Surgical management of peripheral corneal thinning disorders

Strategies for successful management of moderate and severe Mooren's ulcer at a rural center during the COVID-19 pandemic: Lessons learnt

PURPOSE

This study aimed to report the strategies that evolved in managing Mooren's ulcer (MU) at a resource-limited center in rural India during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

This study includes a retrospective analysis of clinically diagnosed MU cases from January 2021 to August 2021 wherein strategies for management were developed. The demographic profile, ulcer clinical features, treatment algorithms (medical and surgical), complications encountered, referral to a higher center, and compliance with medication and follow-up were studied.

RESULTS

The mean age of presentation was 68.1 years (range, 62-73 years), and 90% were men. The median best-corrected visual acuity (BCVA) was 1.26 logarithm of the Minimum Angle of Resolution (LogMAR) (interquartile range (IQR), 0.00-5 logMAR) in the affected eye on presentation, which improved to 0.69 logMAR (IQR, 0.00-3 logMAR) at resolution ( P = 0.442). The first-line management was conjunctival resection and tissue adhesive application (90%). 70% of cases were unilateral, 50% of cases had less than 2 clock hours of involvement, and 50% had less than 50% stromal involvement. Confounding factors included infectious keratitis (2) and corneal perforation (3). The mean duration of follow-up was 96 (1-240) days. The average follow-up visits per patient were 8.8 (1-22). 90% of cases could be managed successfully at the secondary center level with two cases needing a tertiary care referral.

CONCLUSION

MU can be managed effectively by following a systemic strategy of early diagnosis, surgical therapy, and rapid institution of systemic immunosuppression in a remote location-based secondary center. The strategies developed can be a guide for ophthalmologists at remote centers managing patients or who are unable to travel to tertiary institutes.

Customized therapeutic deep anterior lamellar keratoplasty in perforated Mooren's ulcer: A novel technique

We describe customized therapeutic deep anterior lamellar keratoplasty (DALK) for treating a perforated Mooren's ulcer. Slit-lamp biomicroscopy revealed corneal perforation (3.5 mm × 3.0 mm) with iris prolapse. The corneal melt extended from 9.0 o'clock to 4.0 o'clock. The peripheral edge of the ulcer was sloping, whereas the medial edge showed undermining. Immunological tests did not reveal any evidence of systemic autoimmune disease. In view of extensive peripheral corneal melt with large corneal perforation, the patient needed tectonic keratoplasty. The penetrating graft is not only technically demanding but also results in a poor visual outcome. We advised customized tectonic DALK. We used two different-sized trephines to obtain appropriate-sized donor tissue and avoided manual dissection. The post-surgery period was uneventful. He was prescribed topical steroids and oral methotrexate. He achieved 6/9 aided visual acuity at 4 months and maintained it until the last follow-up at 36 months.

Surgical management of infectious keratitis

The successful management of infectious keratitis is usually achieved with a combination of tools for accurate diagnosis and targeted timely antimicrobial therapy. An armamentarium of surgical interventions is available in the acute stage which can be resorted to in a step wise manner or in combination guided by the response to treatment. Simple surgical modalities can facilitate accurate diagnosis e.g. corneal biopsy and alcohol delamination. Surgery to promote epithelial healing can vary from tarsorrhaphy, amniotic membrane transplantation or conjunctival flaps depending on the extent of infection, visual prognosis, availability of tissue and surgeon's experience. Collagen crosslinking has been increasingly utilized with successful results to strengthen the cornea and reduce the infective load consequently the need for further elaborate surgical interventions. It has shown encouraging results specially in superficial bacterial and fungal keratitis but for deeper infections, viral and acanthamoeba keratitis, its use remains questionable. When globe integrity is compromised, corneal gluing is the most commonly used procedure to seal small perforations. In larger perforations/fulminant infections a tectonic/therapeutic graft is advisable. Partial thickness grafts are increasingly popular to treat superficial infection or internally tamponade perforations. Peripheral therapeutic grafts face challenges with potential requirement for a manually fashioned graft, and increased risk of rejection due to proximity to the limbal vessels. Late stage visual rehabilitation is likely to require further surgical interventions after complete resolution of infection and inflammation. A preliminary assessment of corneal sensation and integrity of the ocular surface are key for any successful surgical intervention to restore vision.

Post-penetrating keratoplasty astigmatism

Postoperative astigmatism is one of the common complications affecting visual outcomes after a penetrating keratoplasty. It can result from various factors related to host, donor and surgical technique, resulting in suboptimal visual outcome. While some of the measures taken during preoperative planning and during actual surgery can reduce the magnitude of postoperative astigmatism, postoperative correction of astigmatism is often required in cases with high degrees of astigmatism. When spectacles and contact lenses fail to provide optimal visual outcomes, various surgical techniques that include astigmatic keratotomy, compression sutures, toric intraocular lens placement, and laser refractive procedures can be considered. When none of these techniques are able to achieve a desired result with in the acceptable optical range, a repeat keratoplasty is considered a last option. We discuss the various causes and management of complication of postoperative astigmatism occurring after a full thickness corneal transplantation surgery.

