Superficial Lamellar Keratectomy Research Articles

Low-dose intravitreal injection of 4 mg preservative-free gentamicin and superficial lamellar keratectomy combined with modified Gundersen grafts to control chronic heterochromic iridocyclitis and secondary keratitis in horses.

To describe a combined treatment approach for heterochromic iridocyclitis and secondary keratitis (HIK) in horses. A total of 15 horses (16 eyes). Sixteen eyes from 15 horses (mean age 14.1 years, range 6-26 years) received low-dose (4 mg) intravitreal preservative-free gentamicin injection (IVGI) and modified Gundersen grafts with standing sedation and local anesthesia following a clinical diagnosis of HIK. Additional therapies of suprachoroidal triamcinolone (8 mg) injection, episcleral bromfenac implants, and suprachoroidal cyclosporine implants were performed in individual cases. Leptospira titers were also reported when available. The most frequent ophthalmic findings were pigmented keratic precipitates (n = 15/16 eyes, 94%), corneal edema (n = 14/16 eyes, 88%), and pigmented cells suspended in the anterior chamber (n = 7/16 eyes, 44%). Postoperative treatment generally consisted of topical and systemic NSAIDs, topical antibiotics, and a topical mydriatic agent. Complications included persistent corneal edema (7/16, 44%), corneal ulceration (6/16, 38%), graft failure requiring revision (2/16, 13%), stromal abscess (1/16, 6%), surgery site infection (1/16, 6%), and suspected retinal degeneration following IVGI (1/16, 6%). One case was enucleated 6 months after treatment (1/16, 6%). Of the 12 eyes with at least 3 months of post-treatment follow-up, 10 were comfortable and visual with static or improved symptoms of HIK. This multimodal treatment approach aims to address both the anterior uveitis and endothelial decompensation frequently seen in horses with HIK. The surgery can be performed under standing sedation. Continued evaluation and long-term follow-up is necessary in all horses with HIK.

Corneal Neuro-Regenerative Effect of Transcutaneous Electrical Stimulation in Rabbit Lamellar Keratectomy Model.

PurposeThis study aimed to evaluate the effect of transcutaneous electrical stimulation (TES) on corneal nerve regeneration in rabbits injured from superficial lamellar keratectomy (SLK).MethodsNew Zealand White rabbits were used in this experimental study. To induce corneal nerve damage, SLK was performed using a 7.0-mm trephine. TES was applied for 28 days after the corneal nerve injury. Corneal sensitivity, Western blotting, real-time polymerase chain reaction (PCR), and immunofluorescence were performed to observe changes in the corneal tissue.ResultsIn the 2-Hz and 20-Hz electrical stimulation groups, the degree of corneal wound healing increased by more than 10% compared to the control group, but no significant difference was observed. Conversely, the electrical stimulation (2-Hz or 20-Hz) group showed significantly increased corneal sensitivity compared to the control group. Western blot analysis revealed that small proline-rich protein 1A (SPRR1a), a regeneration-associated protein was significantly increased in the 2-Hz group on days 1 and 7 compared to that in the other groups. Once again, nerve regeneration in the 2-Hz group was supported by the results of PCR, in which a significant increase in the nerve growth factor (NGF) on day 1 was observed compared with the other groups. Moreover, immunofluorescence after 28 days of electrical stimulation showed significant nerve regeneration in the 2-Hz group.ConclusionsTES promoted corneal nerve regeneration in rabbit SLK model. The application of electrical stimulation of 2-Hz frequency was more effective than the 20-Hz frequency, showing potential clinical applications for corneal diseases.Translational RelevanceThis study shows how application of TES to the eyes that exhibit corneal nerve damage can improve corneal nerve regeneration examined by histologic analysis.

Corneal diamond burr debridement for superficial non‐healing corneal ulcers in cats

