Identification and Analysis of Primary Cilia in the Corneal Endothelial Cells of Patients with Bullous Keratopathy.

PURPOSE: To identify primary cilia in human corneal endothelial cells (CECs) obtained from patients with bullous keratopathy (BK). METHODS: This study involved CEC specimens obtained from 10 eyes of 10 consecutive patients (three males and seven females; mean age: 74.5 years, range: 68-90 years) with BK who underwent Descemet's stripping automated endothelial keratoplasty at Baptist Eye Institute, Kyoto, Japan between August 2019 and September 2020. Three corneal buttons obtained from 3 patients who underwent penetrating keratoplasty for keratoconus were used as 'non-BK' controls. All specimens were evaluated with immunofluorescence staining using an antibody against acetylated α-tubulin. RESULTS: Ciliary expression was observed in six of the 10 CEC specimens; i.e. in two specimens obtained from BK patients after glaucoma surgery (trabeculectomy), in two specimens obtained from patients with Fuchs endothelial corneal dystrophy, and in two specimens obtained from a patient with BK after laser iridotomy for primary angle closure. There was acetylated α-tubulin staining but no hair-like structures in two specimens, and ciliary expression was unknown in two specimens due to the absence of cells. The length of the primary cilia varied between all specimens. In contrast, no primary cilia were observed in the corneal buttons obtained from the three keratoconus patients. CONCLUSION: The findings in this study clearly demonstrate the expression of primary cilia in the CECs of patients afflicted with BK.

Strategic combination of cultivated oral mucosal epithelial transplantation and postoperative limbal-rigid contact lens-wear for end-stage ocular surface disease: a retrospective cohort study.

PURPOSE: To provide the long-term outcome of patients with end-stage severe ocular surface disease (OSD) consecutively treated with cultivated oral mucosal epithelial transplantation (COMET) followed by limbal-rigid contact lens (CL)-wear therapy. DESIGN: Retrospective cohort. METHODS: In 23 eyes of 18 patients with severe OSD who underwent COMET surgery between 2002 and 2019 and who were followed with limbal-rigid CL-wear therapy for at least 1 year postoperative, patient demographics, best-corrected visual acuity (BCVA, logMAR), Ocular Surface Grading Scores (OSGS), surgical indication and adverse events were reviewed. Primary and secondary outcomes were BCVA and OSGS changes at baseline and final examination, respectively. RESULTS: This study involved 16 patients with Stevens-Johnson syndrome and 2 patients with mucous membrane pemphigoid (mean age: 59±15 years). The indications for COMET were as follows: corneal reconstruction for vision improvement (10 eyes (43.5%)), corneal reconstruction for persistent epithelial defect (4 eyes (17.4%)) and conjunctival (fornix) reconstruction for symblepharon release (9 eyes (39.1%)). The mean duration of CL-wear postsurgery was 6.4±3.9 years (range: 1.4 to 13.3 years). The mean BCVA at baseline and at final follow-up was logMAR 1.9±0.5 and 1.3±0.7, respectively (p<0.05). Compared with those at baseline, the OSGSs for symblepharon and upper and lower fornix shortening showed significant improvement at each follow-up time point post treatment initiation. No serious intraoperative or postoperative adverse events were observed. CONCLUSION: In patients afflicted with severe OSD, COMET combined with limbal-rigid CL-wear therapy postsurgery was found effective for vision improvement and ocular surface stabilisation.

Limbal-Rigid Contact Lens Wear for the Treatment of Ocular Surface Disorders: A Review.

ABSTRACT: Recently, the prescription of large-diameter rigid gas-permeable contact lenses (CLs), also known as "scleral lenses," "corneoscleral lenses," and "limbal-rigid CLs," is on the rise for the treatment of both moderate and severe ocular surface disorders (OSDs). Compared with scleral lenses, the diameter of limbal-rigid CLs is generally smaller, that is, a diameter ranging from 13.0 to 14.0 mm, and they are designed so that the peripheral edge bears on the limbus. The Suncon Kyoto-CS (Sun Contact Lens Co., Ltd.) is a novel limbal-rigid CL design with multistep curves on the peripheral edge for easy tear exchange during blinking that removes debris and prevents lens clouding or fogging, thus allowing patients to enjoy a longer daily duration of CL wear. In severe OSD cases, limbal-rigid CL wear after surgery is a noninvasive therapeutic approach that can neutralize corneal irregularities, decrease dry eye symptoms, prevent the progression or recurrence of symblepharon, and improve the patient's visual acuity and overall quality of life. Thus, surgeries such as amniotic membrane transplantation and cultivated oral mucosal epithelial transplantation, as well as limbal-rigid CL wear, which is noninvasive, are valuable and effective treatment strategies that can now be applied for the management of patients afflicted with severe OSDs.

