Corneal replacement using a synthetic hydrogel cornea, AlphaCor: device, preliminary outcomes and complications.

PURPOSE: Clinical assessment of outcome of corneal replacement with a synthetic cornea, AlphaCor, in patients considered at too high risk for conventional penetrating keratoplasty with donor tissue to be successful, but excluding indications such as end-stage dry eye that might be suited to traditional prosthokeratoplasty. METHODS: All patients in the multicentre clinical trial were managed according to an approved protocol, with Ethics Committee approval in each centre. Preoperative visual acuity ranged from perception of light (PL) to 6/60 (20/200). Implantation was by means of an intralamellar technique, with a conjunctival flap in most cases. Tissues anterior to the optic were removed as a secondary procedure. RESULTS: Up to 30 November 2001, 40 AlphaCor devices had been implanted in 38 patients, of mean age 60 years. Follow-up ranged from 0.5 months to 3 years. There had been one extrusion (2.5%) and four cases (10%) where a device had been removed due to melt-related complications. All five of these cases received a donor corneal graft after the device was removed, with these grafts remaining anatomically satisfactory and epithelialised to date. Corneal melts in AlphaCor recipients were found to be strongly associated with a history of ocular herpes simplex infection. Two further devices (5%) were removed owing to reduced optic clarity after presumed drug-related deposition, and have been successfully replaced with second devices. Mean preoperative best-corrected visual acuity was hand movements. Visual acuities after surgery ranged from PL to 6/6(-2) (20/20(-2)). CONCLUSIONS: Early results suggest that the AlphaCor, previously known as the Chirila keratoprosthesis (Chirila KPro), has a low incidence of the complications traditionally associated with keratoprostheses and can be effective in restoring vision in patients considered untreatable by conventional corneal transplantation. Importantly, the device can be replaced with a donor graft in the event of development of a significant complication. A history of ocular herpes simplex is a contraindication to AlphaCor implantation. Ongoing monitoring of clinical outcomes in all patients will allow the indications for AlphaCor, as opposed to donor grafts, to be determined.

Atypical presentation of Acanthamoeba keratitis.

PURPOSE: To present two cases of minimal pain Acanthamoeba keratitis to alert clinicians to remember Acanthamoeba when evaluating atypical cases of keratitis. METHODS: The histories of two cases were reviewed with attention to clinical presentation subjective complaints, treatment, and long-term outcome. RESULTS: In case 1, a 24-year-old man presented with decreased vision and an irritated feeling in his eye. He did not wear contact lenses. His initial diagnosis was adenoviral conjunctivitis. One month later, he was diagnosed with atypical herpes simplex keratitis and started on acyclovir. Two weeks later, he was referred to the Cornea Service. Further history revealed the patient to be a professional triathlete who trained by swimming in a fresh water pond. He was found to have an unusually high pain tolerance. Biopsy revealed Acanthamoeba. He was admitted for intensive therapy with neomycin, propamidine isethionate, and polyhexamethylene biguanide. Two years after diagnosis, he has best-corrected visual acuity of 20/100. In case 2, a 28-year-old man with known herpes simplex keratitis presented with decreased vision. He was started on topical trifluridine. After 6 weeks without improvement, he was referred for corneal evaluation. His eye always remained comfortable. Corneal sensation was markedly decreased. Further history revealed that he swam in fresh water. Biopsy was positive for Acanthamoeba. After 1 year of therapy with polyhexamethylene biguanide and neomycin, visual acuity was 20/200, and the patient underwent a corneal transplant. CONCLUSION: Acanthamoeba keratitis must be considered in the differential diagnosis of keratitis, even without the classic presentation of severe pain and predisposing corneal trauma, including contact lens wear.

A comparison of different depth ablations in the treatment of painful bullous keratopathy with phototherapeutic keratectomy.

