Sheraz M. Daya

Long-term outcomes of keratolimbal allograft for the treatment of severe ocular surface disorders

PURPOSE To investigate the long-term outcome of keratolimbal allograft (KLAL) for the treatment of severe ocular surface disorders. DESIGN Retrospective, noncomparative case series. PARTICIPANTS Twenty patients (23 eyes) with severe ocular surface disorders. INTERVENTION Thirty-three KLAL procedures were performed. Ten patients (10 eyes) underwent KLAL in combination with other surgical procedures. Oral or topical cyclosporine or both were used after surgery in 15 patients to prevent allograft rejection. MAIN OUTCOME MEASURES Reconstruction of the ocular surface with restoration of phenotypic corneal epithelium, reduction of corneal vascularization and conjunctivalization, decreased pain, and visual improvement. RESULTS The mean follow-up was 60 months (range, 15-96 months). Eight eyes (24.2%) never reepithelialized and were considered primary failures. The remaining 25 grafts initially restored a phenotypic corneal epithelium, but at last follow-up only 7 (21.2%) were stable. Graft survival rate was 54.4% at 1 year, 33.3% at 2 years, and 27.3% at 3 years. Visual acuity improved or was unchanged in 19 eyes (82.6%) and decreased in 4 eyes (17.4%). Seventeen corneal transplantations (3 lamellar keratoplasties and 14 penetrating keratoplasties) were performed either in combination with or after a KLAL. All three lamellar keratoplasties were successful, whereas 13 of the 14 penetrating keratoplasties failed. Cyclosporine was used initially in high-risk recipients and later in all recipients. Allograft rejection episodes occurred in 13 KLAL procedures of 11 eyes (39.4%) and were more common in patients treated with cyclosporine compared with the untreated group (87.5% vs. 22.2%). Graft survival was longer in the cyclosporine-treated group compared with the untreated group. CONCLUSIONS Keratolimbal allograft is useful in ocular surface reconstruction and restores phenotypic corneal epithelium. Graft survival rate, however, decreases dramatically over a 2-year period. Long-term use of cyclosporine appears to prolong graft survival but does not prevent acute allograft rejections.

Penetrating keratoplasty: indications over a 10 year period

Aims: To determine the indications for penetrating keratoplasty (PK) at the Corneoplastic Unit and Eye Bank, UK, a tertiary referral centre, over a 10 year period. Methods: Records of all patients who underwent PK at our institution between 1990 and 1999 were reviewed retrospectively. Of the 1096 procedures performed in this period, 784 records were available for evaluation (72%). Results: Regrafting was the most common indication, accounting for 40.9% of all cases. Keratoconus was the second most common indication (15%), followed by Fuchs’ endothelial dystrophy (9.3%), pseudophakic bullous keratopathy (7.6%), and viral keratitis (5.9%), which included both herpes simplex and herpes zoster and showed a statistically significant decreasing trend using regression analysis (p<0.005). Among the regraft subgroup, viral keratitis accounted for 21.2% as the underlying primary diagnosis. The most common cause for graft failure in the regraft subgroup was endothelial failure (41.8%). Conclusion: Regrafting is the leading indication for PK; viral disease—although declining—is the leading primary diagnosis.

Excimer Laser Photorefractive Keratectomy in High Myopia: A Multicenter Study

Excimer photorefractive keratectomy was performed at three centers on 16 highly myopic eyes (8 diopters [D] or more) and followed up for 6 months. Ablation depths ranged from 137 to 230 microns. The preoperative spherical equivalent of myopia ranged from -8.62 D to -14.50 D (mean +/- SD, -11.57 +/- 1.62 D). Six months after surgery, the mean refraction (spherical equivalent) was -0.90 +/- 2.13 D. Eleven of 16 eyes achieved refractions within 2 D of that attempted. All eight patients at one site were treated with a maximum-beam diameter of 6.0 mm and were corrected to within 2 D of that attempted, and all were 20/40 or better uncorrected. Three of eight eyes at the other two sites were treated with a 5.5- or 5.6-mm maximum-beam diameter, which achieved corrections within 2 D of that attempted. The epithelium healed within 3 to 4 days, and there were no erosions. Mild subepithelial reticular haze, similar to that seen with excimer photorefractive keratectomy for lower myopia, was seen in all patients, with two patients experiencing more significant corneal haze. This peaked at 3 to 6 weeks and then gradually diminished. All but two patients had a return of their best corrected preoperative visual acuity to within one Snellen line at 6 months. This preliminary study shows excimer photorefractive keratectomy to be a promising surgical treatment for patients with higher myopia.

