygen therapy in ophthalmology

The current alternative for ocular surface and anophthalmic socket reconstruction, cryopreserved umbilical amniotic membrane (cUAM)

PURPOSE

This report presents the results of using cryopreserved umbilical amniotic membrane (cUAM) as an alternative mucosal graft for ocular surface reconstruction in cases of anophthalmic socket contracture (ASC), cicatricial entropion (CE), and conjunctival-scleral defects.

METHODS

The study included patients who underwent non-commercial implantation of cUAM grafts (prepared by corneal banking methods) for ASC, CE, conjunctival defect, and scleral melting. The main success criteria for this study were the comfortable fitting of the ocular prosthesis in ASC patients, the natural eyelid position in CE patients, and the degree of conjunctivalisation in melting patients.

RESULTS

cUAM transplantation was performed in 2 patients who could not use a prosthetic eye due to conjunctival contracture, 2 patients with CE, and 1 patient with conjunctival defect and 1 patient with conjunctival-scleral melting. The primary outcome was achieved in 83.3% (5/6) of patients. In one patient with CE, partial healing was achieved due to the persistence of CE in the medial upper eyelid.

CONCLUSIONS

cUAM is a viable alternative to mucosal grafting for reconstructing the bulbar and palpebral conjunctival surface, fornix, and orbit, with reduced donor morbidity and shorter surgical time. Its regenerative ability allows for tissue defect healing and improves cosmetic appearance through epithelialization within weeks.

Hyperbaric Oxygen Therapy in Ophthalmology: A Narrative Review

Hyperbaric oxygen therapy (HBOT) has been used for the past 50 years for conditions such as decompression disease and wound healing. It has promising effects in the treatment of vision-threatening diseases, such as retinal artery occlusion, retinal vein occlusion, diabetic macular edema, and acute optic neuropathy; however, HBOT has not been approved for use in these conditions by regulatory authorities. This paper provides an overview of the theoretical effectiveness and most recent indications for HBOT in ophthalmology. The fundamental aspects of the physiology of choroidal circulation and metabolism are provided together with the clinical aspects that should be accounted for when selecting patients for this therapy. The paper also presents case reports of when HBOT was successfully implemented. The goals of this review were to explore the indications and benefits of HBOT and to evaluate the effectiveness of HBOT as an intervention in treating ophthalmology disorders. Lastly, the paper details the side-effects and discusses the safety issues of HBOT.

The effect of hyperbaric oxygen therapy on corneal endothelial structure and anterior segment parameters

PURPOSE

To assess the effect of hyperbaric oxygen therapy (HBOT) on corneal endothelial structure and anterior segment parameters in healthy eyes.

METHODS

17 eyes of 17 patients who were scheduled to receive HBOT for other than ophthalmologic indications were investigated in this prospective study. Central corneal thickness (CCT) and corneal endothelial properties were evaluated using a specular microscope. Endothelial cell density (ECD), average cell area (AVG), coefficient of variation in cell size (CV), percentage of hexagonal cells (HEX), CCT, intraocular pressure (IOP), spherical equivalent (SE), axial length (AL) and anterior chamber depth (ACD) values were measured before the HBOT, after the 1st session, and after the 20th session of therapy.

RESULTS

47% of the patients (n = 8) received HBOT because of avascular necrosis, 35% (n = 6) due to sudden hearing loss, 12% (n = 2) for diabetic foot, and 6% (n = 1) for wound infection. The mean IOP was 14,80 mmHg before HBOT, 14,20 mmHg after the 1st session, and 13,73 mmHg after the 20th session. The mean ACD was 3,38 mm before HBOT, 3,34 mm after the 1st session, and 3,16 mm after the 20th session. Although the mean IOP and ACD decreased after HBOT sessions, it was not statistically significant (p > 0.05). A significant reduction was observed in SE values after 20 sessions of HBOT compared to the values measured before HBOT (p = 0,009). The mean ECD was 2572,53 ± 261,51 cells/mm2 before HBOT, 2554,47 ± 236,13 after the 1st session, and 2563,13 ± 226,92 after the 20th session. When the corneal properties measured before and after HBOT sessions were compared, no significant difference was found in terms of CCT, ECD, AVG, CV, and HEX (p > 0.05).

CONCLUSION

We observed no significant change in CCT, corneal endothelial layer properties, and anterior segment morphology after the 1st session, and after the 20th session of HBOT. Although HBOT reduced IOP and ACD, it was not statistically significant. HBOT may lead to a significant decrease in SE values after the 20th session.

The Role of Hyperbaric Oxygen Therapy in the Treatment of Surgical Site Infections: A Narrative Review

Surgical site infections (SSIs) are among the most prevalent postoperative complications, with significant morbidity and mortality worldwide. In the past half century, hyperbaric oxygen therapy (HBOT), the administration of 100% oxygen intermittently under a certain pressure, has been used as either a primary or alternative therapy for the management or treatment of chronic wounds and infections. This narrative review aims to gather information and evidence supporting the role of HBOT in the treatment of SSIs. We followed the Scale for the Quality Assessment of Narrative Review Articles (SANRA) guidelines and scrutinized the most relevant studies identified in Medline (via PubMed), Scopus, and Web of Science. Our review indicated that HBOT can result in rapid healing and epithelialization of various wounds and has potential beneficial effects in the treatment of SSIs or other similar infections following cardiac, neuromuscular scoliosis, coronary artery bypass, and urogenital surgeries. Moreover, it was a safe therapeutic procedure in most cases. The mechanisms related to the antimicrobial activity of HBOT include direct bactericidal effects through the formation of reactive oxygen species (ROS), the immunomodulatory effect of HBOT that increase the antimicrobial effects of the immune system, and the synergistic effects of HBOT with antibiotics. We emphasized the essential need for further studies, especially randomized clinical trials and longitudinal studies, to better standardize HBOT procedures as well as to determine its full benefits and possible side effects.

Ocular surface reconstruction of Steven Johnson syndrome / toxic epidermal necrolysis affected eye - A case report

Introduction

Toxic epidermal necrolysis (TEN), also known as Steven Johnson syndrome (SJS), is a devastating disease. Patients develop blindness and symblepharon despite multiple reconstructive surgeries. We report a case of SJS/TEN with ocular involvement where treatment with hyperbaric oxygen therapy (HBOT) resulted in a significant improvement in the visual acuity after surgery.