AIM: To study the efficacy of phototherapeutic keratectomy (PTK) for pain relief for patients with painful bullous keratopathy and poor visual potential. METHODS: Patients with painful bullous keratopathy and poor visual potential were treated with superficial PTK (8-25 microm), intermediate (50-100 microm) or deep PTK (25% stromal thickness) using the Nidek EC5000 excimer laser after manual epithelial debridement. Follow up ranged from 1 to 24 months (mean 6.5 months). Outcome measures included symptomatic relief and need for further treatment. RESULTS: In the superficial PTK group five of eight (62%) patients improved symptomatically after treatment. The three (38%) who did not improve went on to have penetrating keratoplasty for pain relief. In the intermediate depth group only two of five (40%) patients had symptom alleviation. The three others (60%) required further procedures. 20 of 24 (83%) patients treated with deep PTK had significant or total alleviation of symptoms. Of these, one developed acute anterior uveitis 9 months after PTK and two required botulinum ptosis for persistent corneal epithelial defects, one of whom had three consecutive episodes of microbial keratitis. Three of 24 suffered occasional discomfort and one patient required a penetrating keratoplasty for continued pain. CONCLUSION: PTK can be a useful therapeutic measure in painful bullous keratopathy with poor visual potential. Deep PTK appears to be more successful in pain management than superficial treatment.

Management of alkali burns : an 11-year retrospective review.

OBJECTIVE: To review the spectrum of patients with alkali burns admitted over an 11-year period and to assess the clinical outcomes after the introduction of a standard alkali burn treatment protocol. DESIGN: Retrospective nonrandomized comparative study. PATIENTS AND INTERVENTIONS: A total of 121 patient records with alkali burns (n = 177 eyes) admitted to a tertiary hospital between 1987 and 1998 were reviewed. Eyes treated with a standard alkali burn treatment protocol, which included intensive topical steroids, ascorbate, citrate, and antibiotics, were compared with eyes treated by conservative management with antibiotics, and a short course of steroids. MAIN OUTCOME MEASURES: Time to corneal reepithelialization, final best-corrected visual acuity, and time to visual recovery, length of hospital stay, and complications were analyzed. RESULTS: The standard protocol tended to delay corneal reepithelialization by one day (P: = not significant) in eyes with grade 1 burns (n = 76) and by 2 days (P: = 0.04) in grade 2 burns (n = 52), with no difference in final visual outcome. There were 37 eyes with grade 3 burns. Those treated with the standard protocol showed a trend toward more rapid corneal reepithelialization. Twenty-seven of 29 (93%) eyes with grade 3 injuries achieved a final best-corrected visual acuity of 20/40 or better compared with 3 of 6 (50%) eyes not treated according to the standard protocol (P: = 0.02). Eyes with grade 4 burns (n = 12), whether treated with the standard protocol or not, required 10 to 12 weeks for corneal reepithelialization. There was no statistically significant difference in final visual acuity. CONCLUSIONS: On the basis of our findings, a number of recommendations can be made for the management of alkali injuries. Patients with a grade 1 or 2 injury do not require routine admission and do not benefit from the use of intensive treatment with ascorbate and citrate. A trend toward more rapid healing and a better final visual outcome were apparent in grade 3 burns, but our standard protocol made no difference in grade 4 burns.

Pterygium surgery in Victoria: a survey of ophthalmologists.

AIM: To determine the surgical approaches and adjunctive therapy es currently used by Victorian ophthalmologists for the treatment of primary and recurrent pterygia. METHOD: Ophthalmologists practising in Victoria were asked to complete a written survey relating to their experience with pterygium surgery. RESULTS: Responses were received from 142 of 165 ophthalmologists surveyed (86%). Of these, 107 (75%) had performed at least one pterygium operation during the preceding 2 years. Excision followed by beta irradiation was the most commonly performed procedure for both primary (57%) and recurrent (35%) pterygia. The next most commonly performed procedure for primary pterygia was excision leaving bare sclera (15%) and, for recurrent pterygia, excision with autologous conjunctival transplantation (26%). Considerable variation was observed in surgical technique, choice of adjunctive therapy, postoperative care and in the surgeons' estimates of the frequency of major complications. CONCLUSION: Although there is little consensus regarding the surgical management of pterygium, beta irradiation remains the most commonly used adjunctive therapy in Victoria.

Pyogenic granuloma of the cornea.