LIVING RELATED CONJUNCTIVAL LIMBAL ALLOGRAFT FOR THE TREATMENT OF STEM CELL DEFICIENCY

PURPOSE To evaluate the outcomes of living related conjunctival limbal allograft transplantation for the treatment of stem cell deficiency. DESIGN Retrospective, noncomparative case series. PARTICIPANTS Nine living related donors, eight recipients (10 eyes) with Stevens-Johnson syndrome (3 eyes), ectodermal dysplasia (3 eyes), chemical injury (2 eyes), ocular cicatricial pemphigoid (1 eye), and atopic keratoconjunctivitis (n = 1). INTERVENTION Four clock hours of limbal conjunctival tissue from the best matched human leukocyte antigen (HLA) relative donor were transplanted to the recipient eye superiorly and inferiorly after conjunctival peritomy and removal of conjunctival pannus. Systemic cyclosporine was administered to all recipients. MAIN OUTCOME MEASURES Restoration of corneal epithelium, reduction of vascularity and conjunctivalization, improved comfort, improved corneal clarity, and visual improvement. RESULTS Mean follow-up period was 26.2 months. Two highly inflamed eyes failed to initially epithelialize. The remainder all survived with restoration of corneal epithelium and reduction of vascularization. Corneal opacification was reduced (four of eight eyes) and visual improvement was achieved in seven eyes. All five eyes with pain had an improvement in symptoms. Allograft rejection occurred in two eyes (25%), and both were treated successfully. Both eyes had two class I HLA mismatches, and both had an underlying diagnosis of Stevens-Johnson syndrome. One eye developed a recurrent epithelial defect and perforated, requiring a penetrating keratoplasty that remained clear with an intact epithelial surface. The two initial failures also perforated and required penetrating keratoplasties that failed. None of the donor eyes had any complications. CONCLUSIONS Restoration of the ocular surface by HLA-matched conjunctival limbal allograft transplantation can be accomplished in selected recipients. Systemic cyclosporine, even at low doses, is useful in ensuring long-term survival.

Avellino Corneal Dystrophy: Clinical Manifestations and Natural History

PURPOSE The pathologic features of a variant of granular corneal dystrophy has been described in which the presence of lattice changes in addition to characteristic granular lesions has been documented. The authors investigated the mode of inheritance, natural history, and clinical manifestations of this dystrophy. METHODS A family with this condition was investigated, and a pedigree was established. Family members underwent ophthalmic examination, and ophthalmic history was obtained. In addition, pathologic examination of corneal tissue from affected patients was performed. RESULTS Similar to the four previously described cases, this family also traced its origins to Avellino, Italy. This autosomal dominant condition affected 27 of 92 family members, ranging in age from 5 to 77 years. Granular deposits were the earliest and most common manifestations. Lattice lesions were present in some patients with granular lesions. Older patients had anterior stromal haze between deposits, which impaired visual acuity. Recurrent granular deposits were noted in donor corneal tissue after penetrating keratoplasty for this condition. Pathologic examination of corneal tissue from affected patients confirmed the presence of hyaline material seen in granular dystrophy as well as fusiform deposits of amyloid, similar to those seen in lattice dystrophy type I. CONCLUSION This study establishes the natural history and clinical manifestations of this condition.

Penetrating Keratoplasty and Transscleral Fixation of Posterior Chamber Lens

We reviewed the outcome in 115 patients who underwent penetrating keratoplasty and transscleral fixation of a posterior chamber lens. One patient died soon after surgical procedures, and nine patients were lost to follow-up, leaving a cohort of 105 patients. Mean follow-up time was 26.8 months (range, six to 43 months). Visual acuity of 20/40 or better was found in 29 patients (27.6%) and 20/50 to 20/200 in 37 patients (35.2%). Reasons for poor visual outcome included cystoid macular edema in ten patients (9.5%), age-related macular degeneration in six patients (5.7%), and retinal detachment in four patients (3.8%). None of the patients developed lens decentration. There were no instances of hyphema and only one patient had a perioperative limited suprachoroidal hemorrhage. New-onset increase in intraocular pressure developed in 20 of 66 patients (30.3%). Analysis of the 39 patients with preoperative increase in intraocular pressure that required medical treatment demonstrated an improvement in 13 patients (33.3%), worsening in 12 patients (30.8%), and unchanged status in 14 patients (35.9%). The exposed haptic suture was covered by using one of the following three alternative methods: a conjunctival flap, a scleral flap, or a corneal tissue button. Exposure of the haptic suture through the conjunctiva was a complication in 21 patients (20%). Of these 16 (76.1%) occurred in the group with a conjunctival covering, five (23.8%) occurred in the group with a scleral flap, and none occurred in the corneal tissue button group. This study demonstrated that transscleral fixation of a posterior chamber lens is a viable option in the treatment of patients undergoing penetrating keratoplasty and intraocular lens implantation with absent capsular support.