Case presentation

A woman with SJS/TEN with severe ocular complication (SOC) had limbal stem cell deficiency and symblepharon of the superior and inferior fornix. Pannus grew over her cornea, reducing the vision to counting finger. The symblepharon produced shortening of the fornix, causing entropion. The in-turned eyelid caused her eyelashes to rub against the cornea, causing great damage to the ocular surface. Limbal stem cell deficiency led to the loss of normal corneal morphology and invasion of the pannus onto the central visual axis, resulting in poor vision. She experienced ocular inflammation for 3 months before transfer to our hospital for admission. Ophthalmic examination showed bilateral corneal opacity with conjunctivalization, and inferior and superior fornix shortening. Symblepharon-lysis with amniotic membrane transplantation was attempted but the outcome was poor, with recurrence of superior scaring and symblepharon. She finally underwent major reconstructive surgery with allogeneic limbal stem cell transplantation with her sister as the donor, autologous minor salivary gland transplantation, and oral buccal mucosa flap transplant. HBOT was given daily post-surgery for supporting the grafts and suppressing inflammation. After 17 HBOT sessions and 3 months of autoserum drops, her left eye vision increased from the initial counting finger to 0.4 due to the successful growth of the corneal epithelium from the donor corneal limbal cell line. When a scleral contact lens which vaulted over the corneal limbal area was fitted, her vision improved to 0.8 due to redressal of high order aberration and astigmatism from the cornea scar.

Conclusion

After major reconstruction of the ocular surface with multiple cell type transplants, including limbal stem cells, minor salivary gland acinar cells, and oral mucosa cells, HBOT proved useful in supporting the graft uptake and oxygenation of the donor tissues, enabling fast recovery of the grafts and cell functioning, with eventual return of the working vision of the patient.

The Impact of Different Oxygen Delivery Methods on Corneal Epithelial Repair after Injury

The hyperbaric oxygen therapy is often used in the management of acid and base burns of the eyes. However, oxygen is rarely supplied locally through goggles or face mask in ophthalmology. Therefore, in this study, we aim to investigate how oxygen delivery affects eye recovery after injury. We used a rabbit model with corneal epithelial injury to examine the effects of local oxygen supply via goggles or face mask on the recovery of cornea. A total of 75 healthy New Zealand white rabbits were randomly divided into three groups, A, B, and C, with 25 rabbits in each group. Then, on each rabbit eye (150 eyes in total), a circle of corneal epithelium with 5 mm in diameter was scraped off from the center of the cornea with a corneal epithelial scraper. Group A was given oxygen goggles every day (the oxygen flow rate was 3 L/min, once a day, 2 hours each time); group B was given nasal inhalation of oxygen every day (the oxygen flow rate was 3 L/min, once a day, 2 hours each time); and group C did not receive any treatment and was healed naturally. We found that the group A, which received oxygen supply via goggles, showed the best eye recovery. Transmission electron microscopy showed that the cornea with local oxygen supply via goggles or face mask exhibited intact capillary structure and obvious desmosome/hemidesmosome connections between cells. Moreover, the protein and RNA levels of hypoxia-related genes were lower in group A and B, suggesting that the hypoxia factor is a sensitive and early regulator in the low oxygen environment.

The effect of hyperbaric oxygen therapy on central macular thickness and choroidal thickness in the healthy eyes of patients with idiopathic sudden sensorineural hearing loss

PURPOSE

To evaluate the effect of hyperbaric oxygen therapy (HBOT) for idiopathic sudden sensorineural hearing loss (ISSNHL) on central macular thickness (CMT) and choroidal thickness (CT).

MATERIALS AND METHODS

The study included 42 healthy eyes of 21 patients with ISSNHL (aged 24-61 years) who started HBOT within the first three days of the onset of hearing loss. Duration and severity of hearing loss were noted before starting HBOT. Central macular thickness (CMT), choroidal thickness (CT) 1500 µm nasal and temporal of the fovea, and subfoveal CT were measured by spectral domain optic coherence tomography before the first session of HBOT and after sessions 10 and 20. measurements obtained before and after HBOT were compared.

RESULTS

Eleven patients (52.4%) were men and 10 (47.6%) were women. The mean age was 44.67 ± 10.1 years. The mean duration of sudden hearing loss before HBOT was 2.05 ± 1 day. Hearing loss was mild in 5 patients, moderate in 5 patients, moderate to severe in 2 patients, severe in 4 patients and profound in 5 patients. Comparison of measurements obtained before HBOT and after 10 and 20 sessions of HBOT revealed no significant differences in CMT (219.17 ± 22.91, 220.33 ± 19.66, and 220.21 ± 19.3 µm), subfoveal CT (347.71 ± 66.82, 348.38 ± 74.55, and 345.45 ± 75.39 µm), nasal CT (328.64 ± 82.31, 316.02 ± 79.32, and 313.52 ± 89.92 µm), or temporal CT (321.76 ± 71.29, 317.05 ± 73.94, and 314.05 ± 74.61 µm, respectively) (p > 0.05).

CONCLUSIONS

HBOT for the treatment of ISSNHL had no significant effect on CMT or CT in healthy eyes.

THE EFFECT OF HYPERBARIC OXYGEN THERAPY ON RETINA, CHOROIDAL THICKNESS, AND CHOROIDAL VASCULARITY INDEX

PURPOSE

To determine the acute and cumulative effect of hyperbaric oxygen therapy (HBOT) on retina and choroid tissue in healthy eyes.

MATERIAL AND METHODS

Thirty-five subjects who were planned to undergo HBOT for non-ophthalmologic indications comprised the population of this prospective study. Central macular thickness (CMT), retinal nerve fiber layer (RNFL), and choroidal thickness (CT) (3 points: subfoveal area, 500 µm nasal and fovea temporal) were measured using spectral-domain optical coherence tomography (SD-OCT) before HBOT and half an hour after the 1st and 20th sessions of HBOT. The subfoveal choroidal area was segmented using ImageJ software with the binarization technique on enhanced depth imaging (EDI) OCT images. Choroidal area (CA), luminal area (LA), and stromal area (SA) were calculated. Choroidal vascularity index (CVI) was determined as the ratio between LA and CA.

RESULTS

The right eyes of 35 patients aged between 22 and 59 years were enrolled in the study. The mean CMT values of the patients were 259.36 ± 22.31 µm, 256.94 ± 22.72 µm, and 254.58 ± 23.02 µm before HBOT, after the 1st session, and after the 20th session, respectively. The change in CMT values before and after HBOT was statistically significant (p=0.001). When the patients' RNFL, CT, CA, SA, LA, and CVI changes before and after the HBOT were examined, no statistically significant difference was found (p>0.05).