Long-term outcome of cultivated oral mucosal epithelial transplantation for fornix reconstruction in chronic cicatrising diseases.

BACKGROUND/AIMS: To investigate the long-term outcomes of cultivated oral mucosal epithelial transplantation (COMET) for fornix reconstruction in eyes with chronic cicatrising disease. METHODS: This retrospective cohort study involved 16 eyes of 15 patients who underwent COMET for symblepharon release and fornix reconstruction between June 2002 and December 2008. The mean postoperative follow-up period was 102.1±46.0 months (range: 32-183 months). The treated cicatrising disorders included ocular cicatricial pemphigoid (OCP, five eyes), thermal/chemical injury (three eyes) and other chronic diseases (seven eyes; including recurrent pterygium (two eyes), Stevens-Johnson syndrome (one eye) and graft-versus-host disease (one eye)). Ocular-surface appearance was evaluated before surgery, at 1, 4, 12 and 24 weeks postoperative, and then annually based on the previously reported scoring system. Main outcome measures included overall and disease-specific fornix-reconstruction success probabilities analysed by the Kaplan-Meier survival curve. Symblepharon/fornix-shortening recurrence at 24 weeks postoperative, and its relationship to long-term surgical success was also examined. RESULTS: At 5 years postoperative, the mean±SD overall fornix-reconstruction success probability was 79.6%±10.7%, and success probability for thermal/chemical injury and OCP was 100% and 53.3%±24.8%, respectively (p=0.53, log-rank test). The 3-year success probability was significantly higher in the no-disease-recurrence group at 24 weeks postoperative (13 eyes) than in the disease-recurrence group (three eyes) (100% and 33.3%±27.2%, respectively) (p=0.0073, log-rank test). CONCLUSION: COMET was found to be safe and effective for symblepharon release and long-term fornix reconstruction in eyes with chronic cicatrisation. Although the 5-year success probability differed depend on the underlying disease, ocular-surface appearance at 24 weeks postoperative is a factor for predicting long-term outcome.

A Case of Black Fungal Keratitis Caused by Biatriospora mackinnonii.

PURPOSE: To report a novel case of fungal keratitis caused by Biatriospora mackinnonii (Pyrenochaeta mackinnonii), a dematiaceous fungus (black fungus) that rarely causes dermatological infection, in a patient treated for ocular cicatricial pemphigoid. METHODS: An 81-year-old patient with ocular cicatricial pemphigoid was referred to our hospital because of persistent corneal epithelial defects in his left eye. On examination, a slightly elevated dark lesion in the middle of the erosion and hypopyon was observed in that eye, with smear examination of the obtained specimen revealed a filamentous fungal-like material. Initially, treatment included miconazole and fluconazole ophthalmic solution eye drops, natamycin ophthalmic ointment, and systemic voriconazole, followed surgical scraping of the mass, an anterior chamber lavage, and a subconjunctival injection of miconazole. However, the focus had resistance to the treatment and finally led to corneal perforation; hence, therapeutic penetrating keratoplasty (PKP) was subsequently performed. RESULTS: Mycological testing revealed that the lesions were Candida parapsiliosis and black fungus, with the black fungus classified as B. mackinnonii via DNA sequencing of the internal transcribed spacer and the D1/D2 domains of the 28S rRNA gene. Fungal keratitis caused by B. mackinnonii was resistant to the antifungal drugs, yet was ameliorated by PKP, with no recurrence of fungal keratitis for more than 2 years postoperative. CONCLUSIONS: To the best of our knowledge, this is the first reported case of fungal keratitis caused by B. mackinnonii; however, in this case, PKP surgery resulted in a favorable outcome.

Oral Mucosal Epithelial Transplantation and Limbal-Rigid Contact Lens: A Therapeutic Modality for the Treatment of Severe Ocular Surface Disorders.

Stevens-Johnson syndrome, ocular cicatricial pemphigoid, and severe thermal or chemical injury are considered severe ocular surface disorders (OSDs) because they affect the entire ocular surface, including corneal and conjunctival epithelial stem cells. In patients with severe OSDs, the long-term prognosis for limbal transplantation is poor, and the related corneal opacity and cicatrization lead to devastating visual impairment. To date, there is no standardized treatment to improve vision in cases with severe OSD. Investigating novel treatment methods for severe OSDs, our group began cultivated oral mucosal epithelial transplantation in 2002 and developed a limbal-supported rigid-type contact lens that can be applied as a nonsurgical treatment. When used in combination, these treatment methods make it possible to successfully restore vision in cases with severe OSDs.