To describe the clinical outcomes and efficacy of diamond burr debridement (DBD) treatment for corneal ulceration in cats. Medical records of cats that received DBD at two private practices between 2015 and 2021 were retrospectively reviewed. DBD was performed using a battery-powered, handheld motorized burr and a bandage contact lens was placed in 18/21 eyes. Corneal ulceration was considered resolved if the cornea was fluorescein negative with a stable epithelial surface. Recurrence was defined as return of corneal ulceration. Descriptive statistics and a Fisher's exact test were conducted on the study population. Twenty-one eyes from 20 cats with superficial corneal ulcers refractory to medical treatment underwent DBD. Domestic and Burmese were the most commonly encountered breeds and the median age of affected cats was 8.83 years (range 0.5-20 years). Corneal ulceration was present for a median of 14 days prior to DBD. Healing was achieved in 81% of eyes; with four eyes failing to heal and requiring further intervention. Corneal sequestrum was reported in one case that failed to heal. Of the healed cases, three cases recurred (17.6%) at a mean of 116.3 days (range 79-135 days). Burmese were overrepresented (p< .001) in cases that failed to heal or recurred (6/7 eyes; 85.7%). The median postoperative follow-up time was 93 days (range 6-1613 days). Diamond burr debridement is a safe, non-invasive treatment for corneal ulceration in cats but, compared with published results, it had a lower success rate than superficial lamellar keratectomy.

Femtosecond laser assisted superficial lamellar keratectomy as a successful treatment of corneal opacity in a patient with Thiel Behnke corneal dystrophy

Introduction and importanceThiel Behnke corneal dystrophy (TBCD) and Reis Buckler corneal dystrophy (RBCD) are Bowman's layer dystrophies with overlapping clinical features causing diagnostic confusion. However, each entity has typical histopathological features. We describe in this case the successful use of Femtosecond laser (FSL) in the treatment of TBCD-related corneal opacity.Case presentationWe present a 54-year-old male with bilateral superficial corneal opacities consistent with TBCD based on clinical appearance, anterior segment optical coherence tomography (AS-OCT), and In vivo confocal microscopy. Management options were discussed with the patient before proceeding with Femtosecond Laser Assisted Superficial Lamellar Keratectomy (FSLASLK). The histopathological findings of the excised left anterior lamellar corneal flap were typical of TBCD and the patient had a satisfactory outcome.Clinical discussionTBCD typically affects Bowman's layer centrally with progressive opacities involving the deeper layer of the corneal stroma and the periphery with advancing age. Histopathology typically shows subepithelial fibrosis with interrupted basement membrane and totally replaced Bowman's layer by uneven fibrous tissue forming the characteristic saw tooth pattern. The treatment of such cases is challenging with variable success and recurrence rates. Our case was managed successfully using FSL.ConclusionTBCD, even though a rare type of dystrophy, should be suspected based on the appearance of the corneal opacities clinically. It can be diagnosed by typical AS-OCT findings supported by histopathological confirmation and can be successfully treated by FSASLK.

Surgical treatment of limbal dermoid: Reports of cases

Ocular dermoid occur in an unusual and sporadic manner, being considered a congenital alteration, characterized by the presence of tissue of ectopic origin in ocular structures. They can develop in several places, including eyelids, conjunctiva, cornea and nictitating membrane. The objective was to report the cases of two dogs referred to the specialized service of veterinary ophthalmology, presenting tearing and ocular secretion secondary to the dermoid in the temporal limbus region, with extension to the cornea or conjunctiva. The dermoid were surgically treated by resection through conjunctivectomy combined with superficial lamellar keratectomy and corneal polishing with a diamond burr. Surgical excision of dermoid was curative.

Utilização do flap de Gundersen para tratamento de disfunção endotelial em equino – relato de caso

Endothelial dysfunction in horses is associated with dystrophy or degeneration of corneal endothelial cells, clinically presented as a diffuse corneal edema unresponsive to conventional treatments. The main causes of such injury are trauma, ulcerative keratitis, recurrent uveitis, anterior lens dislocation and glaucoma. This paper aims to report a case of endothelial dysfunction in a mare, diagnosed with endothelial dysfunction after uveitis, glaucoma and indolent corneal ulcer. For correction, a superficial lamellar keratectomy followed by permanent conjunctival graft, described as a Gundersen flap, was performed. After intensive eye care, he returned to his athletic functions, maintained corneal and visual axis transparency and ocular reflexes.

Corneal Pyogenic Granuloma Secondary to Toxic Epidermal Necrolysis Syndrome

A 30–year man was referred to our institution for progressive bilateral keratoconjunctivitis following toxic epidermal necrolysis. Slit-lamp examination showed an elevated, red, vascularized lesion covering the entire cornea. The lesion was removed by superficial lamellar keratectomy. The histopathological findings confirmed the diagnosis of corneal pyogenic granuloma. These uncommon lesions usually develop in adults after minor trauma or surgery. To our knowledge, this is the first reported case of corneal pyogenic granuloma related to toxic epidermal necrolysis.

