The use of donor scleral patch in ophthalmic surgery

The Evolving Surgical Paradigm of Scleral Allograft Bio-Tissue Use in Ophthalmic Surgery: Techniques and Clinical Indications for Ab-Externo and Ab-Interno Scleral Reinforcement

To review the latest surgical advances and evolving clinical use of scleral bio-tissue for reinforcement in the eye and review the published literature on novel surgical applications of scleral allograft bio-tissue. Conventional surgical procedures for scleral reinforcement using homologous scleral allograft have been traditionally ab-externo interventions comprising of anterior or posterior reinforcement of the sclera for clinical indications such as trauma, scleromalacia, glaucoma drainage device coverage, scleral perforation, buckle repair as well as posterior reinforcement for pathologic myopia and staphyloma. There have been a few novel ab-interno uses of scleral bio-tissue for reinforcement in both retina and glaucoma. Over the last decade, there has been an increase in peer-reviewed publications on scleral reinforcement, reflecting more interest in its clinical applications. With favorable biological and biomechanical properties, scleral allograft may be an ideal substrate for an array of new applications and surgical uses.

Novel use of an autologous scleral button graft to close the anterior defect in evisceration surgery

PURPOSE

To present an alternative evisceration technique with long-term follow-up data. This technique involves the insertion of an acrylic implant into a modified scleral shell which is closed using an autologous scleral graft.

METHODS

This was a retrospective analysis of eviscerations performed in a district-general hospital in the UK. All patients underwent conventional ocular evisceration after total keratectomy. A full thickness scleral graft is harvested from the posterior sclera, using an internal approach, with an 8 mm dermatological punch. An 18-20 mm acrylic implant is placed into the shell, and the scleral graft is used to close the anterior defect. Demographic characteristics, implant size and type, and cosmetic results from pictures of all patients were recorded. All patients were invited for a review to measure motility, eyelid height, patient recorded satisfaction and complications.

RESULTS

Of the five patients identified, one had since died. The remaining four attended a review in person. The mean time between surgery and review was 48 months. The mean implant size was 19 mm. There were no cases of implant extrusion or infection. All four had a <1 mm asymmetry in measured eyelid height and ≥5 mm horizontal gaze motility. All patients self-reported "good" cosmesis. An independent assessment identified "mild asymmetry" in two cases and "moderate" in the other two.

CONCLUSION

Evisceration with this novel autologous scleral graft technique restores volume in the anterior orbit with good cosmetic results, and with no cases of implant exposure reported in this small case series. This technique should be compared prospectively to established techniques.

Giant anterior scleral staphyloma caused by blunt ocular trauma: a case report

BACKGROUND

Anterior scleral staphyloma is a relatively rare disease characterized by thinning and expansion of sclera. We described the clinical presentation, diagnosis and treatment of a case with giant anterior scleral staphyloma caused by blunt ocular trauma.

CASE PRESENTATION

A 24-years-old male, presented with a black cyst-like mass protruding from the right eyeball for 9 years after a history of glass crush contusion. The ultrasound biomicroscopy examination showed two cysts in the right eyeball. The larger one was about 5.92 mm*4.69 mm in size and the scleral lacerations were connected to the posterior chamber below the cyst. For treatment, resection of the anterior scleral staphyloma and the scleral patch graft transplantation was performed. The vision of the patient was improved compared with that before surgery. There were no obvious complications.

CONCLUSION

The clinical presentation, diagnosis, and treatment of the case with giant anterior scleral staphyloma can provide a reference for the management of anterior scleral staphyloma. Surgical resection and scleral patch graft should be a good option for the treatment of giant anterior scleral staphyloma.

Anterior staphyloma repair following trauma and surgery - A retrospective review of techniques and outcomes over 25 years

Purpose

To review surgical options, techniques, and outcomes of anterior staphyloma repair done following trauma and surgery.

Methods

This was a retrospective case study of patients who underwent staphyloma repair with scleral or tibial periosteal patch grafts following trauma and surgery with a minimum follow-up of 3 months postoperatively. Preoperative risk factors, choice of graft materials, surgical details, and outcomes in terms of graft uptake and tectonic integrity were analyzed.

Results

Seventeen eyes of 17 patients underwent successful staphyloma repair (scleral 15, tibial periosteal two). Mean follow-up was 47.1 months (3-159 months). Postoperative intraocular pressure rise noted in four eyes was controlled medically or surgically. Three patients underwent successful repeat patch grafting (graft melt one and recurrent ectasia two). Tectonic integrity of the eyeball was restored and maintained in all patients at the final follow-up.

Conclusion

Comprehensive evaluation of the risk factors, control of ocular comorbid conditions, and early and meticulous surgery can optimize results.