Penetrating keratoplasty: outcomes from a corneal unit compared to national data

Aims: To determine long term graft survival rates and visual results for different indications for penetrating keratoplasty from a single institution over 10 years and compare these to national outcome data. Methods: Retrospective chart analysis. 784 records were available for review of 1096 consecutive penetrating keratoplasty procedures performed between 1990 and 1999 (72%). Outcomes of graft survival, visual acuity, and astigmatism were analysed and compared to national outcome data supplied by the UK Transplant Service. Results: At 5 year follow up, overall graft survival was 66%. This was subdivided into 98% for keratoconus, 86% for viral keratitis, 85% for Fuchs’ dystrophy, 84% for pseudophakic bullous keratopathy, 55% for regrafts, and 57% for other diagnoses. There was a significantly higher graft survival rate for all diagnostic subgroups except Fuchs’ dystrophy at 3 years of follow up compared to the national average. Best corrected visual acuity at 5 years was 6/18 or better in 53% of cases. The mean keratometric astigmatism was 3.4 dioptres. Conclusion: Penetrating keratoplasty is a safe and effective treatment for selected corneal disorders. Penetrating keratoplasty for viral keratitis may achieve good results with long term antiviral treatment. Patients may achieve better outcomes if their surgery is performed at specialist centres.

The potential for eye bank limbal rings to generate cultured corneal epithelial allografts.

Purpose. Patients with severe limbal deficiencies are unable to maintain a stable corneal surface. If sheets of cultured allogeneic corneal epithelium could be prepared from eye banked corneal limbal rings, which are normally discarded after keratoplasty, the sheets may be beneficial for grafting onto patients with limbal stem cell deficiencies. Method. Biopsies of limbal tissue (2–3 mm2) removed from organ-cultured corneal limbal rings or from fresh whole globes were either trypsinized or set up as explants to assess their potential for corneal epithelial cell production. Results. Several biopsies were taken from each of 21 organ-cultured limbal rings and 10 fresh cadaveric globes. Cultures were generated from every cadaveric eye (10/10), although not all biopsies from the same eye gave rise to cultures. Confluent sheets of cultured cells were also produced successfully from limbal rings that had been in organ culture for up to 25 days, but the success rate from limbal ring material was variable (14/21). An analysis of parameters associated with each limbal ring was carried out in an attempt to identify the reasons for the different efficiencies of epithelial production. No obvious single parameter correlation was detected, although there was a trend to poorer efficiency with increased donor age. Conclusions. Confluent sheets of cultured corneal epithelial cells, suitable for grafting, can be produced from limbal tissue taken from eye bank organ-cultured corneas, although it takes longer, on average, to reach confluence (17–21 days) than an equivalent sample from a fresh eye (9–12 days).

Reshaping procedures for the surgical management of corneal ectasia.

&NA; Corneal ectasia is a progressive, degenerative, and noninflammatory thinning disorder of the cornea. Recently developed corneal reshaping techniques have expanded the treatment armamentarium available to the corneal specialist by offering effective nontransplant options. This review summarizes the current evidence base for corneal collagen crosslinking, topography‐guided photorefractive keratectomy, and intrastromal corneal ring segment implantation for the treatment of corneal ectasia by analyzing the data published between the years 2000 and 2014. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Reproducibility of LASIK flap thickness using the Hansatome microkeratome.

Purpose: To evaluate the actual versus the expected thickness of laser in situ keratomileusis (LASIK) flaps and to determine the factors that affect flap thickness. Setting: Centre For Sight, Queen Victoria Hospital, East Grinstead, United Kingdom. Methods: A retrospective analysis of LASIK procedures in 757 consecutive eyes was done. The surgery was performed by a single surgeon using 2 Hansatome® microkeratomes (Bausch & Lomb) with 160 &mgr;m and 180 &mgr;m heads. Patient age, preoperative manifest refraction, automated keratometry, preoperative central pachymetry, and intraoperative stromal pachymetry were evaluated to determine whether they influenced the actual flap thickness. Results: Bilateral LASIK was performed in 343 patients (686 eyes). The 160 &mgr;m head was used in 641 eyes (84.6%) (Group 1) and the 180 &mgr;m head, in 116 eyes (15.4%) (Group 2). The mean preoperative manifest refraction spherical equivalent (SE) was −3.9 diopters (D) ± 4.5 (SD) (range +7.4 to −25.0 D) in Group 1 and −4.4 ± 3.7 D (range +7.1 to −12.9 D) in Group 2. The mean preoperative keratometry reading was 43.6 ± 1.8 D (range 36.0 to 48.6 D) and 43.6 ± 1.8 D (range 35.9 to 47.0 D), respectively; the mean preoperative central pachymetry was 543 ± 35 &mgr;m (range 447 to 643 &mgr;m) and 548 ± 31 &mgr;m (range 453 to 613 &mgr;m), respectively; and the mean flap thickness was 116.4 ± 19.8 &mgr;m and 117.3 ± 18.0 &mgr;m, respectively. The difference between the actual and the expected flap thickness in each group was statistically significant (P<.001). There was no significant difference in the actual flap thickness between the 2 Hansatomes. The preoperative SE and central pachymetry were the only factors that influenced the actual flap thickness (P<.05); thin flaps were more common with increasing myopia and increasing corneal thickness. Conclusions: Spherical equivalent and preoperative pachymetry were the principal factors that influenced flap thickness. Preoperative keratometry values and patient age did not influence the actual flap thickness.