Anterior Segment Ischemia After Peripheral Annular Lamellar Sclerokeratoplasty for Advanced Terrien Marginal Degeneration

ABSTRACT

A man with 360° bilateral peripheral thinning, peripheral vascularization, and lipid deposition diagnosed with Terrien marginal degeneration, underwent a 360° peripheral annular lamellar sclerokeratoplasty (PALK) (tuck-in) in the right eye for 90% peripheral thinning and high astigmatism. One-week postoperatively, a sudden drop in vision to counting fingers 1 m from 20/50 with circumciliary congestion, diffuse corneal edema, intense anterior chamber inflammation, keratic precipitates with fixed dilated pupil, and hypotony led to a diagnosis of suspected anterior segment ischemia. Anterior segment fluorescein angiography was suggestive of ischemia. After intensive topical and systemic steroids tapered over 6 months, his symptoms and signs improved. At the last follow-up 4 years later, his best contact lens-corrected visual acuity was 20/30. Anterior segment ischemia has not been reported after a PALK for advanced corneal ectatic disorders. Prompt diagnosis and commencement of intensive steroids was helpful in reversing this condition.

Two-step keratoplasty for deep vascularized corneal opacity with severe peripheral thinning following Acanthamoeba keratitis

PURPOSE

In cases of corneal opacity with vascularization and peripheral thinning, traditional keratoplasty techniques have several risks and drawbacks. We report the results of a two-step surgical strategy consisting in performing a large diameter tectonic lamellar keratoplasty (TLK) to restore appropriate corneal thickness and an avascular recipient bed, followed by central optical PK within the lamellar graft at a later date.

METHODS

This single-institution study analyzes the results of 7 eyes of 7 patients who received PK after large diameter TLK. All patients were affected by deep post-infectious corneal opacity with persistent stromal vascularization and peripheral thinning. The main outcomes measured were graft survival, visual acuity, refraction, and endothelial cell density.

RESULTS

TLK was performed in all cases with 10/10.1-mm diameters. After a mean interval of 14 months, central PK was performed with a median host-graft diameter of 7.75/8.25 mm. Mean follow-up after PK was 52 months. At last follow-up, 6/7 (86%) grafts were clear. Endothelial rejection occurred in 5/7 (71%) eyes, with one patient having multiple episodes and subsequent graft failure. At 2 years, all patients had a visual acuity ≥ 20/40, with an average refractive astigmatism of 3.75 diopters.

CONCLUSION

Optical PK within a previous TLK is a safe and efficient technique for treating deep corneal opacity associated with extensive vascularization and peripheral thinning. Extended follow-up period is necessary to assess endothelial cell loss and long-term efficacy of the procedure.

Mini-Descemet Stripping-Automated Endothelial Keratoplasty for Macro Corneal Perforations

PURPOSE

We present a technique that preserves good vision in paracentral macroperforations and avoids challenges of tectonic lamellar or penetrating keratoplasty in eyes with poor visual potential.

METHOD

A wet laboratory was implemented for mini-Descemet stripping endothelial keratoplasty to seal macroperforations ab interno. This included a suture support technique designed to prevent graft herniation. We also present 3 cases who were treated successfully with this technique.

RESULTS

The laboratory test confirmed that mini-Descemet stripping endothelial keratoplasty can successfully seal macroperforations without the need of large incisions. The minidisc is introduced through the perforation, and a double mattress suture prevents graft herniation. The technique allowed us to preserve 20/15 unaided vision in a case with paracentral macroperforation. It also restored eye globe integrity and achieved long-term stability in 2 cases with limbal stem-cell deficiency.

CONCLUSIONS

Mini-Descemet stripping-automated endothelial keratoplasty technique can be an alternative approach to avoid poor visual outcomes of tectonic keratoplasty in paracentral perforations. It also offers host tissue preservation in eyes with high risk of rejection for tectonic grafts.

Low-Concentration (0.66%) Povidone Iodine Treatment of a Corneal Ulcer in a Rheumatoid Arthritis Patient

Patient: Female, 89-year-old

Final Diagnosis: Corneal ulcer

Symptoms: Low vision

Medication:—

Clinical Procedure: —

Specialty: Ophthalmology

Peripheral ulcerative keratitis in rheumatoid arthritis patients taking tocilizumab: paradoxical manifestation or insufficient efficacy?

Objectives

Peripheral ulcerative keratitis (PUK) is a severe corneal condition associated with uncontrolled RA. Tocilizumab (TCZ) is used to control RA, however, episodes of paradoxical ocular inflammation have been reported in TCZ-treated patients. We report a case series of PUK in TCZ-treated RA patients with ophthalmological and systemic findings and discuss the potential underlying mechanisms.