Corneal squamous cell carcinoma in a dog

Background: Squamous cell carcinoma (SCC) is a neoplastic disease of the squamous epithelial cells that has been rarely described in the literature. This neoplasm affects the eyelid, conjunctiva and third eyelid, as well as the cornea. Corneal SCC is a neoplastic lesion characterized by a pink, typically irregular mass protruding from the epithelial surface of the cornea. Canine corneal SCC has been associated with chronic keratoconjunctivitis sicca, or keratitis secondary to exophthalmia and is common in humans, horses and cows. The treatment is surgical with excision of the lesion of the ocular surface. This paper reported a study of a dog with corneal SCC, which was successfully treated with a superficial lamellar keratectomy excision combined with cryosurgery. Case: An 8-year-old male English bulldog was presented for the evaluation of a red mass on its left eye that had progressively grown over a 1-year period. The mass was approximately 6mm in diameter and it was elevated from 3 to 4 mm above the corneal surface with no expansion onto bulbar conjunctiva. At physical examination it was normal except for the ocular disease. A complete blood cell count and serum chemical profiles were unremarkable. The radiographic evaluation did not demonstrate any evidence of metastasis. The mass was excised by a superficial lamellar keratectomy and the surgical bed was frozen with nitrous oxide. The surgical procedures consisted in excising a rim of grossly normal conjunctiva with 2mm along the mass that was sent for histopathological examination. The postoperative measures included the administration of topical tobramycin at 0.3%, four times a day, and systemic carprofen 4 mg/kg, daily, for 5 days. A reexamination was performed after 14, 21, 30, 42, 70 and 180 days postoperatively. When the cornea was healed, topical dexamethasone at 1% was prescribed, twice a day for 2 weeks to control an excessive vascularization at the limbus. In 70 days, the postoperative result was very satisfactory and there was no evidence of ocular inflammation. Two years after the surgical procedure the dog had not developed metastasis or recorrence of the ocular neoplasm. Discussion: Ocular or adnexal SCC in animals and humans is suspected to be a result of the chronic effect of ultraviolet light on the epithelium. Also, in dogs the SCC has been associated with a chronic source of irritation. The dog observed in our study was brachycephalic, with natural exophthalmic eyes and oversized palpebral fissures that may have caused excessive and chronic corneal exposure to solar radiation. The treatment of choice was excision of the lesion with a wide surgical margin, because it is the standard treatment for SCC of the cornea and cryotherapy has been a common modality of treatment. A histological examination revealed islands and nests of pleomorphic epithelial cells and keratin pearls and the diagnosis of the corneal SCC was made. No evidence of metastasis or recurrence has been found since the surgical procedure. Although, recurrence rates following the excision of this neoplasm of the ocular surface ranged an average of 30%. The treatment of the neoplasm was successful in both procedures, once no visible evidence of regrowth presented two years after the keratectomy. Despite being a rare entity, squamous cell carcinoma of cornea should be considered as differential diagnosis in dogs with any corneal mass.

Effective hands-on treatment of a corneal dermoid in a calf

In the present report, an effective hands-on treatment for a corneal dermoid that extended to the third eyelid, in the left eye of a Japanese Black calf is described. Xylazine sedation and local infiltration anesthesia with 2% lidocaine on the upper and lower eyelids as well as the third eyelid, in combination with topical anesthesia was performed. A Weitlaner retractor allowed immobilizing the patient’s eyeball during surgery, and superficial lamellar keratectomy was performed to surgically excise the mass. A temporary tarsorrhaphy was placed in order to allow the surgical corneal wound to heal as well as to treat keratitis. After an uneventful postoperative recovery, complete cure 70 days post-operatively was achived. This hands-on method represents a practical and effective treatment for ocular dermoids in calves.

Long-Term Follow-Up of Amniotic Membrane Graft for the Treatment of Symblepharon in a Patient With Recessive Dystrophic Epidermolysis Bullosa

To report a case of symblepharon due to epidermolysis bullosa (EB), surgical treatment, and follow-up to 14 years. A 17-year-old white female with recessive dystrophic EB presented with decreased vision due to extensive symblepharon OU. There was opacification and neovascularization of the cornea OU with limited motility. The symblepharon was surgically lysed, anterior lamellar keratectomy performed, and amniotic membrane graft transplanted to the cornea and palpebral conjunctiva, first in the OS and subsequently in the OD. Visual acuity improved from counting fingers to 20/40 in the OS and from 20/200 to 20/70 in the OD at 2 months and 6 weeks postoperatively, respectively, with minimal symblepharon, mild corneal scarring, neovascularization, and haze of OU. She recovered full ductions, but noted diplopia and had a 35 prism diopter exotropia. Symblepharon resolved after 6 months, and alignment improved to 4 prism diopter exophoria. At 14 years follow-up, visual acuity was 20/20 in the OD and 20/30 in the OS, with clear cornea, maintained on fluorometholone 0.1% one drop OU at bedtime. Surgical symblepharolysis, superficial lamellar keratectomy, and amniotic membrane graft transplantation were effective for our patient with recessive dystrophic EB. Her postoperative exotropia resolved over time with monitoring and convergence exercises.