CONCLUSIONS

Our study is the first to jointly evaluate the effect of HBOT on the vascular and stromal components of the choroid and macula in healthy eyes. Due to its thinning effect on the macula, it can be preferred as an adjunctive and facilitating treatment option in addition to current treatments in patients with macular edema due to retinal vascular disorders.

Radiation retinopathy intricacies and advances in management

Background: Radiation retinopathy is a chronic, progressive, vision-threatening complication from exposure to various radiation sources. While several treatment modalities are available, proper management for this disease is a continuing challenge with no consensus on the most efficacious.Objective: The aim of this article is to provide an updated review of the published literature on the course of the disease, available treatments and their efficacies, frequency of regimen, core issues in patient management, and additional newer treatment modalities, including possible prophylactic approaches.Value: We also highlighted the challenges encountered with managing chronically treated patients through an analysis of a clinical case report on a patient who was treated for several years with different modalities after a diagnosis of radiation retinopathy.

Impact of Different Oxygen Supply Methods on the Healing of Corneal Epithelial Wound and the Level of Acetylcholine

Purpose

To investigate the impact of different oxygen supply methods on corneal epithelial wound healing and acetylcholine level during wound healing.

Methods

We randomly divided 75 rabbits into three groups: A, B, and C, with 25 rabbits in each group. The central corneal epithelium was removed from all eyes of the rabbits using a 5 mm trephine. Group A rabbits were given low flow oxygen (3 L/min; concentration: 33%) for 2 h per day through goggles. Group B rabbits were given low flow oxygen (3 L/min; concentration: 33%) for 2 h per day via oxygen masks for inhalation. Group C rabbits healed naturally. The area of healed corneal epithelium and acetylcholine content in corneal epithelium were determined at 12 h, 24 h, and 36 h after injury.

Results

At 12 h, 24 h, and 36 h after injury, the healing area of corneal epithelium in the three groups was in the order group A > group B > group C (P < 0.05). At all timepoints, the acetylcholine level in corneal epithelium was in the order of group A > group B > group C (P < 0.05). In all three groups, the acetylcholine content in corneal epithelium showed the order 12 h > 24 h > 36 h (P < 0.05). There was a correlation between acetylcholine expression and the area of unhealed corneal epithelium, and the correlation coefficients of groups A, B, and C were 0.80, 0.83, and 0.85 respectively.

Conclusion

Increasing oxygen concentration through inhalation or via goggles can promote corneal epithelial wound healing, but increasing local oxygen concentration of the eye showed a better effect. Acetylcholine may play an important role in the early process of corneal epithelial wound healing.

Hyperbaric Oxygen Therapy for Central Retinal Artery Occlusion: Patient Selection and Perspectives

The central retinal artery occlusion (CRAO) is a rare ophthalmological emergency that can occur in the eye. CRAO can affect persons of any age, however it is most common in people over the age of 60. CRAO is associated with a number of risk factors, including giant cell arteritis, carotid artery atherosclerosis, cardiogenic emboli, hypertension, smoking, diabetes, and thromboembolic disease. The chance of each of these etiologies being present is assessed during the course of the investigation. Hyperbaric oxygen treatment (HBOT) is classified by the American Heart Association for CRAO at level IIb. In accordance with that, HBOT might be considered for the treatment of such a severe condition. HBOT can maintain retinal oxygenation during ischemic events by allowing oxygen to diffuse through choroidal capillaries that have been exposed to elevated partial pressures of oxygen. As a result, ischemia-related damage is reversed if applied within proper time frame. The amount of time that has passed prior to initiation of HBOT is considered to be the most critical factor in determining the best visual prognosis. According to the Undersea and Hyperbaric Medical Society, patients who are identified with CRAO after the onset of symptoms should be evaluated for HBOT within 24 hours. HBOT has the advantage of having a low risk profile, and it can be utilized to improve visual outcomes in proper patients.

Rapid reduction of macular edema due to retinal vein occlusion with low-dose normobaric hyperoxia

PURPOSE

We investigated the effects of a relatively inexpensive, non-invasive, short-term treatment with low-dose normobaric hyperoxia (NBH) on macular edema in patients with retinal vein occlusion (RVO).

METHODS

Participants with macular edema associated with RVO were treated with 5 LPM of NBH via facemask (40% fraction of inspired oxygen, FIO2) for 3 h. Patients with non-fovea involving edema who elected to be observed returned for a second treatment 1 month later to test reproducibility.

RESULTS

A 3-h session of NBH (n = 45) resulted in decreased maximum macular thickness (MMT) (mean 7.10%, t₃₄=9.63 P<.001) and central macular thickness (CMT) (mean 4.64%, t₃₄=6.90, P<.001) when compared to untreated eyes with RVO measured over the same period of time (n = 12) or their healthy fellow eye (n = 34; MMT:t₃₄=-9.60, P<.001;CMT: t₃₄=-6.72, P<.001). Patients who had a second NBH treatment 1 month later experienced a recurrence of their edema, but demonstrated a similar significant reduction in MMT and CMT after the second NBH treatment.

CONCLUSIONS

Three-hour treatment with 40% FIO2 NBH results in a significant reduction in MMT and CMT. This study supports an ischemic mechanism for macular edema associated with retinal vein occlusion.

TRANSLATIONAL RELEVANCE

Short-term low-dose normobaric hyperoxia is a simple, inexpensive, and ubiquitous treatment that may provide an alternate or adjunctive approach to treating macular edema in patients who are resistant to or cannot afford anti-VEGF medications.

Unilateral Orbital Emphysema Secondary to Vitreoretinal Surgery

PURPOSE

To describe preoperative, intraoperative, and postoperative characteristics, imaging findings, and clinical evolution of patients who developed orbital emphysema after vitreoretinal surgery.

DESIGN

Retrospective, descriptive, observational case series.

PARTICIPANTS

Patients with orbital emphysema after vitreoretinal surgery who were diagnosed and treated between January 2006 and October 2018 at a single ophthalmology referral center.

METHODS

Medical records and orbital computed tomography images were reviewed and analyzed. A minimum follow-up of 3 months was required.

MAIN OUTCOME MEASURES

Final best-corrected visual acuity (BCVA).