Case series of scleral patch grafts during COVID-19 pandemic

Scleral graft is done for clinical conditions as scleral melt post pterygium surgery, immune or infection related scleral melt, for covering the tubes of Ahmed glaucoma valve implant, for covering the orbital implants post enucleation, etc. A review of literature revealed the use of sclera for corneal perforations in the past, but became obsolete after the cornea being used for patch grafts. Now in this COVID-19 time, due to scarcity of corneal tissue, this technique of scleral patch grafts can be considered as an alternative to corneal patch grafts, which serves well the tectonic/therapeutic purpose and helps salvage the eye.

The usability of lamellar scleral autograft in ocular perforation treatment

IMPORTANCE

Open globe injury is a frequent and preventable healthcare problem with an annual incidence of 3.5/100,000 worldwide. Management and treatment methods aim to ensure globe integrity. Unfortunately, it is not possible to achieve globe integrity in some of the cases, and these can result in poor visual outcomes.

PURPOSE

To evaluate the usability of lamellar scleral graft in the repair of ocular perforations.

METHODS

This was a retrospective review of 11 patients who underwent lamellar scleral graft surgery for ocular perforation between June 2015 and June 2020. Due to the failure of the repairs when other techniques were used, the perforation zones were sealed with lamellar scleral autografts. The primary measures of the outcomes were globe integrity, postoperative best corrected visual acuity, and intraocular pressure (IOP). Visual acuity was determined using the Snellen eye chart, and IOP was measured using the automated pneumatic tonometry during standard examination.

RESULTS

The participants enrolled in this study included 11 patients who underwent lamellar scleral patch graft between 2015 and 2020. The mean age of the patients was 58.81 ± 16.6 years (range, 16-77), and the mean follow-up period was 12.5 ± 3.8 months (range, 8-20). During the surgery, the perforation zone was treated and no leakage was observed. IOP significantly increased, and visual acuity improved in almost all eyes. The factors that made it necessary to use scleral grafts in patients were star-shaped wounds, delayed presentation, lost corneal / scleral tissue.

CONCLUSION

Lamellar scleral graft is a method that can be used in the treatment of defective ocular perforation with acceptable complications and provides adequate functional and structural stability. Scleral patch grafting can be considered as an alternative option for surgeons treating a variety of ocular conditions that cause tectonic imbalance or poor cosmesis.

Current clinical application of sclera and amniotic membrane for ocular tissue bio-replacement

To report the current clinical applications and trends of scleral and amniotic membrane use in ophthalmology. Review of annual reports from the Catalan Transplant Organization (OCATT), on scleral patch and amniotic membrane eye indications in Catalonia region (Spain) over a 6-year period from 2013 to 2018. A total of 874 scleral and 1665 amniotic membranes patches were implanted, from January 2013 to December 2018. The most frequent indication over the 6-year period for scleral patch was glaucoma surgery (77.5%), eyelid reconstruction (5.2%) and corneal or scleral ulcer (5%). Regarding amniotic membrane, corneal ulcer (26.9%), conjunctival reconstruction (23.8%) and corneal epithelial defect (22.7%) were the most common indications. During the study period, an increasing trend was found on sclera patches for eyelid reconstruction (p = 0.0032) and amniotic membrane for inflammation management (p = 0.0198). Glaucoma surgery and corneal ulcers have represented the top indications for scleral patch and amniotic membrane use, over the period, respectively. A significant trend has also been found towards eyelid reconstruction using scleral patches and amniotic membrane for anterior segment inflammation management. This evolving scenario in tissue use for ocular surgery has to be taken into consideration, especially regarding eye banks facing current and futures changes in tissue preservation, storage and indications.

Surgical and Immunohistochemical Outcomes of Scleral Reconstruction with Autogenic, Allogenic and Xenogenic Grafts: An Experimental Rabbit Model

Purpose: Choukroun's platelet-rich fibrin (PRF), a second-generation platelet concentrate, has unique morphological and chemical features and may be considered as a scaffold for scleral reinforcement and regeneration. The purpose of this study was to compare the use of xenogenic human-derived amniotic membrane (HAM), allogenic sclera, and autogenic PRF in rabbit lamellar scleral defect model with respect to both anatomical and immunohistochemical improvement. Methods: A total of 45 adult New Zealand rabbits were randomized into five groups: normal control; without surgical procedure, negative control; scleral defect model (SDM), xenogenic HAM; SDM+HAM graft, allogenic sclera; SDM+allogenic sclera graft, autogenic PRF; SDM+autogenic PRF graft. Clinical findings, Hematoxylin&Eozin (HE), Masson Trichrome, Verhoeff Acid Fuchsin, Transforming Growth Factor β Receptor 1, Fibroblast Growth Factor, Bone Morphogenetic Protein 2, collagen type 1, aggrecan, and Matrix Metalloproteinase 2 were evaluated. Results: Ocular surface inflammation was significantly lower in normal control and autogenic PRF groups (p < .001). Graft was avascular and not integrated to scleral wound area in 25% rabbits of allogenic sclera group (p = .02), was out of the scleral wound in 33.3% rabbits of xenogenic HAM group (p > .05), all the grafts were at the normal location and viable in autogenic PRF group. The inflammation and vascularization in autogenic PRF group was significantly lower than negative control and xenogenic HAM groups in HE (p < .001). The collagen score of negative control and xenogenic HAM groups were significantly lower than normal control (p < .001) and autogenic PRF (p < .001) groups. There were insignificant differences between allogenic sclera and autogenic PRF groups (p > .05). For immunohistochemistry, the closest values to normal control group were detected in autogenic PRF group for all immunomarkers. Conclusion: Autogenic PRF showed superior features via its excellent anatomical and chemical composition for scleral regeneration when compared to single-layered xenogenic HAM and allogenic sclera grafts.