Five-year follow-up outcomes after Descemet's stripping automated endothelial keratoplasty: a retrospective study.

OBJECTIVE: To assess graft survival and endothelial cell density (ECD) over a 5-year follow-up period after Descemet's stripping automated endothelial keratoplasty (DSAEK). METHODS AND ANALYSIS: This retrospective study involved 130 eyes of 130 consecutive patients with Fuchs endothelial corneal dystrophy (FECD), non-FECD bullous keratopathy (BK) (non-FECD) or BK post-trabeculectomy or tube-shunt surgery (glaucoma with bleb) who underwent DSAEK between August 2007 and January 2012 and were followed for more than 5 years postoperatively. Patients with previous keratoplasty, graft suture failure, primary graft failure, postoperative endophthalmitis and ocular infection were excluded. Graft survival and ECD was then examined in all patients who underwent DSAEK and completed the postoperative follow-up period. The association between clinical factors and 5-year graft survival after DSAEK was analysed with multivariate logistic regression analysis. RESULTS: The overall graft survival rate at 5 years postoperatively was 85%, yet significantly poorer in the glaucoma with bleb eyes (47%) than in the FECD (100%) or non-FECD (90%) eyes (p<0.01, log-rank test). In the FECD, non-FECD and glaucoma with bleb eyes, the mean ECD at 5 years postoperatively was 1054 cells/mm2, 1137 cells/mm2 and 756 cells/mm2, respectively. Multivariate logistic regression analysis showed history of trabeculectomy or tube-shunt surgery and postoperative allograft rejection to be negative factors for graft survival at 5 years after DSAEK (OR 0.01, 95% CI 0.00 to 0.10 and OR 0.02, 95% CI 0.00 to 0.33, respectively). CONCLUSION: Our findings show that at 5 years postoperatively, the surgical outcome after DSAEK was poorer in eyes after trabeculectomy or tube-shunt surgery. TRIAL REGISTRATION NUMBER: UMIN000024891.

A novel mutation in gelatinous drop-like corneal dystrophy and functional analysis.

We identified a novel mutation of the tumor-associated calcium signal transducer 2 (TACSTD2) gene in a Japanese patient with gelatinous drop-like corneal dystrophy (GDLD). Genetic analysis revealed a novel homozygous mutation (c.798delG, which may result in frameshift mutation p.Lys267SerfsTer4) in the TACSTD2 gene. This mutated gene was devoid of its original function in helping the claudin (CLDN) 1 and 7 proteins transfer from the cytoplasm to the plasma membrane.

Topical non-steroidal anti-inflammatory drugs for the treatment of cystoid macular edema post Descemet's stripping automated endothelial keratoplasty.

PURPOSE: To investigate the effectiveness of topical non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of cystoid macular edema (CME) post Descemet's stripping automated endothelial keratoplasty (DSAEK). STUDY DESIGN: Retrospective observational study METHODS: In this study of 334 patients who underwent DSAEK at the Baptist Eye Institute, Kyoto, Japan between July 2011 and December 2015, 18 patients with postoperative CME (determined by optical coherence tomography) treated with topical NSAIDs after the onset of CME were included. RESULTS: At CME onset, 17 of the 18 patients were treated with bromfenac eye drops and 1 was treated with nepafenac eye drops. Post initiation of treatment with topical NSAIDs, CME in 17 (94.4%) of the 18 patients improved at 1 month and all cases completely recovered within 3 months. At 12-months post initiation of treatment, 61.1% (n = 11) of patients achieved a visual acuity (VA) of 20/40 or better, and there was no significant difference of VA between the patients with or without an episode of postoperative CME (P = 0.55). CONCLUSION: The administration of topical NSAID eye drops was found to be effective in treating patients with CME post DSAEK.

Moderately Long-Term Safety and Efficacy of Repeat Penetrating Keratoplasty.