BACKGROUND: Ocular pyogenic granulomata are uncommon and are often associated with a chalazion or previous ocular and adnexal surgery The avascular nature of the cornea may explain the rarity of pyogenic granulomata at this site. We report on a case of corneal pyogenic granuloma following previous corneal surgery. METHODS: Ophthalmologists who had treated the patient previously were contacted and earlier clinical notes and histopathological examinations were reviewed. The clinical course following excision of the pyogenic granuloma is described, as are the histopathological findings. RESULTS: Histological examination confirmed the diagnosis of pyogenic granuloma. Excision was followed by a clinical recurrence at a different site with spontaneous resolution. CONCLUSIONS: Pyogenic granulomata of the cornea are rare. However, the present case illustrates the importance of considering benign inflammatory causes in the differential diagnosis of a corneal mass lesion so as to avoid unnecessarily aggressive intervention. To our knowledge, spontaneous resolution of a corneal pyogenic granuloma has not been previously described.

Delayed microbial keratitis following radial keratotomy.

BACKGROUND: We report on the case of a 46-year-old female who presented with delayed microbial keratitis 10 years after uncomplicated radial keratotomy. METHODS: The pre- and postoperative clinical record was reviewed following her presentation to the Corneal Clinic. Slit-lamp examination revealed a stromal inflammatory infiltrate at the site of an earlier radial keratotomy incision. The lesion was scraped and a coagulase-negative Staphylococcus aureus was cultured in enrichment broth. RESULTS: The keratitis was treated successfully with combination fortified topical antibiotics without loss of vision. CONCLUSIONS: Although microbial keratitis is a well documented complication of incisional refractive procedures, it is rarely encountered as late as one decade after surgery. Patients should be warned of this possibility and the need for prompt treatment.

Late recurrences and the necessity for long-term follow-up in corneal and conjunctival intraepithelial neoplasia.

PURPOSE: The purpose of the study was to elucidate the natural history of corneal-conjunctival intraepithelial neoplasia (CIN) and suggest treatment and follow-up guidelines. METHODS: The records of all histologically proven cases of CIN at the Royal Victorian Eye and Ear Hospital between 1979 and 1994 were reviewed. RESULTS: Seventy-nine eyes of 76 patients had a pathologic diagnosis of CIN and were observed for up to 15 years. The lesion recurred in 31 eyes (39%) overall. There was no statistical difference shown in the likelihood of recurrence based on histologic classification. Complete excision was attempted in each case. In 18 eyes, dysplastic cells were evident at the excision margin. Ten (56%) of these tumors recurred, compared to a 33% recurrence rate in completely excised lesions. The time to the first recurrence ranged from 33.0 days to 11.5 years between the first and second surgeries, with 11 lesions recurring after more than 4 years. Incompletely excised lesions reappeared more rapidly (average, 2.5 years) than did those with clear surgical margins (average, 3.8 years). Seven cases progressed to invasive squamous cell carcinoma and four cases led to blindness or removal of the eye. CONCLUSIONS: This study suggests that excision margin at the time of surgery is the most important factor in predicting recurrence. The slow growth of the recurrent lesions combined with the ever-present malignant potential leads the authors to suggest that all patients with a history of CIN warrant annual follow-up for the remainder of their lives.

Retreatment after excimer laser photorefractive keratectomy. The Melbourne Excimer Laser Group.

PURPOSE: To determine the risk factors for undercorrection of myopia after photorefractive keratectomy and to evaluate the efficacy and safety of retreatment. METHODS: A VISX Twenty/Twenty excimer laser was used to treat myopia and myopic astigmatism of up to -15.00 diopters (spherical equivalent) at the corneal plane. Retreatments were performed primarily for undercorrection with or without coexistent corneal haze or abnormalities on videokeratoscopy. Not every patient who was undercorrected requested retreatment. RESULTS: Of 645 eyes (440 patients) followed up for more than 12 months, 58 eyes (9%) required retreatment. The retreatment rate increased with increasing myopia: 17 (5%) eyes with myopia of less than -5.00 diopters, 30 (13%) eyes with myopia of -5.01 to -10.00 diopters, and 11 (19%) eyes with myopia of greater than -10.00 diopters required a second procedure. A higher retreatment rate was observed after astigmatic corrections than after spherical corrections. Corneal haze after retreatment was no greater than that observed after initial procedures. Twelve months after primary procedures, 378 (75%) of 504 eyes were within 1.00 diopter of emmetropia, whereas 27 (69%) of 39 eyes attained this result after retreatment. A total of 383 (76%) of 504 eyes attained uncorrected visual acuity of 20/40 or better after primary procedures, compared with 25 (64%) of 39 eyes after retreatment. CONCLUSIONS: The risk of undercorrection requiring retreatment after photorefractive keratectomy increases with the magnitude of the primary treatment. Although less successful than initial procedures, retreatment appears to enhance the results of photorefractive keratectomy.