Continuous ophthalmic treatment using an osmotic pump in a bull calf following surgical removal of an ocular dermoid: a case report

An intact male, six-month-old Hanwoo bull calf (native Korean beef breed) was presented to the Animal Medical Centre, Chonbuk National University because the owner had noticed a conjunctival and corneal abnormality in the left eye (OS). On ophthalmic examination, a small, elevated and skin-like mass lesion, containing hair was found on the ventronasal cornea and the conjunctiva of the third eyelid. In the light of its characteristic appearance, the lesion was classified clinically as a corneal dermoid. Under general anaesthesia, superficial lamellar keratectomy and conjunctivectomy was performed to remove the abnormal tissue. As the owner could not apply topical medications regularly, a drug-filled osmotic pump (Alzet; Alza, Palo Alto, CA) was implanted subconjunctivally under the upper eyelid and connected to a catheter at the lateral limbus. The catheter was fixed to the conjunctiva with 3-0 polyglactin 910 (Vicryl®; Ethicon, Johnson and Johnson, Somerville, USA) and a partial temporary tarsorrhaphy was placed. In order to determine the efficacy of medication delivery, a sample of aqueous humour was collected via aqueocentesis from the anterior chamber at two weeks and four weeks after implantation of the pump. The presence and concentration of ciprofloxacin was determined via mass spectroscopy. Aqueous concentration of ciprofloxacin was 0.093 µg/ml at two weeks and 0.107 µg/ml at four weeks. The calf healed without incident and returned to normal function six weeks following the procedure.

Superficial keratectomy for chronic corneal ulcers refractory to medical treatment in 36 cats

To review the outcome of a case series in which superficial keratectomy was used as a treatment for chronic corneal ulceration. Retrospective study Thirty-six cats (41 eyes) with ulcerative keratitis. Forty-one superficial lamellar keratectomies were performed. Thirty-two and a half percent (32.5%) of the ulcers were resolved within 2 weeks and 85% within 4 weeks after surgery. Nonhealing surgical cases after 4 weeks (13% of the eyes) resolved with prolonged postoperative medical treatment. The mean time to healing was 22.1 days (range 7-74 days). At the end of the follow-up period (mean 8.9 months, range 1-36 months), 82.5% of eyes had regained very good to excellent corneal transparency. Nine cases relapsed (21.9% of the eyes) after surgery. Of those cases, the cornea of eight cats healed after undergoing medical treatment, and one underwent a second limited superficial lamellar keratectomy. Superficial keratectomy in cats is an effective treatment to resolve chronic ulcerative keratitis refractory to medical treatment.

Cosmetic Shell Fitting Over a Sensitive Cornea in Mild Phthisis Bulbi Using Total Conjunctival Flap

Cosmetic scleral shells provide a superior alternative to enucleation or evisceration in the setting of phthisis bulbi. However, corneal irritation often minimizes the wearing time of a scleral shell. This study aimed to evaluate the clinical effectiveness of a total conjunctival flap covering in the management of mild phthisis bulbi with a sensitive cornea. The surgical technique involved a total conjunctival flap covering combined with superficial lamellar keratectomy to allow the fitting of a cosmetic scleral shell over a sensitive cornea. The records of patients with mild phthisis bulbi who underwent this technique from September 2003 through July 2011 were reviewed. Postoperative and long-term complications were noted. Outcome measures included cosmetic appearance, complications, and patient satisfaction. A total of 58 patients (58 eyes) were identified. The mean age at surgery was 28.5 years (range=2-65 years) and the mean follow-up period (follow-up rate=66%) was 42.6 months (range=6-98 months). Postoperative complications like epithelial inclusion cyst (one eye), intolerance of scleral shell wear (2 eyes), and deterioration of phthisis bulbi (3 eyes) were observed during the follow-up interval. Surgical success was achieved in 52 subjects (90%) with the desired prosthetic appearance and motility and no further intervention was required. The total conjunctival flap is an easy and effective globe-conserving alternative to enucleation or evisceration in the cosmetic rehabilitation of patients with mild phthisis bulbi. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Treatment of dematiaceous fungal keratitis in a dog

