Corneal Patch Graft: A New Approach for Scleral Necrosis Secondary to Plaque Radiotherapy

Surgical Outcome After Treatment of Radiation-Induced Scleral Necrosis in Patients With Uveal Melanoma

PURPOSE

Surgical repair might be required in patients with uveal melanoma (UM) that develop advanced forms of radiation-induced scleral necrosis (RISN). In this monocentric long-term observational study, we aimed at analyzing the treatment outcome after RISN surgery.

METHODS

All consecutive cases with UM who underwent surgical intervention for RISN between 1999 and 2020 were included. Achievement of the tectonic stability and evaluation of incidence and the risk factors for a repetitive patch surgery (RPS) were the main endpoints.

RESULTS

The final analysis included 57 patients (mean age: 58.7 years; 63.2% female patients), where 55 individuals underwent a patch grafting, and 2 cases were treated with conjunctival reconstructive surgery. The mean follow-up time after grafting was 38.5 months (0.03-221.1 months). Tectonic stability was achieved in 56 (98.3%) patients. Scleral graft (38/55, 69.1%) was the most frequent patching material, followed by Tutopatch (7/55, 12.7%), corneal graft (7/55, 12.7%), dura graft (2/55, 3.6%), and fascia lata (FL) graft (1/55, 1.8%). Eleven patients (20%) underwent RPS after the mean time of 12.9 months (0.3-50.3 months). In the final multivariate Cox regression analysis, the use of Tutopatch (5/7; 71.4%, adjusted hazard ratio = 4.66, P = 0.044) and RISN progression after patch grafting (9/11; 81.8%, adjusted hazard ratio = 9.67, P = 0.008) were independent risk factors for RPS.

CONCLUSIONS

RISN surgery maintains long-term tectonic stability in most of the cases underwent surgical repair for RISN after brachytherapy for UM. Depending on graft material and, particularly, further RISN progression, an RPS might be necessary in certain cases.

Scleral Grafts in Ophthalmic Surgery. A Review

AIM

To summarize the history and current trends in the use of scleral grafts in ophthalmology.

MATERIALS AND METHODS

We conducted a review of the literature through the MEDLINE and Cochrane Library databases. The search terms were "sclera", "graft", and "surgery". The search resulted in 1596 articles, of which we evaluated 192 as relevant. The relevant articles were sorted chronologically and according to the method of using scleral grafts, which enabled the development of a review article.

RESULTS

The sclera has been routinely used in ophthalmology since the 1950s in many different indications. Some of these indications have become practically obsolete over time (for example, use in the surgical management of retinal detachment), but a large number still find application today (especially use in glaucoma or oculoplastic surgery, or as a patch for a defect in the sclera or cornea).

CONCLUSION

Even though allogeneic sclera is currently used less frequently in ophthalmology compared to other tissue banking products and the range of its indications has partially narrowed, it remains a useful material due to its availability and properties.

Extending the utility of anterior corneal buttons through refrigeration and glycerol cryopreservation: utility rate and outcome analysis

BACKGROUND/AIMS

To evaluate the utility rate, indication, outcome, and cost of refrigeration and glycerol cryopreservation for storing anterior corneal buttons during endothelial keratoplasty for subsequent use in tectonic lamellar patch grafting.

METHOD

Anterior corneal buttons collected after precutting or prestripping during endothelial keratoplasty from January 2014 to December 2019 were preserved using the following protocol: (1) refrigeration for up to 4 weeks at 4°C in Optisol-GS and (2) glycerol cryopreservation for up to 2 years. The utility rate, outcome and cost of these cryopreserved anterior corneal buttons were retrospectively examined.

RESULTS

During the 6-year study period, 26 anterior corneal buttons were refrigerated and 49 were cryopreserved for extended use. The utility rates for the refrigerated and cryopreserved anterior corneal buttons were 69.2% and 73.5%, respectively. Their average preservation periods were 0.53±0.05 and 12.76±0.94 months, respectively. Noninfection-related perforation was the leading indication for using the extendedly preserved anterior corneal buttons. The average postoperative follow-up periods were 10.03±2.91 and 14.35±2.17 months for refrigerated and cryopreserved anterior corneal buttons. Secondary keratoplasty was required by 7 of 18 (38.9%) and 6 of 36 (16.7%) patients receiving refrigerated and cryopreserved anterior corneal buttons, respectively. None of our patients developed graft infection from donor tissues.