PURPOSE: To investigate the moderately long-term safety and efficacy of repeat penetrating keratoplasty (PK) for treatment of a failed PK graft. METHODS: Retrospective consecutive clinical case series. Of 992 consecutive cases that underwent PK at Baptist Eye Institute, Kyoto, Japan, between April 1998 and September 2013, 96 cases that underwent repeat PK with more than 3 years postoperatively follow-up were retrospectively reviewed. Surgical outcomes including donor graft survival rate, best spectacle-corrected visual acuity, endothelial cell density, and complications afeter repeat PK were assessed. RESULTS: At 1, 3, and 5 years after repeat PK, the donor graft survival rate was 91%, 75%, and 64%, respectively, and the mean endothelial cell density in those survived grafts was 1778, 1207, and 989 cells/mm, respectively. Best spectacle-corrected visual acuity over 20/200 and 20/40 was achieved in 71% and 27% of the patients, respectively, at 1 year postoperatively, in 59% and 31% of the patients, respectively, at 3 years postoperatively, and in 53% and 29% of the patients, respectively, at 5 years postoperatively. The most common complication for repeat PK was the need for additional glaucoma surgery [n = 11 patients (11.5%)]. Cox proportional hazard regression analyses revealed that previous glaucoma surgery and a rejection episode were high risk factors for graft failure in repeat PK [hazard ratio (HR) = 6.7; 95% confidence interval (CI), 2.1-21.2 and HR = 5.6; 95% CI, 1.8-18.0, respectively]. CONCLUSIONS: Repeat PK provided relatively safe and effective moderately long-term surgical outcomes.

Predictive clinical factors of cystoid macular edema in patients with Descemet's stripping automated endothelial keratoplasty.

The purpose of this present study was to investigate predictive clinical factors associated with cystoid macular edema (CME) post Descemet's stripping automated endothelial keratoplasty (DSAEK) in a large case series. Of 393 consecutive patients who underwent DSAEK at Baptist Eye Institute, Kyoto, Japan between July 2011 and November 2016, 241 patients without CME at the pre- or early-postoperative periods were enrolled. The occurrence of anatomic CME was prospectively examined via optical coherence tomography (OCT). Possible predictive clinical factors for CME were analyzed by multivariate logistic regression analysis. At 1-month post DSAEK, CME occurred in 27 (11.2%) of the 241 patients. Multivariate analysis revealed that primary angle closure glaucoma (PACG) was significantly associated with postoperative CME (odds ratio = 6.4, P = 0.04). The findings of this study revealed that DSAEK in patients with PACG showed a high incidence of CME, thus indicating that they should undergo a careful postoperative observation of the macula via OCT.

Safety of anterior chamber paracentesis using a 30-gauge needle integrated with a specially designed disposable pipette.

AIMS: To investigate the safety of anterior chamber (AC) paracentesis using a 30-gauge needle integrated with a specially designed disposable pipette. METHODS: In this retrospective observational case-series study, AC paracentesis was performed on 301 eyes of 301 patients between September 2009 and August 2016 at the Department of Ophthalmology, Kyoto Prefectural University of Medicine and the Baptist Eye Institute, Kyoto, Japan. AC paracentesis was performed with the patient placed in the supine position using a 30-gauge needle integrated with a disposable pipette with one hand, and the safety post procedure was then evaluated. RESULTS: The indications for AC paracentesis were virus detection (ie, corneal endotheliitis, anterior infectious uveitis, cytomegalovirus retinitis and acute retinal necrosis) in 264 eyes, bacterial detection (ie, endophthalmitis) in 8 eyes and malignancy (ie, primary intraocular lymphoma, leukaemia and retinoblastoma) in 29 eyes. No serious complications such as infection, hyphema, lens trauma or severe inflammation including hypopyon and AC fibrin formation were observed. CONCLUSIONS: Our findings show that AC paracentesis with a disposable pipette is safe with no severe complications.

Development of functional human oral mucosal epithelial stem/progenitor cell sheets using a feeder-free and serum-free culture system for ocular surface reconstruction.

Ocular surface reconstruction (OSR) using tissue-engineered cultivated oral mucosal epithelial cell sheets (COMECS) is a promising newly developed treatment for patients with severe ocular surface disease. Until now, this technique has used exogenic and undefined components such as mouse-derived 3T3 feeder cells and fetal bovine serum. To minimize associated risks of zoonotic infection or transmission of unknown pathogens and so establish a safe and effective protocol for the next generation of treatment modality, we developed a novel technique for the COMECS protocol, using a feeder-free and serum-free (FFSF) culture system. Following this new protocol, COMECS exhibited 4-5 layers of well-stratified and differentiated cells, and we successfully produced functional COMECS that included holoclone-type stem cells. Immunohistochemistry confirmed the presence of markers for cell junction (ZO1, Desmoplakin), basement membrane assembly (Collagen 7, Laminin 5), differentiation (K13, K3), proliferation (Ki67) and stem/progenitor cells (p75) in the FFSF COMECS. When transplanted to the ocular surfaces of rabbits, the tissue survived for up to 2 weeks. This study represents a first step toward assessing the development of functional FFSF COMECS for safe and ideal OSR.