RESULTS

This study included 16 patients with a mean age of 47.9 ± 14.7 years, 50% were women, and 25% had a history of previous ocular trauma. A diagnosis of rhegmatogenous retinal detachment was established in 75% of patients. Twenty-five percent of patients underwent pars plana vitrectomy (PPV), 50% underwent encircling scleral buckling plus PPV, 18.8% underwent repeat PPV, and 6.2% underwent scleral buckling plus repeat PPV. Additionally, 62.5% received silicone oil endotamponade. The median time between vitreoretinal surgery and orbital emphysema was 8 days (interquartile range [IQR] 5-15 days). Mean proptosis was 6.7 ± 4.6 mm. Orbital cellulitis was considered as a differential diagnosis in 31.2% of patients, and tomographic evidence of fracture was observed in 25% of patients. Treatment with compressive patching was prescribed for 87.5% of patients, transpalpebral drainage was prescribed for 75% of patients, hyperbaric oxygen therapy was prescribed for 43.8% of patients, and surgical management was prescribed for 31.2% of patients. The comparison between BCVA before vitreoretinal surgery (median, 1.8 logarithm of the minimum angle of resolution [logMAR]; IQR, 1.33-2.3 logMAR) and at the last follow-up (median, 2.3 logMAR; IQR, 1.42-2.8 logMAR) was not statistically significant (P = 0.125, Wilcoxon matched-pairs signed-rank test). No association was found between surgeon experience and lower final BCVA (P = 0.604, Fisher exact test); however, development of ocular hypertension was associated with worse final BCVA (P = 0.0101; relative risk, 7; 95% confidence interval, 1.01-44.63).

CONCLUSIONS

Although orbital emphysema constitutes a very unusual complication of vitreoretinal surgery, it is important to identify this condition promptly and treat patients efficiently to avoid potential vision loss.

The effect of hyperbaric oxygen therapy on retinal thickness and progression of retinopathy in patients with Type 2 diabetes: a prospective cohort study

Purpose: Evaluation of the effect of hyperbaric oxygen therapy (HBOT) on the progression of retinopathy, choroidal and retinal thickness in patients with type 2 diabetes mellitus (DM). Materials and methods: This prospective non-randomized cohort study consisted of 60 eyes of 30 patients who received 30 sessions of HBOT for a diabetic foot ulcer (DFU). The participants were divided into three groups; group 1: mild-moderate non-proliferative diabetic retinopathy (DRP) (n = 14), group 2: severe non-proliferative DRP (n = 20) and group 3: DRP without active proliferative findings with the applied laser for at least 2 years (n = 26). The cases were examined on base-line (measurement-1), after the 10th session of HBOT (Measurement-2), after the 20th session of HBOT (Measurement-3), after the 30th session of HBOT (Measurement-4), and after 10 days of the last session of HBOT (Measurement-5). The changes in central macular thickness (CMT; subfoveal point [CMT-SF], nasal point [CMT-N] and temporal point [CMT-T]), central choroidal thickness (CCT; subfoveal point [CCT-SF], nasal point [CCT-N] and temporal point [CCT-T]), and the stage of DRP were compared. Results: There was no significant difference between groups in terms of change ratio (CR%) in CMT-SF and CMT-N values. However, in Measurement-3, CR% in CMT-T was significantly higher in group 1 (p = 0.019). A significant increase in CMT-N and CMT-T parameters over time was observed in Group 1 (p < 0.05). There was a significant decrease in CCT-SF, CCT-N, and CCT-T values with time in each of the three groups (p < 0.05). At the end of HBOT, there was no progression or regression in the stage of DRP in any group. Conclusions: HBOT has both a thinning effect on the choroid layer in all three groups and a thickening effect on the macula in the mild-moderate non-proliferative diabetic eyes.

Reactive oxygen species, oxidative stress, glaucoma and hyperbaric oxygen therapy

This review examines the role of oxidative stress in damage to cells of the trabecular meshwork and associated impaired aqueous drainage as well as damage to retinal ganglion cells and associated visual field losses. Consideration is given to the interaction between vascular and mechanical explanations for pathological changes in glaucoma. For example, elevated intraocular pressure (IOP) forces may contribute to ischaemia but there is increasing evidence that altered blood flow in a wider sense is also involved. Both vascular and mechanical theories are involved through fluctuations in intraocular pressure and dysregulation of blood flow. Retinal function is very sensitive to changes in haemoglobin oxygen concentration and the associated variations in the production of reactive oxygen species. Reperfusion injury and production of reactive oxygen species occurs when IOP is elevated or blood pressure is low and beyond the capacity for blood flow autoregulation to maintain appropriate oxygen concentration. Activities such as those associated with postural changes, muscular effort, eye wiping and rubbing which cause IOP fluctuation, may have significant vascular, mechanical, reperfusion and oxidative stress consequences. Hyperbaric oxygen therapy exposes the eye to increased oxygen concentration and the risk of oxidative damage in susceptible individuals. However, oxygen concentration in aqueous humour, and the risk of damage to trabecular meshwork cells may be greater if hyperbaric oxygen is delivered by a hood which exposes the anterior ocular surface to higher than normal oxygen levels. Oronasal mask delivery of hyperbaric oxygen therapy appears to be indicated in these cases.

Orbital Emphysema as a Rare Complication of Retina Surgery

Three patients with a history of previous pars-plana vitrectomy, 2 of them with perfluoropropane, and 1 with sulfur hexafluoride used, experienced eyelid swelling and pain after travelling to a higher altitude city. Gas was found in the orbit and periocular tissues, causing orbital compartment syndrome in 2 of the patients. The gas persisted on these patients despite surgical intervention, so hyperbaric oxygen therapy was advised. One patient refused, the other patient responded well to this therapy and the gas disappeared. The patient without an orbital compartment syndrome made a full recovery without needing medical or surgical intervention.

Adjunctive Therapies for Bacterial Keratitis

Bacterial keratitis is the most common type among all types of infectious keratitis. Currently, antibiotics are the main-stay of treatment. The objective of this systematic review is to review published clinical studies which discuss the adjunctive treatment of bacterial keratitis to guide clinical decision-making. We reviewed the role of a variety of medications and surgeries which can help in managing bacterial keratitis complications, which include as thinning, perforation, and impaired wound healing. We have included appropriate animal and laboratory studies, case reports and case series, and randomized clinical trials regarding each therapy.

