Tectonic corneal lamellar grafting for severe scleral melting after pterygium surgery

Necrotizing Scleritis: A Review

Necrotizing scleritis is the most destructive and vision-threatening form of scleritis. Necrotizing scleritis can occur in systemic autoimmune disorders and systemic vasculitis, as well as following microbial infection. Rheumatoid arthritis and granulomatosis with polyangiitis remain the commonest identifiable systemic diseases associated with necrotising scleritis. Pseudomonas species is the most common organism causing infectious necrotizing scleritis, with surgery the most common risk factor. Necrotizing scleritis has the highest rates of complications and is more prone to secondary glaucoma and cataract than other phenotypes of scleritis. The differentiation between non-infectious and infectious necrotizing scleritis is not always easy but is critical in the management of necrotizing scleritis. Non-infectious necrotizing scleritis requires aggressive treatment with combination immunosuppressive therapy. Infectious scleritis is often recalcitrant and difficult to control, requiring long-term antimicrobial therapy and surgical debridement with drainage and patch grafting due to deep-seated infection and the avascularity of the sclera.

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.

Management of scleral melt

Scleral melting, while rare, can lead to significant ocular morbidity. Several possible risk factors for scleral melt have been identified, such as infection, autoimmune disease, trauma, and post-surgical state, and these may act in combination with each other. Treatment should be tailored according to the etiology and severity of the scleral melt. Medical management may be indicated, especially in cases of autoimmune-related melt; however, surgical procedures are often necessary due to compromised ocular integrity and limited penetration of medications into the avascular sclera. An understanding of the surgical options available and their operative outcomes is particularly important when choosing the appropriate treatment protocol for each patient.

Topical Erythropoietin for Treatment of Scleral Necrosis

PURPOSE

To investigate the safety and efficacy of topical erythropoietin for the treatment of scleral necrosis.

METHODS

This study enrolled eight consecutive patients with scleral necrosis due to previous ocular surgery, rheumatoid arthritis-associated necrotizing anterior scleritis, and thermal and chemical burns. Conventional treatments failed to heal avascular scleral lesions in all eyes. Patients were treated with topical erythropoietin (3000 IU/mL) four times a day.

RESULTS

The mean patient age was 37.6 ± 15.5 years. The interval between the development of scleral necrosis and initiation of topical erythropoietin was 25.6 ± 12.0 days. The necrotic sclera completely healed within 31.9 ± 16.9 days in all patients. The avascular lesions did not recur, and there was no evidence of side effects during the study.

CONCLUSION

Our results showed that topical erythropoietin could be safely used to manage scleral necrosis. Randomized clinical trials are needed to further explore the efficacy of this intervention in patients with avascular scleral lesions.

Implementation and Application of an Intelligent Pterygium Diagnosis System Based on Deep Learning

Objective: This study aims to implement and investigate the application of a special intelligent diagnostic system based on deep learning in the diagnosis of pterygium using anterior segment photographs.

Methods: A total of 1,220 anterior segment photographs of normal eyes and pterygium patients were collected for training (using 750 images) and testing (using 470 images) to develop an intelligent pterygium diagnostic model. The images were classified into three categories by the experts and the intelligent pterygium diagnosis system: (i) the normal group, (ii) the observation group of pterygium, and (iii) the operation group of pterygium. The intelligent diagnostic results were compared with those of the expert diagnosis. Indicators including accuracy, sensitivity, specificity, kappa value, the area under the receiver operating characteristic curve (AUC), as well as 95% confidence interval (CI) and F1-score were evaluated.

Results: The accuracy rate of the intelligent diagnosis system on the 470 testing photographs was 94.68%; the diagnostic consistency was high; the kappa values of the three groups were all above 85%. Additionally, the AUC values approached 100% in group 1 and 95% in the other two groups. The best results generated from the proposed system for sensitivity, specificity, and F1-scores were 100, 99.64, and 99.74% in group 1; 90.06, 97.32, and 92.49% in group 2; and 92.73, 95.56, and 89.47% in group 3, respectively.

Conclusion: The intelligent pterygium diagnosis system based on deep learning can not only judge the presence of pterygium but also classify the severity of pterygium. This study is expected to provide a new screening tool for pterygium and benefit patients from areas lacking medical resources.

Long-term Outcome of Surgical Treatment with Various Reinforcement Material Grafts on Scleromalacia

Purpose: To investigate the long-term efficacy and stability of the use of various reinforcement material grafts on scleromalacia.Methods: This retrospective study was conducted on scleromalacia patients who underwent surgical treatment with reinforcement material grafts from January 2012 to March 2019. The choice of amniotic membrane, Tenon’s capsule, acellular sclera, or collagen matrix implanted in the area of scleromalacia was made based on disease severity. Amniotic membrane transplantation with a pedicular rotatory inferior conjunctival flap was performed to prevent having a bare sclera. The patient demographics, cause of scleromalacia, best-corrected visual acuity (BCVA), recurrence rate, postoperative complications, and restoration appearance were evaluated.Results: A total of 58 patients (58 eyes) were enrolled in this study. The mean age of patients was 65.7 ± 9.6 years, and 32 patients (55.2%) were women. The mean follow-up period was 28.1 ± 17.3 months. The most common cause of scleromalacia was pterygium operation (53 patients, 91.4%). The reinforcement materials were mainly amniotic membrane (31 patients, 53.4%) and acellular sclera (15 patients, 25.7%). There was no recurrence of scleromalacia or structural instability during the follow-up period. The preoperative and postoperative mean BCVA values were 0.24 ± 0.24 and 0.21 ± 0.23 logMAR, respectively. Wound dehiscence (three patients, 5.2%) and conjunctival cyst (three patients, 5.2%) occurred with the highest frequency.Conclusions: The use of the appropriate reinforcement material graft according to the severity of scleromalacia and amniotic membrane transplantation using a pedicular rotatory inferior conjunctival flap to prevent a bare sclera can be effective for treating scleromalacia, without long-term recurrence.