CONCLUSION

Cryopreservation can safely extend the utility of anterior corneal buttons. This method not only reduced the wastage of the limited donor tissue but also was cost-effective.

Scleral thinning causes, diagnosis, and management: A narrative review

INTRODUCTION

Sclera forms the outer fibrous coat of the eye and provides structural integrity for the housing of intraocular contents. Scleral thinning is a serious progressive condition which can lead to perforation and worsening visual functioning. This review aims to summarize the anatomical consideration and causes of scleral thinning, diagnosis, and the various surgical approaches available to treat scleral thinning.

MATERIALS AND METHODS

The narrative literature review was conducted by senior Ophthalmologists and researchers. PubMed, EMBASE, Web of Science, Scopus, and Google Scholar databases were searched for relevant literature from infinity till March 2022. Terms of the search referred to 'sclera' or 'scleral thinning' or 'scleral melting', and were combined with 'treatment', or 'management' or 'causes'. Publications were included in this manuscript if they offered information about the nature of these topics. Reference lists of relevant literature was searched. There were no limits on type of article to be included for this review.

RESULTS

Scleral thinning arises from diverse congenital, degenerative, immunological, infectious, post-surgical, and traumatic etiologies. It is diagnosed upon slit-lamp examination, indirect ophthalmoscopy, and optical coherence tomography. Conservative pharmacological treatment of scleral thinning may include anti-inflammatory drugs, steroid drops, immunosuppressors, monoclonal antibodies, and surgical treatments including tarsorrhaphy, scleral transplantation, amniotic membrane transplantation, donor corneal graft, conjunctival flaps, tenon's membrane flap, pericardial graft, dermis graft, cadaveric dura mater graft, and other autologous and biological grafts.

CONCLUSION

Scleral thinning treatments have developed dramatically in recent decades and the rise of alternative grafts for scleral transplantation procedures or use of conjunctival flaps have taken center stage in surgical management. This review adds a comprehensive summary of the scleral thinning with attention to the positive and negative features of new treatments alongside previous mainstay management strategies.

Novel technique for late scleromalacia in a ciliary body melanoma due to brachytherapy

INTRODUCTION

We describe a technique using an sclerocorneal endograft sewed through the cornea to solve late scleromalacia following exoresection and brachytherapy of a ciliary body melanoma.

METHODS

Vitrectomy ports were placed. A perforating 400-micron trepan keratoplasty of the cornea was performed allowing the prepared donor graft to be inserted and sutured in place. Intravitreal Perfluorocarbon liquid (PFCL) was used to stabilize the pressure throughout and maintain the graft in place. Once sutured in place, the PFCL was removed and 5000cs of silicone oil introduced. An amniotic membrane was placed surrounding the scleromalacia. The cornea was closed with running sutures.

RESULTS

At one month, the anterior segment optical coherence tomography showed successful endograft placement with no aqueous humor leakage nor hypotony. Currently, the conjunctiva is becoming slightly thicker due to light inflammation, and the eye has recovered the whiteness at the scleromalacia.

CONCLUSIONS

This internal graft technique provides advantages when dealing with poorly healing radiated tissue and reduces the risk of post-operative aqueous humor leakage. Surgeons may consider this approach in cases with a high risk of poor healing or complications resulting from lack of tissue.

Ruthenium-106 plaque radiotherapy for uveal melanoma: analysis of tumor dimension and location on anatomical and functional results

Background

To report the long-term outcomes of Ru-106 plaque radiotherapy in eyes with uveal melanoma (UM) and to assess the effect of tumor thickness and location on final outcomes.

Methods

Medical records of 234 patients undergoing Ru-106 plaque radiotherapy for UM were reviewed, and the visual outcome, globe preservation, and patient survival were evaluated. The results of 2 groups were compared: 1. between thin (small and medium-sized, thickness < 7 mm, 148 eyes [63.2%]) and thick (thickness ≥ 7 mm, 86 eyes [36.8%]) tumors, and 2. between large (largest basal diameter [LBD] > 12 mm, 109 eyes [46.6%]) and medium/small (LBD ≤ 12 mm, 125 eyes [53.4%]). In addition, a comparison of the juxtapapillary location in 46 eyes (19.7%) versus tumors arising elsewhere and between tumors with and without ciliary involvement in 48 eyes (21.5%) were done.