One-year evaluation of excimer laser photorefractive keratectomy for myopia and myopic astigmatism. Melbourne Excimer Laser Group.

OBJECTIVE: To evaluate prospectively the efficacy and safety of excimer laser photorefractive keratectomy in the treatment of myopia and myopic astigmatism. METHODS: Up to 15 diopters (D) of myopia with or without astigmatism of less than 6 D was treated with an excimer laser (VISX Twenty/Twenty). One hundred fifty procedures have been followed up for more than 12 months. RESULTS: Postoperative refractions were generally stable after 3 months without significant early overcorrection. Of those eyes treated with spherical equivalents of 5 D or less, 96% were within 1 D of the targeted refraction after photorefractive keratectomy and 88% had uncorrected visual acuities of 20/40 or better. At 12 months, 77% of all 150 eyes treated achieved an uncorrected visual acuity of 20/40 or better and 81% were within 1 D of the intended correction. Nine eyes (6%) lost 2 or more lines of best corrected visual acuity and 14 (9%) gained 2 or more lines. Adverse reactions were reported in 12 patients (8%) during the postoperative period. CONCLUSIONS: Photorefractive keratectomy is capable of correcting low and moderate myopic errors with a relatively high degree of accuracy and safety. The predictability and stability of the postoperative refraction during the first 12 months seem to be good.

Necrotising anterior scleritis after pterygium surgery.

Necrotising anterior scleritis is a rare sequela of ocular surgery. Typically an intense scleral inflammation develops at or adjacent to the site of the previous surgery. Necrosis supervenes and may then progress circumferentially to involve much of the anterior sclera. Surgically induced necrotising scleritis (SINS) has been previously described after cataract extraction, trabeculectomy, retinal detachment and strabismus surgery. We report three cases of SINS following pterygium excision. In each case the disease was prolonged, progressive and required protracted immunosuppressive therapy.

Sterile ocular inflammatory reactions to monofilament suture material.

OBJECTIVE: To report six cases of sterile inflammatory reactions to fine monofilament suture materials, which is exceedingly rare in ophthalmology. METHODS: We report six patients (four underwent penetrating keratoplasty and two underwent cataract surgery) with unusually severe local inflammatory reactions to suture material. RESULTS: Patients developed multiple focal inflammatory infiltrates and corneal oedema related to 10/0 monofilament nylon sutures. Four patients had evidence of either atopy or raised serum IgE and one had an autoimmune disorder (systemic lupus erythematosis). Onset was four to 11 days in five cases and six weeks in one. Allograft reaction occurred in two of the four corneal grafts, and three grafts failed. One of the cataract patients developed significant against-the-rule astigmatism. Microbial cultures of corneal scrapings, donor corneal rims, and suture material were generally negative. Polymorphonuclear leucocytes were noted on Gram stain in four cases, and cytology of corneal scrapings demonstrated eosinophils in one case. CONCLUSIONS: Sterile inflammatory reactions to monofilament suture material are an uncommon complication of ocular surgery which may lead to corneal graft failure, and which is more common in atopic individuals. Systemic steroid therapy may be required.

Scedosporium prolificans sclerokeratitis.

BACKGROUND: The fungus Scedosporium prolificans was first described as a human pathogen in 1984, and has been associated with metastatic endophthalmitis and one previously reported case of sclerokeratitis. METHODS: We report a case of S. prolificans sclerokeratitis in the setting of late scleral necrosis complicating pterygium surgery with adjunctive beta-irradiation. RESULTS: A poor clinical response to topical natamycin and amphotericin B, and systemic itraconazole and ketoconazole was encountered. Enucleation was required, with subsequent microbiological cure. Pathological correlation is described. CONCLUSIONS: S. prolificans infections often respond poorly to medical therapy. Early surgical intervention is indicated in culture-proven scleritis due to Scedosporium prolificans.