Donor Cornea Use in Scleral Surface Reconstruction

Objectives:

To investigate the indications for and results of treating scleral surface problems with donor corneal grafts that are not used in keratoplasty surgery or are left over from keratoplasty.

Materials and Methods:

The records of 16 patients in whom corneal tissue was used to repair a scleral tissue defect or cover an exposed glaucoma drainage implant were evaluated retrospectively. Partial-thickness grafts were prepared using a combined microkeratome system with artificial anterior chamber in 10 eyes and by manual dissection in 3 eyes. Full-thickness grafts were used in 3 eyes.

Results:

There were 8 female and 8 male patients aged 5-79 years (mean: 39.37±24.68). Indications for the use of corneal tissue on the scleral surface were limbal dermoid excision (n=2), pterygium surgery (n=1), intraocular lens removal and scleral fixation intraocular lens (SFIOL) implantation (n=1), exposed SFIOL suture coverage (n=1), trauma (n=2), scleral tissue loss due to repeated glaucoma surgeries (n=5), and exposed glaucoma drainage implant (n=4). The patients were followed for 6-42 months (mean: 14.37±9.14). None of the patients had graft infection, thinning, immunological graft rejection, or vision loss during follow-up. Tectonic lamellar grafts did not adversely affect final visual acuity in any case. At final examination, a good combination of graft and recipient tissue, a smooth ocular surface, and a cosmetic appearance were achieved in all eyes.

Conclusion:

Donor corneas that are not suitable for corneal transplantation or left over from the cornea transplant can be used in patients with scleral tissue loss due to various pathologies and in the treatment of glaucoma drainage implant erosion. In these cases, the use of corneal grafts provides a good ocular surface restoration and cosmetic appearance. The effectiveness and safety of this method should be investigated with large patient series and long follow-up times.

Infectious Scleritis: Pathophysiology, Diagnosis, and Management

ABSTRACT

Infectious scleritis (IS) is a rare and severe ocular disorder responsible for approximately 5%-15% of all scleritis cases. It is often associated with a poor prognosis due to its similar clinical presentation to autoimmune scleritis, resulting in a delayed diagnosis and treatment. Therefore, differentiating between infectious and noninfectious entities is critical. Several details extracted from the patient's history and clinical examination can raise suspicion for infection. The most common predisposing factor is previous ocular surgery, especially pterygium, cataract, and vitreoretinal surgeries. Ocular trauma, poor contact lens hygiene, "eye-whitening" procedures, and subtenon triamcinolone injections have also been implicated. Clinical features of infection include the presence of scleral necrosis, hypopyon, unifocal or multifocal scleral abscesses, and mucopurulent discharge. Thorough diagnostic testing is essential before excluding infection as a possibility. Empiric broad-spectrum topical and systemic antibiotic therapy should be initiated while awaiting laboratory results and adjusted accordingly. Most IS cases require both aggressive medical and surgical treatment, and various studies have reported favorable outcomes with this combination. At this time, there is no consensus on the management of this severe ocular condition, and future studies are needed to establish clear treatment guidelines.

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.

Inhibition of enhancer of zeste homolog 2 prevents corneal myofibroblast transformation in vitro

PURPOSE

Corneal fibroblast can be transformed into corneal myofibroblasts by TGF-β1. Enhancer of zeste homolog 2 (EZH2) upregulation has been observed in the occurrence of other fibrotic disorders. We investigated the role of EZH2 in the progression of corneal fibrosis and the antifibrotic effect of EZH2 inhibition in corneal fibroblasts (CFs).

METHODS

Primary CFs were isolated from corneal limbi and the CFs were treated with TGF-β1 to induce fibrosis. EPZ-6438 and EZH2 siRNA were used to inhibit EZH2 expression. Myofibroblast activation and extracellular matrix (ECM) protein synthesis was detected by quantitative real-time PCR, western blotting, and immunofluorescence staining assay. The functions of myofibroblast were evaluated by cell migration and collagen gel contraction assays. Molecular mechanisms involved in EZH2 inhibition were investigated by RNA sequencing.

RESULTS

TGF-β1 activated EZH2 expression in CFs. Treatment with EPZ-6438 (5 μM) and EZH2 siRNA considerably suppressed corneal myofibroblast activation and ECM protein synthesis in CFs induced by TGF-β1 when compared to the control group. EPZ-6438 (5 μM) suppressed cell migration and gel contraction in CFs. RNA sequencing results revealed that antifibrotic genes were activated after EZH2 inhibition to suppress corneal myofibroblast activation.

CONCLUSION

Inhibition of EZH2 suppresses corneal myofibroblast activation and ECM protein synthesis, and could serve as a novel therapeutic target for preventing corneal scarring.

