Survival of Donor Epithelial Cells after Limbal Stem Cell Transplantation

PURPOSE

To determine the long-term fate of donor epithelial cells after limbal allograft transplantation.

METHODS

Corneal buttons and peripheral blood leukocytes were obtained at the time of penetrating keratoplasty from three patients who had undergone a successful limbal allograft transplantation. Microdissection was used to remove the corneal epithelial cells from the button. The presence of donor and recipient epithelial cells in each sample was determined by using PCR for DNA microsatellites. Phenotypic analysis of the epithelium was performed by immunohistochemistry.

RESULTS

Various patterns of DNA microsatellites were observed. Nonrecipient cells (presumed to be donor) were consistently detected in all three corneal buttons. In two of the three cases, recipient cells were also detected, whereas in the third case, exclusively donor epithelial cells were found at 3.5 years after limbal allograft transplantation. Mild T-lymphocytes and macrophages were observed in one of the corneal buttons.

CONCLUSIONS

This study provides evidence for the persistence of donor epithelial cells up to 3.5 years after limbal allograft transplantation and supports the use of systemic immunosuppressive therapy.

Mycophenolate mofetil for the treatment of scleritis

PURPOSE

To evaluate the usefulness of mycophenolate mofetil (MMF) (CellCept, Roche, Nutley, NJ), an antimetabolite immunosuppressant with a selective antiproliferative effect on T and B lymphocytes, for the treatment of scleritis.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Eight patients with scleritis treated with MMF in a tertiary referral center.

METHODS

Review of the clinical records of patients evaluated at the National Eye Institute and prescribed MMF for the treatment of scleritis.

MAIN OUTCOME MEASURES

Control of scleral inflammation, the ability to taper prednisone or other immunosuppressive medications, and adverse events were recorded for each patient. Mycophenolate mofetil was determined to be an effective steroid-sparing agent if the daily prednisone dosage could be reduced by 50% or more and was determined to be an effective adjunctive immunosuppressive agent if the scleral inflammation was controlled in patients with active scleritis.

RESULTS

Four patients with diffuse anterior scleritis, two with necrotizing scleritis with inflammation, one with nodular anterior scleritis, and one with nodular anterior and posterior scleritis, were identified. Mycophenolate mofetil administration was initiated as a steroid-sparing agent in 4 patients with controlled scleritis and as an additional immunosuppressive agent in 4 patients with active scleritis receiving concomitant treatment with prednisone and cyclosporine or methotrexate. In 3 of the 4 patients started on MMF as a steroid-sparing agent, the scleritis remained controlled while the prednisone dosage was tapered by more than 50%. One of the patients started on MMF as a steroid-sparing agent had recurrent scleritis, and each of the patients with active scleritis continued to have persistent scleral inflammation requiring additional immunosuppressive therapy. Adverse effects recorded in 4 of the 8 patients included a rash, gastrointestinal symptoms, paresthesias, and laboratory evidence of hepatotoxicity and renal toxicity.

CONCLUSIONS

Although MMF maybe be useful as a steroid-sparing agent, it was not effective as an adjunctive immunosuppressive agent in patients with active scleritis in our small, tertiary referral series. The adverse effects encountered with the use of MMF in this study cannot be attributed conclusively to MMF and are more likely complications of the multiagent systemic immunosuppressive therapy required for the treatment of recalcitrant scleritis.

Ocular surface reconstruction: limbal stem cell transplantation

In summary, the management of patients with severe ocular surface disease remains difficult. Significant progress has been made toward understanding limbal stem cell disease, and surgical treatments have been refined. Short- and long-term successes have been achieved and have improved the quality of life for patients who otherwise have had no other treatment options. Further research is needed to determine the factors leading to successful long-term stem cell transplantation and those factors associated with transplantation failure. Developments in the management of limbal stem cell disease are progressing rapidly, and the long-term outlook for patients with this challenging disease continues to improve.

Management of aniridic keratopathy with keratolimbal allograft: a limbal stem cell transplantation technique

OBJECTIVE

Aniridic keratopathy is a major cause of vision loss in patients with aniridia. Penetrating keratoplasty has been proven ineffective for the long-term treatment of this disorder because it does not address the stem cell deficiency that is the primary etiologic factor. We evaluated the role of keratolimbal allograft (KLAL), a stem cell transplantation technique, for the treatment of patients with aniridic keratopathy.