Boston Type 1 Keratoprosthesis for Gelatinous Drop-Like Corneal Dystrophy.

PURPOSE: To report the outcomes of Boston type 1 keratoprosthesis in the management of advanced gelatinous drop-like corneal dystrophy (GDLD). METHODS: A retrospective, noncomparative, interventional case series was conducted at Ramathibodi Hospital, Bangkok, Thailand. Four eyes of three siblings with molecularly and histologically confirmed GDLD from a Thai family underwent an uneventful Boston type 1 keratoprosthesis implantation for visual rehabilitation. Clinical data were obtained from a review of the medical records. Visual acuity, device retention, and postoperative complications were the main outcome measures. The follow-up ranged from 8 to 96 months. RESULTS: One eye received keratoprosthesis surgery as a primary penetrating procedure. The other three eyes had the surgery as a secondary procedure after graft failure. Best-corrected visual acuity was favorably improved from counting fingers to 20/25 in two eyes, from hand movement to 20/20 in one eye, and from hand movement to counting fingers at 2 feet in one eye caused by severe amblyopia. The improved vision was maintained for 8 months to 6.2 years after surgery. Postoperative complications included disease recurrence in the donor graft (N = 3), manageable retroprosthetic membrane (N = 3), intraocular pressure elevation responded to antiglaucoma drugs (N = 2), and Pseudomonas keratitis with severe corneal melting requiring device removal (N = 1). All of our patients failed to have a comfortably well-fitting contact lens after surgery. CONCLUSIONS: Boston type 1 keratoprosthesis could be considered as a reasonable option in the management of advanced GDLD. However, patients remain at risk for sight-threatening postoperative complications as long as the keratoprosthesis is retained. The use of Boston keratoprosthesis implantation needed to be individualized on a case-by-case basis.

Elevated expression of ABCB5 in ocular surface squamous neoplasia.

ATP-binding cassette subfamily B member 5 (ABCB5) is a new member of the ATP-binding cassette superfamily and has been reported as a novel marker for limbal stem cell (LSC), which is essential for corneal homeostasis. ABCB5 expression has also been discovered in the subpopulation of several cancer cells containing the cancer stem cell (CSC). However, the pathogenetic relationship between LSC and CSC and ABCB5 in the ocular surface squamous neoplasm (OSSN) is still entirely unknown. To improve understanding of the role of ABCB5 in OSSN, we performed immunohistochemistry for ABCB5 in nine OSSN case series. While expression of ABCB5 is restricted to the basal epithelial cell layer in the normal limbus, elevated expressions of ABCB5 were clearly observed in all OSSN, and there was some breadth in the range of intensity of ABCB5 expression. Interestingly, the elevated expression patterns of ABCB5 in OSSN could be classified in three categories: perivascular, marginal and diffuse patterns. Our findings demonstrated for the first time that the expression of ABCB5 was upregulated in OSSN and that elevated expression of ABCB5 may be involved in the pathogenesis of OSSN.

Ocular surface reconstruction using stem cell and tissue engineering.

Most human sensory information is gained through eyesight, and integrity of the ocular surface, including cornea and conjunctiva, is known to be indispensable for good vision. It is believed that severe damage to corneal epithelial stem cells results in devastating ocular surface disease, and many researchers and scientists have tried to reconstruct the ocular surface using medical and surgical approaches. Ocular surface reconstruction via regenerative therapy is a newly developed medical field that promises to be the next generation of therapeutic modalities, based on the use of tissue-specific stem cells to generate biological substitutes and improve tissue functions. The accomplishment of these objectives depends on three key factors: stem cells, which have highly proliferative capacities and longevities; the substrates determining the environmental niche; and growth factors that support them appropriately. This manuscript describes the diligent development of ocular surface reconstruction using tissue engineering techniques, both past and present, and discusses and validates their future use for regenerative therapy in this field.

Phenotypic Investigation of Regenerated Epithelial Cells After Gonococcal Corneal Perforation: A Clinical, Histological, and Immunohistochemical Study.

