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

Emerging Indications for Hyperbaric Oxygen Treatment: Registry Cohort Study

BACKGROUND

Hyperbaric oxygen (HBO2) treatment is used across a range of medical specialties for a variety of applications, particularly where hypoxia and inflammation are important contributors. Because of its hypoxia-relieving and anti-inflammatory effects HBO2 may be useful for new indications not currently approved by the Undersea and Hyperbaric Medical Society. Identifying these new applications for HBO2 is difficult because individual centers may only treat a few cases and not track the outcomes consistently. The web-based International Multicenter Registry for Hyperbaric Oxygen Therapy captures prospective outcome data for patients treated with HBO2 therapy. These data can then be used to identify new potential applications for HBO2, which has relevance for a range of medical specialties.

OBJECTIVE

Although hyperbaric medicine has established indications, new ones continue to emerge. One objective of this registry study was to identify cases where HBO2 has been used for conditions falling outside of current Undersea and Hyperbaric Medical Society-approved indications and present outcome data for them.

METHODS

This descriptive study used data from a web-based, multicenter, international registry of patients treated with HBO2. Participating centers agree to collect data on all patients treated using standard outcome measures, and individual centers send deidentified data to the central registry. HBO2 treatment programs in the United States, the United Kingdom, and Australia participate. Demographic, outcome, complication, and treatment data, including pre- and posttreatment quality of life questionnaires (EQ-5D-5L) were collected for individuals referred for HBO2 treatment.

RESULTS

Out of 9726 patient entries, 378 (3.89%) individuals were treated for 45 emerging indications. Post-COVID-19 condition (PCC; also known as postacute sequelae of COVID-19; 149/378, 39.4%), ulcerative colitis (47/378, 12.4%), and Crohn disease (40/378, 10.6%) accounted for 62.4% (n=236) of the total cases. Calciphylaxis (20/378, 5.3%), frostbite (18/378, 4.8%), and peripheral vascular disease-related wounds (12/378, 3.2%) accounted for a further 13.2% (n=50). Patients with PCC reported significant improvement on the Neurobehavioral Symptom Inventory (NSI score: pretreatment=30.6; posttreatment=14.4; P<.001). Patients with Crohn disease reported significantly improved quality of life (EQ-5D score: pretreatment=53.8; posttreatment=68.8), and 5 (13%) reported closing a fistula. Patients with ulcerative colitis and complete pre- and post-HBO2 data reported improved quality of life and lower scores on a bowel questionnaire examining frequency, blood, pain, and urgency. A subset of patients with calciphylaxis and arterial ulcers also reported improvement.

CONCLUSIONS

HBO2 is being used for a wide range of possible applications across various medical specialties for its hypoxia-relieving and anti-inflammatory effects. Results show statistically significant improvements in patient-reported outcomes for inflammatory bowel disease and PCC. HBO2 is also being used for frostbite, pyoderma gangrenosum, pterygium, hypospadias repair, and facial filler procedures. Other indications show evidence for improvement, and the case series for all indications is growing in the registry.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/18857.

Modified Limbal-Conjunctival Autograft Surgical Technique: Long-Term Results of Recurrence and Complications

PURPOSE

The aim of this study was to report the recurrence and complication rates of a modified limbal-conjunctival autograft surgical technique for pterygium excision.

METHODS

This was a retrospective, single-surgeon, single-operating environment, consecutive case series of 176 eyes in 163 patients with a biopsy-proven diagnosis of pterygium. All patients underwent excision using a 23-gauge needle to "behead" the pterygium head, followed by a limbal-conjunctival autograft including ∼50% of the palisades of Vogt. Outcomes measured included recurrence, defined as any conjunctival fibrovascular growth, and complication rates. Correlations between preoperative patient characteristics, pterygium morphology, and intraoperative factors (width of corneal extension, conjunctival defect, and graft) with postoperative recurrence were examined using logistic regression models.

RESULTS

The median age was 59.5 years and 122 eyes (69.3%) had primary pterygium (type I: 17%, II: 37.5%, and III: 45.5%). Kaplan-Meier analysis demonstrated the median pterygium-free follow-up period to be 723 days (range 46-7230 days). Recurrence was observed in 3 eyes of 2 patients (1.7%). No postoperative graft-related complications were observed. Postoperative symptomatology was transient. Age demonstrated a negative correlation with recurrence (odds ratio 0.888, 95% CI, 0.789-0.998, P = 0.046). However, no other correlations with preoperative or intraoperative factors, including whether pterygium was primary or recurrent, were identified (all P > 0.05).