Evaluation of Conjunctival Autografting Augmented with Mitomycin C Application versus Ologen Implantation in the Surgical Treatment of Recurrent Pterygium

Objectives

To evaluate the safety and efficacy of augmenting conjunctival autografting with intraoperative mitomycin C (MMC) application versus Ologen implantation in the management of recurrent pterygium.

Materials and Methods

This prospective randomised study included 63 eyes of 63 patients, with recurrent nasal pterygium, who presented to the outpatient clinic of Menoufia University Hospital in Shebin El Kom and Manshiet Soltan from January 2016 to December 2019. Patients were randomly enrolled into two groups. Group A included 32 eyes of 32 patients who underwent conjunctival autografting augmented with the topical application of MMC (0.2 mg/mL), and group B included 31 eyes of 31 patients who underwent conjunctival autografting augmented with Ologen implantation. All the patients underwent follow-up examinations for a period of 24 months. During each visit, a complete ophthalmic examination was performed. Pterygium regrowth of 1 mm or more, over the cornea, was considered a recurrence.

Results

In the MMC group, no recurrence was reported during the 24-month follow-up period. In the Ologen implantation group, recurrence was reported in 2 (8%) eyes. The time interval from surgery to recurrence was 5 months in one case and 8 months in the other. No other serious postoperative complications were reported, and there was no statistically significant difference between the groups in this regard.

Conclusion

Ologen implantation with conjunctival autografting shows promising results in the surgical management of recurrent pterygium with mild non-vision-threatening postoperative complications comparable to that of MMC application with conjunctival autografting. Registration number: ClinicalTrials.govNCT04419038.

The clinical and pathogenic spectrum of surgically-induced scleral necrosis: A review

The onset of scleral necrosis after ocular surgery may have catastrophic ocular and systemic consequences. The two most frequent surgeries causing surgically-induced scleral necrosis (SISN) are pterygium excision and cataract extraction. Several pathogenic mechanisms are involved in surgically induced scleral necrosis. All of them are poorly understood. Ocular trauma increasing lytic action of collagenases with subsequent collagen degradation, vascular disruption leading to local ischemia, and immune complex deposition activating the complement system represents some of the events that lead to scleral necrosis. The complex cascade of events involving different pathogenic mechanisms and the patient's abnormal immune response frequently leads to delayed wound healing that predisposes the development of scleral necrosis. The management of SISN ranges from short-term systemic anti-inflammatory drugs to aggressive immunosuppressive therapy and surgical repair. Therefore, before performing any ocular surgery involving the sclera, a thorough ophthalmic and systemic evaluation must be done to identify high-risk patients that may develop SISN.

Topical Erythropoietin as a Novel Treatment for Necrotizing Scleritis After Pterygium Surgery: A Pilot Study

PURPOSE

To share our initial experience with the innovative use of topical erythropoietin for the treatment of necrotizing scleritis manifesting immediately after pterygium excision surgery.

METHODS

This study enrolled 3 patients who developed necrotizing scleritis immediately after undergoing pterygium excision. All cases with pterygium were primary, and topical mitomycin C and conjunctival autografts were used at the time of surgery. Noninvasive therapy that included ophthalmic lubricants and topical and systemic corticosteroids failed to improve the avascular scleral lesions. The patients were prescribed erythropoietin-containing drops (3000 U/mL) every 6 hours in addition to topical antibiotics and lubricant. The effect of topical erythropoietin on the healing process of avascular scleral lesions was investigated, and its ocular and systemic side effects were evaluated.

RESULTS

The mean age of the participants was 69.0 ± 14.8 years, and 2 of the 3 eyes belonged to male subjects. The time between pterygium surgery and presentation to our clinic was 33.0 ± 14.7 days. There were no infectious causes or underlying systemic diseases in any of the cases. After treatment with topical erythropoietin for an average of 34.3 ± 20.3 days, the lesions were completely vascularized in all 3 eyes without any ocular or systemic adverse effects. The patients were followed up for an average of 126 ± 94 days after discontinuation of erythropoietin. There was no evidence of recurrence during the last examination in any of the eyes.

CONCLUSIONS

Topical erythropoietin might be a safe and an effective method for treating cases of necrotizing scleritis that manifests immediately after pterygium surgery.

Necrotizing scleritis after strabismus surgery in Treacher Collins syndrome

Objective: To describe a case of surgically induced scleral necrosis in Treacher Collins syndrome after strabismus surgery. Methods: A 19-year-old girl underwent bilateral squint surgery. Two weeks postoperatively, she presented with subconjunctival abscess in the left eye. The surrounding conjunctiva was markedly inflamed with raised edges. Surgical debridement, microbiological evaluation and medical management were started immediately. Screening for autoimmune and vasculitic conditions did not provide any positive results. Results: On subsequent follow-up, conjunctival retraction and an area of scleral necrosis with thinning was noted. Significant healing with antibiotics and steroids was noted within one week. The integrity of the globe was well maintained and no further procedure for tectonic support was performed. Conclusion: Surgically induced scleral necrosis can be immune-mediated or following surgical site infection. Pre-existing scleral thinning due to neuroectodermal apoptosis in Treacher Collins syndrome remains a possible explanation for the accelerated necrotising scleritis in our case.

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.

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.

Fifteen-year results of a randomized controlled trial comparing 0.02% mitomycin C, limbal conjunctival autograft, and combined mitomycin C with limbal conjunctival autograft in recurrent pterygium surgery

PURPOSE

To compare the long-term outcomes of recurrent pterygium surgery between three different techniques.