Rescue vitrectomy with blocked artery massage and bloodletting for branch retinal artery occlusion

A 61-year-old male suffered from sudden blurred vision and superior visual field defect oculus dexter. His vision was counting fingers at 20 cm. Fundoscopy demonstrated inferior pale retina and a large embolus located at the proximal inferior retinal artery. Branch retinal artery occlusion (BRAO) was diagnosed. Initial paracentesis, topical brimonidine tartrate, oral pentoxifylline, and hyperbaric oxygen therapy were performed but showed limited improvement. Hence, he received 25-gauge vitrectomy, artificial posterior vitreous detachment, blocked retinal artery massage, and bloodletting 5 days after onset. After the surgery, his vision improved to 20/25. Fundoscopy showed reperfused retina, and optical coherence tomography revealed resolved retinal edema. RAO is an ophthalmological emergency; however, no standard guideline is available. Vitrectomy with blocked retinal artery massage and bloodletting showed favorable results in this case of BRAO with a large embolus. More prospective clinical trials are needed for setting up the standard treatment.

The efficacy of hyperbaric oxygen therapy in the treatment of central retinal artery occlusion

Central retinal artery occlusion (CRAO) is an ophthalmological emergency. Various treatment modalities have been tried, but none have shown to alter natural history of the disease. Hyperoxia can restore retinal oxygenation, and favourable results were obtained with hyperbaric oxygen therapy (HBOT). We report two patients with sudden visual loss due to CRAO treated with HBOT. Case 1: a 61-year-old female, presented with CRAO in her left eye(OS). She was submitted to eight sessions of HBOT(2.4atmosphere absolute (ATA)). BCVA(Best corrected visual acuity) improved from counting fingers (CF) to 1.0 and fluorescein angiography (FA) showed a normalisation. Vascular study showed a value of 8.8% for HbA1c and ventricular extrasystoles. Case 2: a 69-year-old male presented with CRAO in his OS. Nine sessions of HBOT(2.4 ATA) were performed. Best corrected visual acuity (BCVA)improved from CF to 0.8 and the FA was normalised. Vascular study revealed an atheromatous carotid disease, and cardiac pathology. HBOT seems to be beneficial on the recovery of vision following CRAO.

Retinal oxygen: from animals to humans

This article discusses retinal oxygenation and retinal metabolism by focusing on measurements made with two of the principal methods used to study O₂ in the retina: measurements of PO₂ with oxygen-sensitive microelectrodes in vivo in animals with a retinal circulation similar to that of humans, and oximetry, which can be used non-invasively in both animals and humans to measure O₂ concentration in retinal vessels. Microelectrodes uniquely have high spatial resolution, allowing the mapping of PO₂ in detail, and when combined with mathematical models of diffusion and consumption, they provide information about retinal metabolism. Mathematical models, grounded in experiments, can also be used to simulate situations that are not amenable to experimental study. New methods of oximetry, particularly photoacoustic ophthalmoscopy and visible light optical coherence tomography, provide depth-resolved methods that can separate signals from blood vessels and surrounding tissues, and can be combined with blood flow measures to determine metabolic rate. We discuss the effects on retinal oxygenation of illumination, hypoxia and hyperoxia, and describe retinal oxygenation in diabetes, retinal detachment, arterial occlusion, and macular degeneration. We explain how the metabolic measurements obtained from microelectrodes and imaging are different, and how they need to be brought together in the future. Finally, we argue for revisiting the clinical use of hyperoxia in ophthalmology, particularly in retinal arterial occlusions and retinal detachment, based on animal research and diffusion theory.

Early Onset of Ocular Neovascularization After Hyperbaric Oxygen Therapy in a Patient With Central Retinal Artery Occlusion

Central retinal artery occlusion (CRAO) is an infarction to the retina that results in acute, frequently severe vision loss. Long-term complications such as ocular neovascularization (ONV) can occur and result in neovascular glaucoma and vitreous hemorrhage. Recent studies have explored acute hyperbaric oxygen (HBO) therapy as a promising treatment for CRAO to improve long-term vision potential; however, its effects on CRAO complications have not been well characterized. This study was conducted to better characterize the effects of HBO therapy on complications from CRAO. We present a unique case of ONV in an eye within 1 month after successfully completing acute HBO therapy for a CRAO, highlighting the importance of routine monitoring in this unique population.

The effect of high-dose steroids, and normobaric oxygen therapy, on recent onset non-arteritic anterior ischemic optic neuropathy: a randomized clinical trial

BACKGROUND

To evaluate the effect of high-dose intravenous steroids, as well as normobaric oxygen therapy, in the management of recent onset non-arteritic anterior ischemic optic neuropathy (NAION).

METHOD

Ninety eyes of 90 patients diagnosed with NAION within 14 days of onset were included in this single masked randomized clinical trial. Thirty patients were randomized into each set as group 1 (control), group 2 (steroids), and group 3 (oxygen). Controls received placebo; group 2 received methylprednisolone 500 mg twice a day for 3 days followed by 2 weeks of oral prednisolone 1 mg/kg/day; group 3 received 100 % normobaric oxygen with mask, at a flow rate of 5 liters per minute for 1 hour twice a day for two weeks. Functional and structural outcomes were analyzed at 1 and 6 months following treatment. Best corrected visual acuity (BCVA) was the main outcome measure, and mean deviation (MD) of visual field (VF) test and peripaillary retinal nerve fiber layer thickness (PRNFLT) were secondary outcome measures.

RESULTS

The mean BCVA at the time of presentation was 1.02 ± 0.63, 1.05 ± 0.7, and 0.76 ± 0.5 LogMAR in groups 1, 2, and 3, respectively (p = 0.293); corresponding values were 0.8 ± 0.45, 0.84 ± 0.45, and 0.58 ± 0.4 at month 1 (p = 0.127, 0.19, and 0.168, respectively). BCVA improved to 0.71 ± 0.46, 0.73 ± 0.36, and 0.59 ± 0.41 LogMAR at the 6-month follow-up point (p = 0.039, 0.048, and 0.195, respectively). The mean deviation (MD) at the time of presentation was 19.26 ± 7.02, 20.51 ± 4.68, and 19.3 ± 7.17 in the control, steroid, and oxygen groups, respectively (p = 0.65). Corresponding values at month 1 were 20.26 ± 8.52, 19.52 ± 7.08, and 18.3 ± 7.45, (p = 0.656); and at month 6 were 18.42 ± 8.17, 17.66 ± 6.44 and 16.53 ± 6.32, respectively (p = 0.635). PRNFLT at presentation was 166 ± 57, 184 ± 57, and 193 ± 65 micrometer in the control, steroid, and oxygen groups, respectively (p = 0.265); which decreased to 73 ± 11, 87 ± 26, and 79 ± 19 at the final foll-w up (all p < 0.001). There were no statistically significant differences between the three groups in terms of final visual function and structure.