CONCLUSIONS

This modified limbal-conjunctival autograft technique represents an effective alternative that offers a very low recurrence rate and avoids extensive dissection or antimetabolites, with minimal complications and transient postoperative symptomatology, over a long-term follow-up period. This technique is relatively simple and successful for both primary and recurrent pterygia. Future comparative studies with other surgical techniques may determine which are superior.

Oxygen-Carrying Capacity of Perfluorohexyloctane, a Novel Eye Drop for Dry Eye Disease

Objective

One-hundred percent perfluorohexyloctane (PFHO) is a water-free, preservative-free eye drop approved by the Food and Drug Administration in the United States for the treatment of dry eye disease. PFHO has shown relief of dry eye signs and symptoms in clinical trials and has potent antievaporative action in vitro. The objective of this study was to measure the level of oxygen in PFHO.

Methods

T1 relaxation times (time taken for proton spins to translate from a random alignment to an alignment with the main magnetic field) for fluorine-19 in perfluorohexyloctane were measured using fluorine-19 nuclear magnetic resonance spectroscopy. The level of oxygen was interpolated from published data.

Results

The hydrogen-1 and fluorine-19 nuclear magnetic resonance spectra of PFHO were well resolved and the resonance assignments and intensities were as expected. The T1 values calculated for the CF₃ group resonance in the current study was 0.901 seconds and 1.12 seconds at 25 °C and 37 °C, respectively. The T1 values for the CF₂ group resonances increased by 17% to 24% with an increase in temperature from 25 °C to 37 °C. The mean (SD) partial pressure of oxygen in PFHO was calculated to be 257 (36) mm Hg and 270 (38) mm Hg at 25 °C and 37 °C, respectively.

Conclusions

The current study confirms that PFHO contains a significant amount of oxygen, more so than that calculated for tears in equilibrium with air. Once instilled on the eye, PFHO is not expected to be a barrier to the oxygen necessary for a healthy cornea and may in fact deliver nonreactive oxygen to the cornea to facilitate healing in patients with dry eye disease.

[Transplantation of the Bowman's layer in combined treatment of recurrent pterygium]

Pterygium is among the most frequent indications for extraocular ophthalmic surgery. The main method of pterygium treatment - its excision - is often combined with transplantation, non-transplantation, medication and other methods. However, the frequency of pterygium recurrence can exceed 35%, and the cosmetic and refraction outcomes satisfy neither the patient, nor the surgeon.

PURPOSE

The study analyses the technical capability and feasibility for transplantation of the Bowman's layer in the treatment of recurrent pterygium.

MATERIAL AND METHODS

The transplantation of the Bowmen's layer was performed according to the developed technique on 7 eyes with recurrent pterygium (7 patients aged 34 to 63 years). The combined surgery technique consisted of pterygium resection, laser ablation, autoconjunctival plasty, exposure to a cytostatic drug, non-suture transplantation of the Bowman's layer. Maximum length of the follow-up was 36 months. Analysis involved data from refractometry, visometry (without correction and with spectacle correction), and optical coherence tomography of the retina.

RESULTS

There were no complications in any of the studied cases. The cornea and the transplant retained transparency throughout the entire follow-up duration. 36 months after surgery mean spectacle-corrected visual acuity amounted to 0.86±0.2, topographic astigmatism - 1.48±1.4 diopters. Recurrence of pterygium was not observed. All patients were satisfied with the cosmetic outcomes of the treatment.

CONCLUSION

Non-suture transplantation of the Bowmen's layer recovers normal anatomy, physiology and transparency of the cornea after repeat surgical intervention for pterygium. No pterygium recurrences were observed throughout the entire follow-up after treatment with the proposed combined technique.

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.

Effects of excimer laser phototherapeutic keratectomy in limbal-conjunctival autograft transplantation for recurrent pterygium: a retrospective case control study

BACKGROUND

Repeated surgery excisions could induce obvious irregular astigmatism in patients with recurrent pterygium. Our study is aimed to illustrate the effect of adjunct excimer laser phototherapeutic keratectomy (PTK) in limbal-conjunctival autograft transplantation on visual quality for patients with recurrent pterygium.

METHODS

Retrospective case-control study. Eyes that underwent pterygium excision with (PTK group) or without (control group) PTK from 2006 to 2017 were retrospectively included. Recurrence rate, preoperative and postoperative surface regularity index (SRI), surface asymmetry index (SAI), cylinder and LogMAR vision were collected. Postoperative anterior segment optical coherence topography and in vivo confocal microscopy were performed to monitor the cornea epithelium healing and cellular recovery process respectively.