METHODS

We performed a 15-year follow-up study of a randomized controlled study on surgical management of recurrent pterygium. Group 1 received limbal conjunctival autograft (LCAU); group 2 received intraoperative mitomycin C (MMC) 0.02% for 5 min; and group 3 received combined LCAU + MMC 0.02% for 5 min. Consecutive patients enrolled in the original study (from April 2001 to March 2003) were invited back for a detailed clinical examination to document the long-term outcomes. The main outcome measures included the recurrence rate, residual conjunctival bed status, and complications from any of the surgical methods.

RESULTS

Sixty-two patients were recruited in the original study. Eight patients had passed away and 12 patients were uncontactable or not responded. One patient who had bilateral operations refused to return for follow-up and one eye had insufficient data for analysis. Finally, 40 eyes of 40 patients were included for analyses. One eye developed a recurrence over 15 years and none required a tertiary pterygium operation. The patient received LCAU for a temporal recurrent pterygium developed a 2.2-mm recurrence.

CONCLUSIONS

All three techniques yielded favorable outcomes for patients with recurrent pterygium. The use of LCAU was associated with better cosmetic outcome.

Tectonic corneal lamellar grafting for surgically-induced necrotizing scleritis after strabismus surgery: Case report & literature review

Purpose

To report the first case of infectious surgically-induced necrotizing scleritis following strabismus surgery which was treated successfully with a tectonic corneal graft.

Observations

We report a case of surgically-induced necrotizing scleritis after strabismus surgery in a 61-year-old gentleman with gout and a subconjunctival abscess. Surgical drainage of the subconjunctival abscess led to a diagnosis of scleral melt which was subsequently treated with a tectonic corneal graft along with aggressive medical management. Over the following eight months, the patient showed no signs of endophthalmitis, graft necrosis, nor graft dehiscence, and serial anterior segment optical coherence tomography imaging demonstrated anatomic stability.

Conclusions and importance

This case offers further insights into a rare but vision-threatening and potentially life-threatening diagnosis. In conjunction with aggressive local and systemic treatment, tectonic lamellar keratoplasty provides good therapeutic and tectonic results for scleral necrosis after strabismus surgery. This case also demonstrates the importance of screening for associated systemic risk factors in any patient with scleritis for appropriate, targeted therapy.

Conjunctival Flap with Biodegradable Collagen Matrix Implantation for the Treatment of Scleromalacia after Periocular Surgery

Purpose: To report a new surgical procedure using biodegradable collagen matrix (Ologen) implantation with conjunctival flap for reconstruction of scleromalacia after periocular surgery. Methods: A total of 26 areas of 25 eyes in 25 patients were included. We divided all eyes according to the preoperative extent of calcified plaque or scleral defect as follows: small, large, and large and severe. Morphologic outcomes were graded from 0 to 7, with higher scores indicating worse cosmetic outcomes. Results: Mean follow-up period was 8.3 ± 5.6 months. No eyes showed recurrence or specific complications related to Ologen such as implant extrusion or allergic reaction. Minor complications such as flap vessel engorgement and flap hypertrophy were easily treated. Mean morphologic outcome scores were 1.8, 2.4, and 5.3 in groups 1, 2, and 3, respectively. Discussion: The combined surgery may be an effective and safe procedure for the treatment of scleromalacia after periocular surgeries.

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.

Letter to the Editor: Corneoscleral Melt 50 Years after Excision of Pterygium

PURPOSE

To report a case of corneoscleral melt that occurred 50 years after resection of pterygium with postoperative administration of mitomycin C (MMC).

RESULTS

A 93-year-old woman developed acute corneal perforation and scleral melt in her left eye at 50 years after pterygium surgery with postoperative topical MMC. She underwent limbal transplantation. The anterior chamber reformed postoperatively and her intraocular pressure was normal. At 12 months after transplantation, best-corrected visual acuity was 20/500 and the graft-host junction was well apposed.

CONCLUSION

This case shows that corneoscleral melt can occur even 50 years after resection of pterygium combined with postoperative topical MMC.

Pericardial patch graft repair of severe localized scleral thinning encountered during strabismus surgery

This article presents a surgical technique using a pericardial patch for the permanent repair of severe scleral thinning encountered during strabismus surgery. In the present case scleral thinning resulted from buckle removal. Familiarity with this technique may prove important for the strabismus surgeon treating patients with a history of surface ocular hardware or disease-induced scleral thinning. This video article may be viewed atjaapos.org.

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

PURPOSE

To evaluate the anatomical outcomes of corneal patch grafts in patients with progressive scleral necrosis secondary to plaque radiotherapy used for uveal malignant melanoma management.

METHODS

In this case series, 4 patients with progressive scleral necrosis after Ru-106 plaque radiotherapy underwent corneal patch grafts with the anterior corneal button from Descemet stripping automated endothelial keratoplasty donor tissue to strengthen the sclera and to improve appearance of the eye.

RESULTS

Ciliary body involvement was evident in all cases. All 4 patients had received radiation doses of 400 Gy or more to the tumor base. The mean time interval between plaque radiotherapy and scleral necrosis was 24.5 ± 7.5 months (range, 18-34 months). Successful results were achieved in all patients with tectonic graft. No patients experienced graft thinning, rejection, infection, or tumor recurrence in a mean follow-up of 28.5 ± 7.9 months (range, 20-39 months).