CONCLUSION

The lack of demonstrable improvement in the structural and functional outcomes of NAION with high-dose IV steroids, or normobaric oxygen, in this randomized controlled trial calls into question the administering of systemic steroid or normobaric oxygen in this condition.

Management of orbital emphysema secondary to rhegmatogenous retinal detachment repair with hyperbaric oxygen therapy

Purpose

To describe the case of orbital subcutaneous emphysema who was successfully treated with hyperbaric oxygen therapy.

Observations

Case report. Retrospective analysis of medical records and computer tomography images. A 40 years-old female, with retinal detachment who was seen at the emergency department, two weeks after undergoing a combined procedure of pars plana vitrectomy, scleral buckle and Sulfur hexafluoride tamponade. The patient complained of pain, decrease eye movement and edema of the upper eyelid. Clinical examination revealed periorbital crepitus. She was treated immediately with soft tissue decompression with small-gauge needle. Orbital emphysema recurred quickly, indicating possible gas trapped in the soft tissue. Using the US NAVY decompression protocol we were able to achieve fast clinical improvement. The protocol was repeated in several occasions until complete resolution.

Conclusion and importance

Hyperbaric oxygen therapy is an effective treatment for orbital and periorbital emphysema, due to its property of helping accelerate N₂ elimination from adipose tissue.

Systemic oxygen therapy versus oral enalapril for treatment of diabetic macular ischemia: a randomized controlled trial

The purpose of this study was to evaluate the structural and functional effects of systemic oxygen therapy and enalapril in patients with diabetic macular ischemia (DMI). This randomized clinical trial consisted of 105 eyes with DMI divided into three groups. Group I received systemic oxygen by face mask at a flow rate of 10 L/min; Group II received 5 mg enalapril daily; and Group III received placebo tablets for 3 months. Best-corrected visual acuity (BCVA), central macular thickness (CMT) measured by optical coherence tomography (OCT), extent of foveal avascular zone (FAZ) on fluorescein angiograms, and electroretinograms (ERG) were obtained at baseline and after 3 and 6 months. Overall, 102 patients completed the study. Baseline characteristics were not significantly different among groups. Significant improvement in BCVA and decrease in CMT and FAZ occurred at months 3 and 6 in oxygen group compared to deterioration in enalapril and control groups (All P values <0.001). ERG parameters were significantly better in oxygen group compared to enalapril group at months 3 and 6 and better than those in control group at month 3. Normobaric oxygen therapy for 3 months in DMI decreased CMT and FAZ and improved BCVA and ERG parameters. Enalapril did not show any favorable effect.

Hyperbaric oxygen therapy in branch retinal artery occlusion in a 15-year-old boy with methylenetetrahydrofolate reductase mutation

Purpose. To report the efficacy of hyperbaric oxygen (HBO) therapy in a case of branch retinal artery occlusion (BRAO) in a 15-year-old boy. Methods. We report a 15-year-old boy with sudden loss of vision due to BRAO. Examination included laboratory evaluation for systemic risk factors. Follow-up exams included visual acuity, fundus examination, fundus fluorescein angiography, and visual field testing. HBO therapy was employed for treatment. Results. Medical history was positive for isolated glucocorticoid deficiency. Laboratory evaluation disclosed hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) mutation. The visual acuity 0.05 at presentation improved to 0.8 after 20 days of HBO therapy. There was no change on visual fields. Conclusion. In this pediatric case, HBO therapy was useful in the treatment of BRAO.

Hyperbaric oxygen therapy in combination with systemic treatment of sickle cell disease presenting as central retinal artery occlusion: a case report

Introduction

We describe hyperbaric oxygen therapy for the treatment of central retinal artery occlusion in a young adult with sickle cell disease.

Case presentation

A 25-year-old Turkish man with a history of sickle cell disease developed sudden painless loss of vision in the left eye and was hospitalized for diagnosis and treatment. Central retinal artery occlusion was diagnosed with retinal whitening, cherry red spot, and delayed arteriovenous transit on fluorescein angiography. He underwent exchange transfusion and hyperbaric oxygen therapy. In the following three months, his visual acuity improved to 20/30.

Conclusions

In this present case with sickle cell disease, the visual acuity improved with hyperbaric oxygen therapy in addition to systemic therapy. The result of our case suggests that hyperbaric oxygen therapy may be beneficial in the treatment of central retinal artery occlusion.

Hyperbaric oxygen therapy and the possibility of ocular complications or contraindications

Hyperbaric oxygen therapy increases oxygen pressure and the concentration of reactive oxygen species in blood and tissues. Increased oxygen pressure may be beneficial in some diseases, such as in the treatment of diabetic leg ulcers and diabetic retinopathy; however, due to their cytotoxic properties, an excess of reactive oxygen species in tissues and/or deficiencies in antioxidant activity, may contribute to complications of hyperbaric oxygen therapy, such as cataract. This review examines the possibility that increased tissue concentrations of reactive oxygen species may also exacerbate other ocular diseases. For example, reactive oxygen species and deficiencies in antioxidant activities contribute to the pathogenetic processes in keratoconus. Such impact may be exacerbated by exposure to additional reactive oxygen species during hyperbaric oxygen therapy. The senescent eye may be particularly prone to oxidative damage as exemplified by conditions such as macular degeneration and cataract. Because of its high consumption of oxygen, the retina is particularly susceptible to oxidative stress, which plays a major role in retinopathy. For example, under normal conditions age-related macular degeneration involves oxidative stress and death of the retinal pigment epithelial cells. Hyperbaric oxygen therapy may exacerbate these processes. In addition to cataract, age-related macular degeneration and keratoconus, there may be other ocular diseases for which exposure to hyperbaric oxygen therapy-related oxidative stress may be significantly adverse. In all such cases, careful pre-examination and evaluation of the potential risk and benefit from this form of therapy appears to be warranted. Unless it could interfere with the benefits of hyperbaric oxygen therapy, antioxidant dietary supplementation may be indicated in conjunction with any hyperbaric oxygen therapy, when there are co-existing diseases for which oxidative stress could have significantly adverse side effects. Delivery of hyperbaric oxygen therapy may need to be modified or it may even be contraindicated in these cases.

Partial vision recovery after iatrogenic retinal artery occlusion

Background

To describe the first case of partial vision recovery in a 32-year-old woman with iatrogenic retinal artery occlusion (RAO) following glabella calcium hydroxylapatite (CaHA) injection, and to explore appropriate diagnostic and therapeutic measures according to a literature review.