A 9-year-old castrated male Bichon Frise was evaluated because of a 3-week history of a nonhealing corneal ulcer and corneal pigmentation of the left eye. Ophthalmic examination of the left eye revealed conjunctival hyperemia, corneal neovascularization, corneal edema, corneal ulceration, and central corneal pigmentation. Intraocular structures of the left eye could not be visually examined because of the diffuse nature of the corneal lesions. The right eye had anterior cortical incipient cataracts, nuclear sclerosis, and an inactive chorioretinal scar. Superficial lamellar keratectomy of the left eye was performed for both therapeutic and diagnostic purposes. Histologic evaluation of corneal biopsy specimens revealed dematiaceous fungal keratitis of the left eye, and topical administration of voriconazole was used to successfully resolve the keratitis. Seven months after diagnosis of dematiaceous fungal keratitis, the dog had no clinical signs or history of recurrence of the keratitis. Dematiaceous fungal keratitis should be considered as a possible cause of nonhealing corneal ulceration with heavy pigment deposition in dogs. Results suggested that lamellar keratectomy along with topical administration of voriconazole can be used successfully to treat dematiaceous fungal keratitis in dogs.

Carbon dioxide laser photoablation adjunctive therapy following superficial lamellar keratectomy and bulbar conjunctivectomy for the treatment of corneolimbal squamous cell carcinoma in horses: a review of 24 cases

To determine the complications and nonrecurrence rates following superficial lamellar keratectomy, bulbar conjunctivectomy, and adjunctive carbon dioxide (CO(2)) photoablation for corneolimbal squamous cell carcinoma (SCC) in the horse. Retrospective study. Sample population Twenty-four horses with corneolimbal SCC. Medical records of horses diagnosed with corneolimbal SCC that was surgically excised and where CO(2) photoablation was used as an adjunctive therapy from 2000 to 2007 were reviewed. Signalment, prior therapy, tumor location and size, complications, and recurrence of SCC were recorded. The Thoroughbred was the most commonly (25%) represented breed. Lesions were >10 mm in diameter in 70.8% of cases. Eight horses (33.3%) had neoplastic cells extending to the deep margin of the keratectomy. All horses were available for follow-up for an average ± standard deviation of 40.7 ± 25 months. Four horses (16.7%) developed a recurrence of SCC. Three of these four horses underwent repeat keratectomy and CO(2) photoablation, one each, at 4 months, 1, and 2 years following the initial procedure. One horse underwent enucleation 8 months following the initial procedure. As an adjunctive therapy, CO(2) photoablation was successful in 87.5% of the horses following a single procedure and in a total of 91.7% following a second therapeutic application. CO(2) photoablation appears to be effective as an adjunctive therapy following removal of large corneolimbal SCC in the horse and in cases in which all tumor cells were not excised.

TGFBI-linked corneal dystrophies treated using superficial lamellar keratectomy combined with phototherapeutic keratectomy

TGFBI -linked corneal dystrophies treated using superficial lamellar keratectomy combined with phototherapeutic keratectomy

Femtosecond Laser–Assisted Superficial Lamellar Keratectomy for the Treatment of Superficial Corneal Leukomas

To determine if superficial lamellar corneal excision with femtosecond laser followed by phototherapeutic keratectomy (PTK) using a masking substance improves visual acuity and optical quality of patients with severe corneal opacities. Twelve eyes with corneal haze or scarring underwent confocal microscopy to estimate the opacities' thickness and calculate the excision depth. Femtosecond laser was then used to create a superficial corneal flap. PTK and smoothening with masking substance (0.25% sodium hyaluronate) were done to improve corneal regularity and decrease corneal scarring. Follow-up was performed at 1, 6, and 12 months. Mean logarithm of the minimum angle of resolution of best spectacle-corrected visual acuity improved from 0.62 (mean decimal 0.26) to 0.30 (mean decimal 0.58) at 1 year (P = 0.035). Haze grades improved significantly. Coma-like aberration decreased postoperatively. Results showed that superficial corneal excision with femtosecond laser augmented with PTK laser smoothening assisted with 0.25% sodium hyaluronate improved visual acuity and could be considered as an alternative to more invasive procedures in patients with severe corneal opacities.