RESULTS

A total of 99 eyes of 99 patients were collected, of which 39 were treated with PTK and 60 without PTK. The mean follow-up time was 50.4 ± 38.1 months. The recurrence rate was 10.3% (4 eyes) in the PTK group and 13.3% (8 eyes) in the control group (p = 0.759). The SRI decreased 0.53 (range: - 0.88, 2.81), SAI decreased 0.53 (range: - 0.64, 2.94), and the cylinder decreased 2.08 (range:-0.16, 9.40) D in the PTK group, and the corresponding values were 0.48 (range:-0.45, 2.27), 0.27 (range:-1.06, 2.21) and 0.71 (range:-1.75, 3.55) D in the control group, respectively (Z = 1.76, 2.15, and 3.97, p = 0.005, 0.016, and 0.000 respectively). LogMAR vision improved in both groups after surgery, with an improvement of 0.18 (range: 0.00, 0.70) in the PTK group and 0.06 (range: - 0.12, 0.50) in the control group (Z = 4.08, p = 0.000). Besides, the eyes treated with PTK showed faster re-epithelization and better cellular recovery.

CONCLUSIONS

For recurrent pterygium, surgical excision with adjunct PTK might be a better option with improved corneal surface and vision outcomes.

Paradigm shifts, peregrinations and pixies in ophthalmology

Human ingenuity is challenged by defending vision, our highest bandwidth sense. Special challenges are presented by the replacement or repair of highly specialized but scarce tissue within the constraints of transparency, tissue shape and alignment, tissue borders and pressure maintenance. Many, mostly destructive, surgical procedures were developed prior to an understanding of underlying pathophysiology. For a number of conditions, both reconstructive and destructive procedures co-exist, yet there are few guidelines as to the better approach. Because the consequences of these procedures may take many years to surface (consistent with a stem cell role in long-term tissue maintenance), guidance may be provided by the elucidation of underlying principles from these approaches. Illustrative examples from clinical, basic research and biotechnology, particularly relating to pterygium, ocular surface squamous neoplasia, dry-eye syndrome, corneal rehabilitation and replacement, cataract surgery, strabismus surgery and bionic eye research, are described. An unexpected consequence of bionic device development has been an appreciation of the sophistication of tissues being replaced, given the limitations of available biomaterials. Examples of how this has provided insights into ocular disease will be illustrated. Stem cell and biomaterial technologies are starting to impact at a time when cost-effectiveness is under scrutiny. Both efficacy and cost will need to be considered as these interventions are introduced. It appears that the paradigm shift rate is accelerating and there is evidence of this in ophthalmology. Lessons learned from the areas of destructive versus reconstructive surgery and the limitations of development of bionic replacements will be used to illustrate how new procedures and technologies can be developed.

Management of complicated multirecurrent pterygia using multimicroporous expanded polytetrafluoroethylene

Aims

To evaluate the efficiency of multimicroporous expanded polytetrafluoroethylene (e-PTFE) insertion in complicated multirecurrent pterygia.

Methods

A total of 62 eyes from 62 patients with a multirecurrent pterygium associated with symblepharon or motility restriction-related binocular diplopia were recruited. All eyes underwent pterygia excision followed by application of 0.033% mitomycin C, amniotic membrane transplantation and conjunctival limbal autograft. Multimicroporous e-PTFE was then inserted intraoperatively in 30 eyes between the transplanted amniotic membrane and the conjunctiva (group A), but not inserted in the other 32 eyes (group B). The main outcome measures were symblepharon formation, motility restriction, binocular diplopia, subjective score of conjunctival hyperaemia and postoperative pterygium recurrence.

Results

In the mean follow-up period of 17.2±2.3 months, symblepharon formation, motility restriction, diplopia and conjunctival hyperaemia were significantly improved after surgery in group A patients (p=0.000, 0.000, 0.008 and 0.000, respectively). Postoperative symblepharon formation, motility restriction and conjunctival hyperaemia were significantly less in group A compared to group B (p=0.024, 0.027 and 0.000, respectively). After surgery, corneal recurrence developed in one eye (3.3%) from group A, which was significantly lower than the eight eyes (25%) from group B (p=0.027).

Conclusions

Multimicroporous e-PTFE insertion may provide a novel approach for treating intractable complicated multirecurrent pterygia.