CONCLUSIONS

Corneal patch graft by anterior corneal button from Descemet stripping automated endothelial keratoplasty donor tissue results in successful restoration of globe integrity and satisfactory cosmetic appearance in patients with scleral necrosis secondary to plaque radiotherapy.

Results of pterygium excision adjunct with conjunctival autograft transplantation for primary pterygium by ophthalmology trainees

To evaluate the results of pterygium excision with conjunctival autograft transplantation for primary pterygium performed by trainee ophthalmologists. Design Prospective interventional case series. Setting A tertiary eye care center in northern Thailand. Participants Patients with primary pterygium recruited from July 2011 to August 2012. Intervention In all cases, the affected eye underwent pterygium excision followed by a superior conjunctival autograft carried out by trainee ophthalmologists. Main outcome measure The recurrence of pterygium and other post-operative complications. Results Sixty-two eyes from 54 patients were studied. There were 36 females (66.7 %) and 18 males (33.3 %). The mean age of the patients was 54.5 (±9.8) years with the mean corneal invasion measured at 3.3(±0.8) mm. Pterygium morphologies of Grade 1, Grade 2, and Grade 3 were 33.9, 48.4, and 17.7 %, respectively, with the mean follow-up time of 17.3 (±7.9) months. Pterygium recurred in the cornea of six eyes (9.7 %). All recurrences occurred within 6-month post-operation. Other post-operative complications included conjunctival recurrence (4.8 %), graft retraction (3.2 %), conjunctival cyst (3.2 %), and increased intraocular pressure (1.6 %). The recurrence of pterygium was not associated with the patient age (p = 0.72), occupation (p = 0.23), sun exposure time (p = 0.18), pterygium duration (p = 0.22), pterygium size (p = 0.67), or pterygium morphology (p = 0.85). Conclusion The recurrence rate and post-operative complications of pterygium excision with conjunctival autograft performed by trainee ophthalmologists were within acceptable limits. All recurrence occurred within 6 months after surgery.

Prophylactic removal and microbiological evaluation of calcified plaques after pterygium surgery

PURPOSE

The aim of this study was to investigate microbiological characteristics of prophylactically removed calcified plaques developed after pterygium excision, and to evaluate risk factors for the growth of microorganisms.

METHODS

Only exposed calcified plaques developed at the same site of previous pterygium excision were prospectively removed in 15 eyes of 14 patients. Plaques were completely removed, divided into small pieces and evaluated for microbiological identification. Underlying scleral defects were reconstructed using a conjunctival autograft, amniotic membranes and scleral patch grafts according to the size and depth of the defects. Based on the results of microbiologic cultures, eyes were divided into two groups and risk factors for microbial growth were analyzed.

RESULTS

At surgery, the mean age of the patients was 71.2 ± 5.8 years and 71.4 % were females. The mean time interval between pterygium excision and calcified plaque removal was 19.3 ± 13.8 years. Six of 15 (40 %) removed plaques showed bacterial growth, and Stenotrophomonas maltophilia was the most frequently isolated microorganism. The size of calcified plaques was the only risk factor for culture-positive results (p = 0.045). Underlying scleral defects were successfully repaired without any serious complication.

CONCLUSIONS

Microorganisms can be isolated from calcified plaques developed at the site of previous pterygium excision, and the size of plaques is the only risk factor for culture-positive results. To remove potential source of infection, prophylactic removal of calcified plaques and scleral surface reconstruction should be considered, especially when the plaques are exposed and large.

Dellen and corneal perforation after bilateral pterygium excision in a patient with no risk factors

Corneal perforation associated with dellen is a rare but serious complication of a primary pterygium excision. In this case report, we describe a 60-year-old man who underwent a corneal perforation in the centre of corneal dellen in his right eye and corneal dellen in his left eye after the surgical treatment of a bilateral pterygium with a bare sclera technique without adjunctive therapy. He was successfully treated with lamellar keratoplasty in his right eye and a conservative approach in his left eye, consisting of the use of artificial tears, antibiotic ointment and a patch. The clinical evidence from this brief interventional case report indicates that topical lubricants are proper therapy for corneal dellen. However, if corneal perforation is observed, lamellar keratoplasty is a good option.

Biodegradable collagen matrix (Ologen™) implant and conjunctival autograft for scleral necrosis after pterygium excision: two case reports

BACKGROUND

Scleromalacia, in the form of scleral thinning, melting, and necrosis, is a potentially serious complication of pterygium excision. This study introduces a new biodegradable material, Ologen™ collagen matrix (OCM), to repair scleral thinning as an alternative to preserved scleral tissue, and evaluates the long-term outcomes of OCM for ocular surface reconstruction surgery.

CASE PRESENTATION

Two cases of possibly mitomycin C (MMC)-associated marked scleral thinning after pterygium excision with 0.02 % topical MMC for 2-weeks were included in this study. An OCM graft at the scleral thinning area and conjunctival autograft (CAU) were performed on both patients. The scleral defect size was measured and its margin was marked with a biopsy punch. The margin of the scleral thinning area was trimmed by Vannas scissors and the OCM was cut using a circular-shape biopsy punch of the same size. The OCM was sutured with a recipient scleral wall using 10-0 nylon interrupted sutures. Free CAU was harvested from the superonasal bulbar conjunctiva with a punch biopsy 1-mm larger in diameter than that of the OCM. The previously sutured OCM bed was covered with CAU and the graft was secured with 10-0 nylon interrupted sutures. Both patients were examined periodically for over two years by assessing graft thickness and surface vascularization using a slit lamp biomicroscope. Reepithelialization of the ocular surface was observed within three to six days after surgery. Ocular discomfort and inflammation ceased in both patients as the ocular surface quickly stabilized. The entire graft site remained intact and provided a good healthy ocular surface with fluorescein stain negative intact epithelium and good vascularization of grafted conjunctiva. Epithelial defects and scleral thinning did not recur in either patient over the two year follow-up period.