Radiotherapy for canine chronic superficial keratitis using soft X-rays (15 kV)

To evaluate the effect of soft X-ray therapy in the treatment of refractory chronic superficial keratitis (CSK). Thirteen dogs with severe CSK, that had been refractory to prior medical and/or surgical therapy were treated with soft X-ray therapy. Both corneas of each dog were irradiated with soft X-rays (15 kV), to a total dose of 30 Gy, administered as two fractions over 48-96 h. Treatment was carried out under deep sedation in all dogs. Three dogs were treated by superficial lamellar keratectomy 48 h prior to radiotherapy. Changes in the extent of corneal pigmentation, pigment density and corneal vascularization were documented using a semi-quantitative grading scheme, schematic drawings and clinical photographs. Only minor, transient adverse effects of treatment, such as photophobia, epiphora and blepharitis were noted. Overall the effect of soft X-rays on the course of the keratitis was superior when compared to the effect of Sr-90 irradiation that had been determined in a previous study. Soft X-ray irradiation combined with keratectomy is a safe and effective new treatment option for severe and advanced CSK with significant visual impairment due to corneal pathology.

Ocular Manifestations and Histologic Characteristics of Keratitis-Ichthyosis-Deafness (KID) Syndrome

Purpose: Keratitis-ichthyosis-deafness (KID) syndrome is a congenital ectodermal disorder presenting the triad of vascularizing keratitis, erythrokeratoderma, and sensorineural deafness. Ocular manifestations such as hyperkeratinization of the eyelids, loss of eyelashes, keratoconjunctivitis sicca, corneal erosions, ulceration, neovascularization, and scarring opacity may be absent or mild, but if present and severe, they can lead to major visual loss. We report a patient with KID syndrome with severe ocular manifestations and the histologic characteristics of a corneal lesion. Case summary: A 5-year-old boy was referred to the Ophthalmology Department for bilateral hyperkeratinization of eyelids, bare eyelashes, and corneal opacity. He showed hyperkeratotic skin lesions and sensorineural hearing loss. Molecular analysis showed a mutation in the GJB2 gene and confirmed the diagnosis of KID syndrome. Initial conservative treatment did not preserve ocular surface integrity, and instead it was maintained by surgical procedures including superficial lamellar keratectomy with amniotic membrane transplantation. The histologic characteristics of corneal lesions are abnormal epithelial differentiation, absence of connexin 26 expression, and partial destruction of the basement membrane.

Amniotic membrane transplantation for corneal surface reconstruction after excision of corneolimbal squamous cell carcinomas in nine horses

The purpose of this study was to evaluate the usefulness and effectiveness of permanent amniotic membrane transplantation as an adjunctive treatment to superficial keratectomy alone or combined with strontium-90 irradiation for treatment of equine corneolimbal squamous cell carcinoma (SCC) to decrease corneal scarring and recurrence rate. The retrospective case study included 11 horses (n = 12 eyes) diagnosed and treated for ocular SCC that involved the limbus and cornea. Nine of those horses (n = 9 eyes) were treated between 2002 and 2006, with superficial lamellar keratectomy alone or combined with strontium-90 irradiation and followed by placement of a permanent amniotic membrane graft in the surgical defect. The level of scarring (i.e. the clarity of the cornea) resulting with the use of amniotic membrane was subjectively compared to cases where a permanent bulbar conjunctival graft was performed following keratectomy combined with strontium-90 irradiation or cryotherapy (n = 3 eyes). Recurrence was defined as the postoperative and postirradiation regrowth of SCC in the same site and globe. The nine horses that received an amniotic membrane graft after keratectomy alone or combined with irradiation showed a minimal level of scarring in a cornea that regained a greater transparency in comparison to the horses that were treated with a bulbar conjunctival graft. All of the horses that received an amniotic membrane graft had 226 +/- 218 days of follow-up without tumor recurrence (mean +/- SD), ranging from 21 days to 778 days. The combination of superficial keratectomy alone or associated with beta-irradiation and permanent amniotic membrane transplantation is an effective treatment of corneal or corneolimbal SCC in horses. The placement of an amniotic membrane material represents an alternative surgical procedure to bulbar conjunctival grafts, especially if there is a lack of bulbar conjunctiva tissue available after tumor resection or if a particularly large corneal resection is necessary. The amniotic membrane is incorporated into the corneal defect and seems to create noticeably much less scarring than a corneal defect covered by bulbar conjunctiva.