Results

The patients were followed for a median of 54.2 months (range: 6–194.5 months). After adjusting for baseline visual acuity (VA), there was no significant association between final VA and different dimension and tumor location groups. Final globe preservation was 91.9%, and there was no significant difference between different dimension- and ciliary body involvement groups regarding anatomical success rate. The juxtapapillary tumors had lower globe preservation (80.4% vs .94.7%, p = 0.002). The hazard ratio (HR) for enucleation in juxtapapillary tumors was HR = 6.58 (95-CI: 3.84 to 11.21). The overall metastasis rate was 6.8%, with no significant difference in juxtapapillary tumors (4.3% vs.7.4%, p = 0.455).

Conclusions

Ru-106 plaque radiotherapy is an effective treatment for thick and large UM. With this type of treatment, the globe preservation rate is lower in juxtapapillary tumors, but there is no significant difference in the metastasis rate.

Preserved corneal lamellar transplantation for infectious and noninfectious scleral defects: Three case reports and literature review

RATIONALE

: Reinforcement of thinned or necrotizing sclera has been conducted using various materials, including allogeneic sclera, allogenic cornea, amniotic membrane, fascia lata, pericardium, periosteum, and perichondrium. Among them, good outcomes have traditionally been obtained using preserved scleral grafts. However, scleral patch grafts have complications such as graft retraction, thinning, dehiscence, and necrosis. Furthermore, to promote epithelial healing, scleral patch grafting must be accompanied by procedures such as amniotic membrane transplantation (AMT) or grafting using conjunctival flaps or autografts. Recently, acellular preserved human corneas have been used in various ophthalmic surgeries, with emerging evidence supporting its use for treating scleral defects as an option that does not require AMT or conjunctival autografting. We investigated whether corneal patch grafting would show wound healing and tectonic success rate outcomes comparable to those of existing techniques.

PATIENT PRESENTATION

: Three patients presented with intractable ocular pain. Slit-lamp examination showed marked scleral thinning at the nasal side.

DIAGNOSIS

: Scleral thinning progressed with conservative treatment; microbial staining and culturing were performed. Infectious or non-infectious scleritis was diagnosed according to slit-lamp examination and microbial culture results.

INTERVENTIONS

: A preserved corneal lamellar patch was grafted at the scleral thinning area.

OUTCOMES

All patients achieved tectonic success with reduction of inflammation following corneal patch grafting. Two patients achieved complete re-epithelialization within 7 days, while 25 days were required for the third patient. No patients experienced graft thinning, rejection, or infection.

LESSONS

: Our report suggests the feasibility of using acellular preserved human cornea patch grafts to reinforce inflammatory scleral defects and obtain successful outcomes in terms of wound healing. This technique shows a comparable tectonic success rate and superior effect on scleral defect healing without the need for adjunctive AMT or conjunctival autografting.

Preserved Corneal Lamellar Grafting Reduces Inflammation and Promotes Wound Healing in a Scleral Defect Rabbit Model

Purpose

To investigate the effect of preserved corneal lamellar grafting on inflammation and wound healing and to compare its effect with that of preserved scleral grafting in a scleral defect rabbit model.

Methods

New Zealand White rabbits were assigned to a corneal lamellar grafting group (n = 5) or a scleral grafting group (n = 5). After lamellar dissection of superotemporal sclera using 6.0-mm trephine, the same sizes of preserved human corneal or scleral grafts were transplanted with 10-0 nylon interrupted sutures. The grafted areas were photodocumented at 3 to 21 days after surgery to evaluate epithelial wound healing index (%), neovascularization and presence of filaments. The existence of CD3⁺ T cells and CD34⁺ cells at the grafted areas was analyzed at 21 days.

Results

Epithelial wound healing index was significantly higher in the corneal grafting group at 9 days (P < 0.05). Scleral grafts showed copious formation of filaments adherent to the engrafted area from 9 to 14 days, whereas the corneal grafts were free of filaments. The numbers of inflammatory cells were significantly higher in the scleral grafts (P < 0.05), and CD3⁺ T cells and CD34⁺ cells were populated within inflammatory cells at graft-recipient junctions in both groups. The mean areas of the estimated perigraft and intragraft neovascularization tended to be higher in scleral grafts.

Conclusions

Preserved corneal lamellar grafting enhances epithelial wound healing and alleviates inflammation in a scleral defect rabbit model.

Translational Relevance

This work suggests that the preserved corneal graft may be considered as a favorable alternative option for repairing scleral defects.