CONCLUSION

For treatment of a possibly MMC-associated scleral necrosis following the surgical excision of the pterygium, an OCM graft with CAU is highly recommended for good clinical outcomes and low recurrence rates. With the clinical results of this study, the new biodegradable Ologen™ collagen matrix qualifies as an alternative treatment to scleral tissue for ocular surface reconstruction.

Autologous advanced tenon grafting combined with conjunctival flap in scleromalacia after pterygium excision

Purpose. To evaluate the efficacy of autologous tenon grafting combined with conjunctival flap as a treatment for scleromalacia or scleral thinning after pterygium excision without any additional donor graft tissue. Methods. Twenty-six cases underwent autologous advanced tenon grafting combined with sliding or rotating conjunctival flap for scleromalacia after pterygium surgery ranging from 2 years to 30 years. The extent of scleral defect measured from 2.0 mm to 6.8 mm in diameter. The cosmetic outcome was defined as complete resolution of scleromalacia or completely conjunctival reepithelialization and firm adhesion between subtenon and scleral tissue over scleral thinning without significant complications. Results. All cases achieved the covering of conjunctival and tenon or subtenon tissue over scleromalacia or scleral thinning with this procedure. Preoperative pain, inflammation, and choroidal exposure disappeared after surgery. Immediate postoperative complications, such as large wound dehiscence or reopening of the scleral wound, did not occur in any of the patients. There were no significant clinical complications during the mean postoperative follow-up period of 14.17 months in all cases. Conclusions. We obtained excellent outcome with fewer complications after autologous advanced tenon graft and conjunctival flap, without an additional donor graft, in scleromalacia or scleral thinning caused by previous pterygium excision.

Randomized trial comparing multilayer amniotic membrane transplantation with scleral and corneal grafts for the treatment of scleral thinning after pterygium surgery associated with beta therapy

PURPOSE

The aim of this study was to compare the use of multilayer amniotic membrane transplantation (AMT) with lamellar corneal transplantation (LCT) and lamellar scleral transplantation (LST) for the treatment of scleral thinning after pterygium surgery associated with beta therapy.

METHODS

Twenty-six eyes from 26 different patients with scleral thinning as a consequence of beta therapy after pterygium surgery were evaluated at the Federal University of São Paulo, Brazil. Ophthalmologic examination and ultrasound biomicroscopy were performed to assess scleral thinning before the transplant surgery and then repeated at 30, 90, and 180 days after surgery. An increase in scleral thickness, epithelialization of the ocular surface, and preservation of the ocular globe were the main outcome measures.

RESULTS

Irrespective of the surgical technique used (AMT, LCT, or LST), no clinical or statistical changes in corrected distance visual acuity were found in any of the patients during this study. The median preoperative scleral thickness was similar in all 3 groups: AMT = 0.45 mm, LST = 0.48 mm, and LCT = 0.52 mm (P = 0.257); however, 6 months after surgery, the median thickness in the AMT group (0.19) was significantly less than that of the LCT group (0.57) (P = 0.27) or the LST group (0.76) (P = 0.19). Epithelialization occurred in all the patients.

CONCLUSIONS

LCT was the best option for the structural treatment of scleral thinning, followed by LST with a conjunctival flap. A high rate of reabsorption was found with AMT, which was the least effective of the 3 therapeutic options and should not be used for this condition.

Delayed manifestation of bilateral scleral thinning after I-BRITE(®) procedure and review of literature for cosmetic eye-whitening procedures

Purpose

To report a case of delayed-onset bilateral scleral thinning and calcium deposition following a cosmetic ocular-whitening procedure (I-BRITE^®).

Methods

A 33-year-old male patient with a history of right-sided ptosis repair and left-sided anterior uveitis had previously undergone bilateral I-BRITE treatment for chronic conjunctival hyperemia. Four years after the procedure, the patient was referred to our institution with bilateral scleral thinning and overlying calcific depositions. A literature review was performed through PubMed from 1980 through 2014 using the search terms ‘cosmetic’, ‘ocular’, ‘conjunctivectomy’, ‘regional conjunctivectomy’, ‘I-BRITE’, ‘eye-whitening’, ‘scleritis’, ‘necrotizing scleritis’, ‘anterior uveitis’, ‘mitomycin C’, ‘5-fluorouracil’, and ‘bevacizumab’, along with associated cross-referencing from relevant articles.

Results

Examination of the patient revealed bilateral necrotizing scleritis within the nasal region of both eyes. Calcified plaques were also present within the areas of scleromalacia, along with epithelial defects demonstrated with fluorescein staining. Although evidence of previous intraocular inflammation was apparent within the left eye, there were no active signs of inflammation evident within either eye on initial presentation. Complication rates reported in the literature include: scleral thinning (1.8%), calcific plaque formation (2.9%), fibrovascular proliferation (13%), diplopia (1.2%), elevation of intraocular pressure (4.2%), and recurrence of conjunctival hyperemia (2.1%).