Case presentation

A 32-year-old woman had left eye RAO and a bilateral visual field defect after CaHA injection into the glabella region. Topical and systemic intraocular pressure lowering agents, isovolemic hemodilution, globe massage, and anticoagulation with acetylsalicylic acid were prescribed. Carbogen inhalation and oral corticosteroids were also given. In addition to the above therapies, hyperbaric oxygen therapy (HBOT) was implemented as adjuvant treatment. The final best corrected visual acuity (BCVA) of the left eye improved from hand motion at 15 cm to 0.1. Improved retinal circulation and decreased retinal vessel leakage were found in the follow-up fluorescein angiography. However, there were still multiple emboli in the conjunctival and retinal arteries.

Conclusion

This is the first case report on partial recovery of BCVA after iatrogenic RAO following cosmetic CaHA injection. Because no reliable treatments have been reported for such complications, HBOT may be considered as an alternative adjuvant therapy.

Effects of hyperbaric oxygen on crystalline lens and retina in nicotine-exposed rats

OBJECTIVE

To determine histopathological changes on crystalline lens and retina of rats after subcutaneous injection of nicotine and to examine the effects of hyperbaric oxygen (HBO) on these changes related to nicotine exposure.

METHODS

Twenty-eight female Sprague-Dawley rats were enrolled in the study and the rats were divided into four equal sized groups randomly (Group N: the rats exposed only to nicotine, group HB: the rats received only HBO, group N+HB: the rats that underwent to nicotine injection and subsequently received HBO, group C: the control group that neither exposed to nicotine nor received HBO). The rats were sacrificed by decapitation method and all were enucleated immediately after scarification. Tissue samples from crystalline lens, lens capsule, and the retina from the right eyes of the rats were examined by light microscopy.

RESULTS

While the histological appearances of the retina and the lens was similar in group HB, group N+HB, and the control group; group N showed some pathological changes like decrement in the retinal ganglion cell density, atrophy of the retinal nerve fiber layer, congestion of the vessels in the optic nerve head, thinning of the internal plexiform layer, thinning of the lens capsule, and transformation of the anterior subcapsular epithelium into squamous epithelia.

DISCUSSION

Subcutaneous injection of nicotine was found to be related with some pathological changes in the retina and lens of the Sprague-Dawley rats. However HBO caused no significant negative effect. Furthermore, the histopathological changes related to nicotine exposure in the lens and retina of the rats recovered by the application of HBO.

Delayed response of the retina after hyperbaric oxygen exposure

PURPOSE

To examine retinal electrophysiological function and retinal thickness in healthy eyes before and after hyperbaric oxygen (HBO) exposure.

METHODS

The healthy eye in each of six subjects who underwent experimental HBO treatment for branch retinal vein occlusion in the fellow eye was examined using multifocal electroretinography (mfERG) and optical coherence tomography (OCT) at baseline and following a course of five consecutive daily sessions of exposure to HBO at 2.4 atmospheres of absolute pressure lasting 90 min each.

RESULTS

After HBO, P1 implicit times of the mfERG were significantly shorter than at baseline. The response was delayed, being undetectable on the day treatment concluded, whereas a 2.65% reduction in implicit time was seen 1 week later (p = 0.032). The P1 implicit time remained 2.49% shorter than at baseline 1 month after the end of the HBO sessions (p = 0.020). The bulk of the response to HBO was found in the foveal and parafoveal regions. No detectable change was seen in mfERG amplitudes or in the volume or thickness of the retina.

CONCLUSION

A mfERG component related to bipolar and Müller cell function was accelerated by a short intermittent exposure to HBO. The response developed after the end of the HBO exposure and lasted for at least 3 weeks, suggesting that it was prompted by the withdrawal of HBO rather than the onset and subsequent brief exposure to HBO.

Hyperoxia therapy of pre-proliferative ischemic retinopathy in a mouse model

PURPOSE

To investigate the therapeutic use and mechanisms of action of normobaric hyperoxia to promote revascularization and to prevent neovascularization in a mouse model of oxygen-induced ischemic retinopathy.

METHODS

Hyperoxia treatment (HT, 40%-75% oxygen) was initiated on postnatal day (P) 14 during the pre-proliferative phase of ischemic retinopathy. Immunohistochemistry, ELISA, and quantitative PCR were used to assess effects on retinal vascular repair and pathologic angiogenesis in relation to glial cell injury, VEGF protein, and mRNA levels of key mediators of pathologic angiogenesis. Effects of intravitreal injections of VEGF and the VEGF inhibitor VEGFR1/Fc fusion protein were also studied.

RESULTS

Administration of HT during the ischemic pre-proliferative phase of retinopathy effectively accelerated the process of revascularization while preventing the development of vitreous neovascularization. HT enhanced the formation of specialized endothelial tip cells at the edges of the repairing capillary networks and blocked the overexpression of several molecular mediators of angiogenesis, inflammation, and extracellular proteolysis. HT markedly reduced the reactive expression of GFAP in Müller cells and improved the morphology of astrocytes in the avascular region of the retina. Exogenous VEGF administered into the vitreous on P14 was not sufficient to cause vitreous neovascularization in the HT mice. Injection of the VEGF antagonist VEGFR1/Fc blocked both pathologic and physiological angiogenesis and did not rescue astrocytes.

CONCLUSIONS

HT may be clinically useful to facilitate vascular repair while blocking neovascularization in the pre-proliferative stage of ischemic retinopathy by correcting a broad range of biochemical and cellular abnormalities.

Oxygen therapy for acute ocular chemical or thermal burns: a pilot study

PURPOSE

To evaluate the effect of systemic oxygen therapy in the management of acute ocular chemical and thermal burns.

DESIGN

Prospective, nonrandomized, comparative, interventional case series.

METHODS

Twenty-four eyes of 22 patients with grade III to IV acute ocular chemical and thermal burns received conventional medical therapy. The oxygen therapy group (13 eyes) additionally received 100% oxygen using a simple mask at a flow rate of 10 L/minute for 1 hour twice daily. Main outcome measures were time for healing of the corneal epithelial defect and improvement in perilimbal ischemia. Secondary outcome measures included visual acuity, corneal transparency and vascularization, and complications.