PURPOSE: To determine the characteristics of regenerated epithelial cells after severe gonococcal infection after corneal perforation. METHODS: Pathological tissue was obtained from the cornea at the time of surgery. Hematoxylin and eosin staining and immunohistochemical analysis were performed for cytoskeletal keratins (K12, K13, and K15), basement membrane and junctional markers (laminin 5, ZO-1 and Desmoplakin), and proliferative and mesenchymal markers (Ki67, α-SMA, and vimentin). RESULTS: A 42-year-old patient with severe gonococcal keratoconjunctivitis rapidly progressed to corneal perforation during administration of intensive topical and systemic antibiotics. After conservative treatment, the perforation healed and 5- × 3-mm corneal ectasia occurred with localized iris attachment. Complete closure of the cornea was confirmed by a negative Seidel test. After lamellar keratoplasty to improve corneal integrity and to prevent secondary glaucoma, the pathological tissue revealed a poorly organized epithelial layer at the regenerated ectatic area. The regenerated epithelial cells clearly expressed K12, ZO-1, and Desmoplakin with underlying laminin 5 (+) basement membrane. K15 and Ki67 expressions were observed predominantly at the limbal area but not in the regenerated area. α-SMA and vimentin were sporadically expressed in the underlying connective tissue. CONCLUSIONS: We speculate that the process of epithelial wound healing at the site of corneal perforation was responsible for migration of the surrounding epithelial cells. Although the regenerated cells expressed several cytokeratins and junctional markers, they remained disorganized and fragile.

Upregulation of Toll-like receptor 5 expression in the conjunctival epithelium of various human ocular surface diseases.

AIMS: To examine the expression of Toll-like receptor (TLR) 5 in the conjunctival epithelium of patients with severe ocular surface diseases. METHODS: Immunohistochemical study of TLR5 was performed on conjunctival tissues obtained from patients undergoing surgical reconstruction of the ocular surface to treat Stevens-Johnson syndrome (SJS) (n=4), ocular cicatricial pemphigoid (OCP) (n=3), chemical eye burn (n=3), and pterygium (n=2), and on nearly normal conjunctival tissues obtained during surgery for four cases of conjunctivochalasis as a control. RESULTS: TLR5 protein was consistently and abundantly expressed in the conjunctival epithelium and detected only at the basal and wing cells. However, in the conjunctival epithelium obtained from the patients with SJS, OCP and chemical eye burns, the TLR5 protein was detected at not only the basal and wing cells but also at the superficial cells. TLR5 protein detected in the pterygium patients mirrored that detected in the controls. CONCLUSIONS: Although TLR5 was normally present on the basal and wing cells of conjunctival epithelium with spatially selective presence, it was expressed on not only the basal and wing cells but also the superficial cells in the conjunctival epithelium of patients with SJS, OCP or chemical eye burns, suggesting that TLR5 might be upregulated in the conjunctival epithelium of these diseases.

Cultivated oral mucosal epithelial transplantation for persistent epithelial defect in severe ocular surface diseases with acute inflammatory activity.

PURPOSE: To assess the clinical efficacy of cultivated oral mucosal epithelial transplantation (COMET) for the treatment of persistent epithelial defect (PED). METHODS: We treated 10 eyes of nine patients with PED (Stevens-Johnson syndrome: three eyes; thermal/chemical injury: five eyes; ocular cicatricial pemphigoid: two eyes) with COMET at Kyoto Prefectural University of Medicine, Kyoto, Japan from 2002 to 2008. RESULTS: Preoperatively, PED existed on over more than 50% of the corneal surface in seven eyes. Severe ocular surface inflammation with fibrovascular tissue surrounded the PED in all 10 eyes. At 24-weeks postoperative, PED had improved in all cases except 1 in which the patient was unable to return to the hospital (95% CI, 55.5-99.7; Wilcoxon signed-rank test, p = 0.0078). The preoperative median of logarithmic minimum angle of resolution was 1.85 (range 0.15-2.70), and 1.85, 1.85, and 1.52 at the 4th, 12th, and 24th postoperative week, respectively. The mean total preoperative ocular surface grading score was 7.0 (range 4-17). At 4 and 12 weeks postoperative, the total ocular surface grading score had improved significantly (p = 0.0020, p = 0.0078), and at 24 weeks postoperative, it was 3.0 (range 2-12, p = 0.0234). During the follow-up period (median 23.3 months, range 5.6-39.7 months), no recurrence of PED was observed in any eye, and long-term ocular surface stability was obtained. CONCLUSION: COMET enabled complete epithelialization of PED and stabilization of the ocular surface in patients with severe ocular surface disease, thus preventing end-stage cicatrization and vision loss at a later stage.