Conclusion

Cosmetic ocular whitening procedures have an attendant high complication rate, and have been associated with several adverse postoperative complications, which have in turn generated several reservations regarding the veritable benefit of the procedure. Many postsurgical complications may demonstrate delayed apparition, varying from several months to several years after primary surgical intervention as in the case reported here.

Use of an Autologous Lamellar Scleral Graft to Repair a Scleral Melt After Mitomycin Application

Mitomycin (MMC) has been associated with a variety of complications, including corneoscleral melt. We report the successful repair of a scleral melt with a partial thickness autologous scleral graft of the scleral melting. A 55-year-old male patient underwent pterygium resection surgery and intraoperative MMC application. The patient developed a deep melting area that almost reached the choroid layer at the nasal sclera. We repaired scleral defect with a partial thickness autologous scleral graft. Closure of an MMC-associated scleral melting area with an autologous partial thickness scleral graft is an effective and easy-to-use method.

Cross-linking as an adjuvant treatment for tectonic corneal lamellar graft preparation

PURPOSE

To describe a new surgical approach for the tectonic reconstruction of the anterior ocular segment and the management of scleral and conjuctival melting.

METHODS

Case series of patients demonstrating anterior segment anomalies, such as scleral and conjunctival melting. The anterior stromal part of a pre-cut corneal graft for Descemet's stripping automated endothelial keratoplasty (DSAEK) was cross-linked with riboflavin and ultraviolet A irradiation and was used to cover scleral (scleral melting in a patient with necrotizing scleritis, one case) and conjuctival (dehiscence of the conjunctiva in patients with anti-glaucomatous valve exposure, two cases) areas. The endothelial part of all corneal grafts was used for DSAEK in patients with need of corneal endothelial transplantation.

RESULTS

Repair of scleral and conjuctival melting was successful in all cases. No intra- or post- operative complications occured. Visual acuity of all patients remained stable during the follow up period. One year postoperatively the corneal graft remained in place and no signs of inflammation were evident, while all grafts were epithelialized.

CONCLUSIONS

The use of cross-linked corneal graft for the tectonic reconstruction of the anterior ocular segment represents an adequate surgical approach for the management of scleral and conjuctival melting; while, at the same time it offers the advantage of using one corneal graft for two recipients.

Necrotizing scleritis after strabismus surgery in thyroid eye disease

Surgically induced necrotizing scleritis, which can lead to potentially devastating consequences, is a rare sequela to many types of ocular surgeries. We describe a 58-year-old woman who developed necrotizing scleritis following strabismus surgery for thyroid ophthalmopathy. Tectonic corneal patch grafting resulted in a favorable outcome.

Excimer laser surface ablation: a review of recent literature

The aim was to review the recently published literature on excimer laser surface ablation procedures, including photorefractive keratectomy (PRK), laser sub-epithelial keratomileusis (LASEK), microkeratome-assisted PRK (epi-LASIK) and trans-epithelial (laser-assisted) PRK, to help elucidate where and how surface ablation may best fit into current refractive surgical practice. The emphasis was on publications within the last three years and included systemic reviews, meta-analyses and randomised controlled trials. Where such evidence did not exist, selective large series cohort studies, case-controlled studies and case series with follow-up preferably greater than six months were examined and included. Refractive and visual outcomes are excellent and comparable to those after LASIK even in complex cases after previous corneal surgery. Indeed, surface ablation combined with corneal collagen cross-linking may be used in selected eyes with biomechanical instability, where LASIK is contraindicated. In addition, there is evidence to suggest that there may be less induction of higher order aberrations with surface techniques. Long-term stability and safety appear to be extremely satisfactory. The literature supports the use of modern excimer laser surface treatments, with outcomes comparable to those after LASIK and evidence of less induction of higher-order aberrations. Follow-up studies at 10 to 20 years indicate excellent stability and safety.

Lamellar corneal transplantation

Penetrating keratoplasty (PK) has been the gold standard for the surgical treatment of most corneal pathologies; lamellar keratoplasty that only replaces the diseased corneal layers has recently evolved as an alternative, however. Innovations in surgical technique and instrumentation provide visual outcomes comparable to PK. We review the indications and outcomes of various techniques of anterior lamellar surgery developed to treat stromal disorders. Similarly, we discuss posterior lamellar keratoplasty techniques such as Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty. Posterior lamellar keratoplasty provides faster visual rehabilitation than PK in cases of Fuchs endothelial dystrophy and pseudophakic bullous keratopathy. In addition, for medically unresponsive infectious keratitis, therapeutic anterior lamellar keratoplasty yields similar graft survival to PK without an increased risk of disease recurrence.

Necrotizing scleritis as a complication of cosmetic eye whitening procedure

Background

We report necrotizing scleritis as a serious complication of a cosmetic eye whitening procedure that involves the use of intraoperative and postoperative topical mitomycin C.

Findings

This is a single case report. A 59-year-old Caucasian male with a history of blepharitis status post uncomplicated LASIK refractive surgery reported chronic conjunctival hyperemia for 15 years prior to undergoing a cosmetic eye whitening procedure. He presented to our clinic 12 months after the cosmetic eye whitening procedure with progressive bilateral necrotizing scleritis and scleral calcification.