Oral mucosa for reconstructive surgery in a case of severe inflammatory necrotizing sclero-uveitis

The purpose of this case is to show the efficacy of buccal mucosa as an alternative to treat a case of severe necrotizing sclero-uveitis (NSU) associated with ocular perforation. We show a severe inflammatory NSU case that did not improve with topical treatment and scleral patch. We performed a buccal mucosa graft taken from the lower lip with excellent functional and anatomical result, with no signs of relapse of the NSU after 2 years of follow-up. Buccal mucosa can be a safe, useful, and effective alternative for the reconstruction of the scleral wall.

RD repair using 360-degree scleral graft for extensive scleral ectasia in a patient with Ehlers Danlos syndrome

Purpose

To report a case of a woman who had Ehlers Danlos syndrome who developed a bullous retinal detachment.

Observations

A 33-year-old Caucasian woman presented with 1-day history of floaters and photopsia. Patient had extensive scleral ectasia. Scleral buckle could not be performed due the severity of the ectasia. Patient had a vitrectomy and subsequently had multiple re-detachments with sclera ruptures during the retinal detachment repairs. Patient required a 360-degree scleral patch graft to prevent scleral ruptures during the vitrectomy. Patient has a stable flat report 7 months post-op with vision of 1/60.

Conclusions and importance

This is the first case report of a patient requiring a 360-degree scleral patch graft. This option should be considered to assist in preventing scleral ruptures, intraoperatively and post operatively in patient who have an increased risk of scleral rupture, such as patients with connective tissue disorders.

Scleral surgical repair through the use of nanostructured fibrin/agarose-based films in rabbits

Scleral defects can result as a consequence of trauma, infectious diseases or cancer and surgical repair with allogeneic scleral grafts can be required. However, this method has limitations and novel alternatives are needed. Here, the efficacy of acellular nanostructured fibrin-agarose hydrogel-based substitutes (NFAH) in the repair of scleral defects in rabbits was studied. For this, scleral defects of 5-mm diameter were made on 18 adult-male New Zealand rabbits and repaired with acellular NFAH, NFAH crosslinked with genipin (NFAH-GP) or glutaraldehyde (NFAH-GA), allogeneic scleral grafts as control (C-CTR) or not repaired (negative control N-CTR) (n = 3 each). Macroscopic and histological analyses were performed after 40-days. Macroscopy confirmed the repair of all defects in a comparable manner than the C-CTR. Histology showed no degradation nor integration in C-CTR while NFAH-GP and NFAH-GA biomaterials were encapsulated by connective and inflammatory tissues with partial biodegradation. The NFAH were fully biodegraded and replaced by a loose connective tissue and sclera covering the defects. This in vivo study demonstrated that the NFAH are a promising biocompatible and pro-regenerative alternative to the use of allogeneic cadaveric grafts. However, large defects and long-term studies are needed to demonstrate the potential clinical usefulness of these substitutes.

Catastrophic Thermal Corneoscleral Injury Treated with Transplantation of Donor Scleral Graft

BACKGROUND

The aim of this study is to report a patient with senile cataract developing severe thermal corneoscleral injury during phacoemulsification, which was treated with a donor scleral graft.

CASE

Severe thermal corneoscleral injury occurred during phacoemulsification in the right eye of a 74-year-old male. His medical history was prostate hypertrophy. Visual acuity was hand motion and the intraocular pressure was 3 mm Hg OD. There was heavy corneal stromal opacity with intraocular fluid leakage. The patient underwent transplantation of a donor scleral graft to the burn site. Histologically, the injured sclera showed coagulation necrosis without inflammatory cell infiltration. An intraocular lens was eventually fixed in the ciliary sulcus 7 months later. His visual acuity remains at 2/20 OD.

CONCLUSIONS

Transplantation of the donor scleral grafts is useful to close the wound in catastrophic thermal injury.