RESULTS

Corneal epithelial defects healed within 15.23 ± 3.94 days (range, 10 to 21 days) in the oxygen group versus 59.9 ± 23.33 days (range, 28 to 95 days) in controls (P < .001). Vascularization of ischemic areas was complete in 14.54 ± 2.70 days (range, 10 to 21 days) in the oxygen group versus 45.09 ± 22.20 days (range, 25 to 105 days) in controls (P = .001). In the oxygen group, the cornea was more transparent and less vascularized 3 and 6 months after injury. Mean final visual acuity (logarithm of the minimal angle of resolution) was 0.40 ± 0.52 (range, 0 to 1.3) versus 1.11 ± 0.83 (range, 0.1 to 3) in the oxygen and control groups, respectively (P = .018). In the oxygen group, symblepharon or corneoscleral melting did not develop in any patient; however, in the control group, symblepharon developed in 3 eyes and corneoscleral melting developed in 1 patient.

CONCLUSIONS

In the acute phase of ocular chemical or thermal burns, oxygen therapy improves limbal ischemia, accelerates epithelialization, increases corneal transparency, and decreases corneal vascularization. It also may improve visual acuity and reduce complications.

Neuroprotective effect of hyperbaric oxygen therapy on anterior ischemic optic neuropathy

The study investigated the therapeutic effect of hyperbaric oxygen (HBO) on anterior ischemic optic neuropathy in a rodent model (rAION). rAION was laser-induced in one eye of 63 mice. The fellow (uninjured) eye served as an internal control. Thirty-three mice underwent two 90-min sessions of 100% oxygen (2 atm) treatment immediately following injury and one session daily thereafter for up to 14 days. The remaining mice were untreated. Retinas were harvested at different time points, and mRNA levels of various genes were analyzed by real-time polymerase chain reaction and histologic study. Untreated mice: day 1 post-rAION – SOD-1 (oxidative-stress-related) decreased to 82% of control (uninjured eye) levels (P < 0.05), Caspase-3 (proapoptotic) decreased to 89%, Bcl-xL mildly increased (117%; all NS); day 3 – HO-1 and endothelial nitric oxide synthase (eNOS; ischaemia-related) decreased to 74%, and Bcl-2-associated X protein, Caspase-3, and B-cell lymphoma 2 (Bcl-2; apoptotic) increased by 170, 120, and 111%, respectively (all NS); day21 – HO-1 increased to 222% (NS) and eNOS decreased to 48% (P < 0.05). Treated mice: day 1 – SOD-1 and Caspase-3 remained unchanged, Bcl-2 and Bcl-xL mildly increased (112 and 126% respectively); day 3 – HO-1 and eNOS increased, apoptosis-related gene decreased; day 21 – SOD-1 decreased whereas eNOS increased (P < 0.05), and HO-1 increased to a lesser degree than without treatment. None of the oxygen-treated animals had retinal ganglion cell loss or a decrease in Thy-1 expression. In conclusion, HBO treatment after rAION induction influences the expression of apoptosis-related genes as well as oxidative-stress-induced and ischaemia-related genes and may exert a neuroprotective effect.

Current treatments for radiation retinopathy

BACKGROUND

to review the currently available therapeutic modalities for radiation retinopathy (RR), including newer investigational interventions directed towards specific aspects of the pathophysiology of this refractory complication.

METHODS

a review of the literature encompassing the pathogenesis of RR and the current therapeutic modalities available was performed.

RESULTS

RR is a chronic and progressive condition that results from exposure to any source of radiation. It might be secondary to radiation treatment of intraocular tumors such as choroidal melanomas, retinoblastomas, and choroidal metastasis, or from unavoidable exposure to excessive radiation from the treatment of extraocular tumors like cephalic, nasopharyngeal, orbital, and paranasal malignancies. After the results of the Collaborative Ocular Melanoma Study, most of the choroidal melanomas are being treated with plaque brachytherapy increasing by that the incidence of this radiation complication. RR has been reported to occur in as many as 60% of eyes treated with plaque radiation, with higher rates associated with larger tumors. Initially, the condition manifests as a radiation vasculopathy clinically seen as microaneurysms and telangiectases, with posterior development of retinal hard exudates and hemorrhages, macular edema, neovascularization and tractional retinal detachment. Regrettably, the management of these eyes remains limited. Photodynamic therapy, laser photocoagulation, oral pentoxyphylline and hyperbaric oxygen have been attempted as treatment modalities with inconclusive results. Intravitreal injections of anti-vascular endothelial growth factor such as bevacizumab, ranibizumab and pegaptanib sodium have been recently used, also with variable results.

DISCUSSION

RR is a common vision threatening complication following radiation therapy. The available therapeutic options are limited and show unsatisfactory results. Further large investigative studies are required for developing better therapeutic as well as preventive treatment strategies.

Use of adjuvant hyperbaric oxygen therapy to support limbal conjunctival graft in the management of recurrent pterygium

PURPOSE

To assess the role of hyperbaric oxygen therapy (HBOT) in the management of recurrent pterygium.

METHODS

Thirty-nine eyes with recurrent pterygium were treated with surgical excision and limbal conjunctival autograft, followed by a course of HBOT. Patients were followed for development of recurrence.

RESULTS

Of the 39 eyes, 18 had a known history of exposure to beta radiation or mitomycin C. The mean duration of follow-up in this group was 23.1 months. A single recurrence was noted in this group. For the remaining 21 eyes, the mean duration of follow-up was 19.4 months. No recurrences were recorded in this group. No significant complications from HBOT were recorded.

CONCLUSIONS

The use of HBOT together with excision and limbal conjunctival autograft for recurrent pterygium is associated with a low recurrence rate. Adjuvant HBOT should be considered in the surgical management of recurrent pterygium.

Hyperbaric oxygen therapy for the treatment of radiation-induced macular ischemia

Purpose:

To report a case of radiation-induced macular ischemia where vision and macular perfusion improved after hyperbaric oxygen (HBO) therapy.

Methods:

A 62-year-old male patient developed radiation-induced macular ischemia after he was treated with radiation for brain glioma. The patient presented with best spectacle-corrected visual acuity (BSCVA) acuity of 20/400 in his right eye. Optical coherence tomography (OCT) showed central macular thickness of 468 μm. The patient received focal laser, intravitreal triamcinolone, and HBO therapy.

Results:

The patient’s vision improved from 20/400 to 20/100 after focal laser and intravitreal triamcinolone. His central macular thickness improved from 468 μm to 132 μm. After receiving HBO therapy, his VA improved to 20/50 and fluorescein angiography showed improvement in macular perfusion.

Conclusion:

HBO therapy improves macular perfusion in patients with radiation-induced macular ischemia.