Conclusions

Chronic conjunctival hyperemia may prompt patients to seek surgical correction with cosmetic eye whitening procedures. However, conjunctival hyperemia secondary to tear deficiency and evaporative dry eye may predispose to poor wound healing. Serious complications including necrotizing scleritis may result from cosmetic eye whitening procedures and the use of topical mitomycin C.

Recurrence and complications after 1,000 surgeries using pterygium extended removal followed by extended conjunctival transplant

OBJECTIVE

To document the recurrence rate and complication rate of pterygium extended removal followed by extended conjunctival transplant.

DESIGN

An open, prospective study of consecutive pterygium patients undergoing pterygium extended removal followed by extended conjunctival transplant.

PARTICIPANTS AND CONTROLS

The study included 1000 consecutive patients undergoing pterygium surgery between August 2001 and September 2009.

INTERVENTIONS

All patients underwent pterygium extended removal followed by extended conjunctival transplant by the author with attempted follow-up for 1 year.

MAIN OUTCOME MEASURES

Recurrence and complication rates.

RESULTS

Follow-up of >1 year was obtained in 99% of patients. There was 1 recurrence in the 1000 surgeries (0.1%) with 95% confidence intervals of 0.003%-0.56% (Fischer exact test). Seven patients required further surgery: 3 had graft replacements, and 1 each for recurrence, strabismus, inclusion cyst, and granuloma. One patient lost 4 lines of vision from a corneal ulcer.

CONCLUSIONS

Pterygium extended removal followed by extended conjunctival transplant results in one of the lowest recurrence rates reported in the world's literature and an acceptable complication rate.

Late-onset necrotizing scleritis due to pigmented mycetoma (dematiaceous fungi) in 2 cases

PURPOSE

To describe the atypical presentation of fungal infection and necrotizing scleritis, the potential role of histopathology in the diagnosis, and surgical excision in the management.

METHODS

Retrospective interventional case series.

RESULTS

Two patients presented with a pigmented conjunctival mass, one resembling necrotizing scleritis with uveal prolapse and the other resembling a pigmented ocular surface tumor, both after excision of nasal pterygium, 12 and 50 years previously, respectively. The pigmented lesion was 2 × 1.5 mm in each case, both situated on the bulbar surface 2 mm from the nasal limbus. After surgical excision, each lesion histopathologically displayed fungal filaments (pigmented dematiaceous fungi).

CONCLUSIONS

Pigmented mycetoma (dematiaceous fungi) can simulate uveal tissue prolapse, pigmented foreign body, or pigmented epibulbar tumors, particularly melanoma. Surgical excision of the entire lesion is effective for management.

Corneal melting two weeks after pterygium excision with topical mitomycin C: successfully treated with lamellar keratoplasty and amnion membrane transplantation

Purpose

To report the management of a case of corneal melting two weeks after pterygium excision with intraoperative topical mitomycin C (MMC).

Methods

Case report.

Results

A 57-year-old male was referred to our Department for therapy of rapidly progressive corneal melting two weeks after primary pterygium surgery with MMC (0.2 mg/ml) in September 2009. Initial treatment consisted of topical and systemic immunosuppression along with topical antibiotics. Eight days after presentation, the patient underwent successful lamellar keratoplasty and amnion membrane transplantation. Subconjunctival injection of triamcinolone (40 mg/ml) and topical bevacizumab were used to manage the increased fibrovascular activity around the site of the former pterygium.

Conclusion

Topical use of MMC during pterygium surgery may be related to serious postoperative complications such as progressive inflammatory corneal melting. The etiology may be multifactorial, which is related to MMC-induced inflammation and/or induced apoptosis. A therapeutic option is the described combination of systemic and local anti-inflammatory treatment along with lamellar keratoplasty and amniotic membrane transplantation. Adjunctive therapy may be needed if recurrence occurs.

Intraoperative mitomycin C versus autologous conjunctival autograft in surgery of primary pterygium with four-year follow-up

PURPOSE

To compare the 4-year outcome of primary pterygium excision using intraoperative mitomycin C (MMC) with suturing a free conjunctival autograft (CA).

METHODS

A total of 115 eyes with nasal primary pterygium of 115 patients were included in the study. After randomization into two groups, the eyes were operated on by a single surgeon (GK). After excision of the pterygium, 56 eyes received 0.04% MMC intraoperatively on the bare sclera for 3 min and 59 eyes received a free CA sutured using 7-0 Vicryl. Postoperative follow-up was 4 years. Main outcome measures were recurrences, re-operations, surgery time, complications, visual acuity and astigmatism. Statistical evaluation was performed with the chi-squared test.

RESULTS

The recurrence rate was 38% in the MMC group and 15% in the CA group (p < 0.05). The re-operation rate of the recurrences was 53% in the MMC group and 29% in the CA group. Average surgery time was 13 minutes (range: 6-22 min) in the MMC group and 26 min (range: 18-32 min) in the CA group (p < 0.01). There was no significant change in best-corrected visual acuity and astigmatism. One major complication occurred in each group. The most frequently observed complication was delayed epithelial healing (40%) and mild scleral thinning (20%) in the MMC group and suture-related inflammation in the CA group (10%).

CONCLUSION

Pterygium surgery including free autologous conjunctival grafting is associated with fewer recurrences, re-operations and complications than using the bare sclera technique together with single-dose intraoperative MMC.