Methods

Four patients (six eyes), 47–62 years of age, were included. At the onset of PUK, the median duration of RA was 13 years [interquartile range (IQR) 3–13] and the median treatment with TCZ was 9 months (IQR 3–14). Two patients had active disease [28-joint DAS (DAS28) >3.2] and the disease was controlled in two patients (DAS28 ≤3.2).

Results

TCZ was initially replaced by another immunomodulatory treatment in all patients and later reintroduced in two patients without PUK recurrence. Corneal inflammation was controlled in all cases with local and systemic treatments, with severe visual loss in one eye.

Conclusion

PUK may occur in patients with long-standing RA after a switch to TCZ and can be interpreted, depending on the context, as insufficient efficacy or a paradoxical manifestation. These cases highlight the urgent need for reliable biomarkers of the efficacy and paradoxical reactions of biologics.

Management of corneal perforations: An update

Corneal perforation is a potentially devastating complication that can result from numerous conditions that precipitate corneal melting. It is associated with significant morbidity and prompt intervention is necessary to prevent further complications. Causes include microbial keratitis, ocular surface disease, and autoimmune disorders and trauma. Various management options have been described in the literature to facilitate visual rehabilitation. This rview discusses the treatment options that range from temporising measures such as corneal gluing through to corneal transplantation, with decision making guided by the location, size, and underlying aetiology of the perforation.

Peripheral Ulcerative Keratitis in a Patient with Bilateral Scleritis: Medical and Surgical Management

Peripheral ulcerative keratitis (PUK) is a group of corneal disorders that cause peripheral corneal thinning, threatening globe integrity in advance stages. It is usually associated with systemic autoimmune diseases and management is based on local and systemic approaches. We present the case of a 47-year-old man with a previous history of bacterial keratitis in his left eye presenting with 1 month of bilateral ocular pain and redness. At examination, diffuse bilateral globe inflammation with paracentral corneal thinning in his left eye was observed. He was diagnosed with bilateral scleritis and PUK in his left eye. Workup for associated systemic autoimmune disease yielded negative results. The patient was started on pulses of intravenous methylprednisolone followed by oral prednisone failing to achieve sufficient control of the inflammatory syndrome. Subsequently, periodic intravenous cyclophosphamide was administered with a favorable response. A multilayer amniotic membrane graft was applied, but there was rapid melting with reabsorption of the tissue, resulting in extreme corneal thinning at the inferior paracentral cornea. A decentered 8.5-mm superficial anterior lamellar keratoplasty (SALK) was then performed obtaining the donor graft with a femtosecond laser but performing manual trepanation in the recipient. At 12 months, visual and biomicroscopic measures do not show deterioration and inflammation remains under control with oral azathioprine as maintenance regime. The management of PUK includes both systemic immunosuppression and tectonic procedures to preserve the globe integrity. Diverse surgical techniques have been attempted, but no definitive guidelines are available. Decentered large SALK is a simple technique that can yield acceptable visual results.

Surgical alternatives to keratoplasty in microbial keratitis

Penetrating keratoplasty is often required in microbial keratitis not responding to the standard treatments available or the development of complications like corneal perforation. Performing keratoplasty in microbial keratitis has several challenges, the major ones being the availability of donor corneal tissue and the poor success of the corneal graft performed in such a setting. For overcoming these challenges, several alternatives to keratoplasty have been described. Broadly, these options could be categorized into autologous tissues such as conjunctival and tenon tissue, synthetic products like tissue adhesives and therapeutic contact lenses, or biological tissues like amniotic membrane graft. These alternative modalities are not universal. They have their specific indications in microbial keratitis. Most of these alternatives are useful only for small corneal perforations. While autologous tissues are cost-effective and readily available, lack of tectonic support is a significant limitation. Tissue adhesives are excellent alternatives in terms of tectonic support, but surface irregularity and tissue reaction are their potential limitations. The amniotic membrane is useful for small corneal perforations, but availability, cost, and poor tectonic support restrict its use. Herein, we discuss these various alternatives to keratoplasty in microbial keratitis, their indications, advantages, disadvantages, and the various techniques of performing these procedures.

Shaped corneal transplantation surgery

Since its inception in 1905, keratoplasty techniques have continuously evolved. Shaped keratoplasty procedures have allowed corneal surgeons to use complex graft-host junctions and non-circular graft designs to optimise wound strength and healing, facilitate early suture removal and expedite visual rehabilitation. While this was initially limited to penetrating procedures, shaped lamellar keratoplasty techniques have since emerged. Furthermore, the arrival of femtosecond laser has dramatically increased the range of graft designs available to surgeons, due to the technology's ability to precisely cut complex wound edges. This review describes the broad range of shaped keratoplasty grafts currently available and elaborates on their respective advantages and disadvantages in relation to conventional keratoplasty.