DESIGN

Retrospective noncomparative interventional case series.

PARTICIPANTS

Thirty-one eyes of 23 patients with aniridic keratopathy.

INTERVENTION

KLAL.

MAIN OUTCOME MEASURES

Ocular surface stability, visual acuity, and success of subsequent penetrating or lamellar keratoplasty.

RESULTS

Thirty-one eyes of 23 patients were treated with KLAL and followed up for 12 to 117 months (mean, 35.7 months). Twenty-three eyes (74.2%) achieved a stable ocular surface. Overall, the mean visual acuity improved from 20/1000 to 20/165. Twenty eyes (64.5%) underwent subsequent penetrating keratoplasty. Fourteen corneal transplant grafts (70.0%) were successful, and six (30.0%) failed. Nineteen (90.5%) of 21 eyes receiving systemic immunosuppression obtained a stable ocular surface, whereas only 4 (40.0%) of 10 eyes not receiving systemic immunosuppression achieved ocular surface stability (P < 0.01).

CONCLUSIONS

KLAL is effective in treating aniridic keratopathy. Patients receiving systemic immunosuppression have a greater likelihood of achieving ocular surface stability and improved visual acuity compared with those who receive only topical immunosuppression.

Intraocular hemorrhage after systemic thrombolytic therapy in a patient with exudative macular degeneration

PURPOSE

To report a hemorrhagic complication from thrombolytic therapy in a patient with exudative macular degeneration.

CASE REPORT

A 75 year old patient with exudative macular degeneration developed pain and loss of vision in the left eye shortly after receiving tissue plasminogen activator (t-PA) for a myocardial infarction. Examination revealed the patient to be in angle closure. A CT scan revealed the etiology of the angle closure to be a dense vitreous hemorrhage pushing the iris-lens diaphragm forward. Intraocular pressure was treated successfully, but the final visual acuity was only light perception.

CONCLUSIONS

Thrombolytic therapy can lead to devastating intraocular hemorrhages. The presence of exudative macular degeneration may potentially increase the risk of developing such complications.

Immunosuppression in uveitis

The treatment of ocular inflammatory disease continues to be a major challenge as the clinician tries to balance the risks and the benefits of immunosuppressive therapy. Currently, corticosteroids, antimetabolites, and calcineurin inhibitors are the most commonly used agents. Biologically active agents including monoclonal antibodies, however, provide a promising new form of treatment that can target the immune system more specifically and more safely. Long-term studies are needed to determine the role of biologic agents in the treatment of uveitis.

Feline immunodeficiency virus-mediated gene therapy of middle ear mucosa cells

HYPOTHESIS

To investigate the feasibility of gene therapy of the middle ear mucosa using a novel vector.

BACKGROUND

Given present medications are unable to affect chronic otitis media, cholesteatoma, or tympanic membrane perforation, newer methods of treatment like gene therapy for these diseases must be explored. These genes can then be used to alter cytokines in the middle ear, slow or stop cholesteatoma growth, or improve tympanic membrane perforation healing. Feline immunodeficiency virus (FIV), a new lentiviral vector has been found to have greater than 90% efficiency in transfecting epithelial cells. Therefore, in vivo gene therapy of middle ear mucosa cells was attempted.

METHODS

Twenty microliter of 5x10(5) vectors per ml FIV carrying the gene for green fluorescence protein (GFP) was introduced into the middle ears of Sprague-Dawley rats via a bulla approach.

RESULTS

Expression of the GFP gene was observed in the middle ear mucosa cells at 1 week post-inoculation indicating transfection.

CONCLUSION

Gene therapy of the middle ear is feasible with a FIV-based vector.

Keratitis caused by Candida glabrata in a patient with chronic granulomatous disease

PURPOSE

To report an unusual ocular presentation of Candida glabrata in a patient with chronic granulomatous disease.

METHODS

Interventional case report. A 15-year-old boy with chronic granulomatous disease presented with bilateral limbal infiltrates. He had been receiving broad-spectrum systemic antibiotics for recurrent liver abscesses. The keratitis did not respond to antibiotics and did not resolve after a course of topical steroids.

RESULTS

Corneal cultures revealed Candida glabrata. The same species was simultaneously isolated from the surgical drainage of the liver abscesses. The ocular and hepatic findings resolved on intravenous amphotericin B.

CONCLUSION

Candida glabrata has recently emerged as an important nosocomial pathogen. It may present as a limbal keratitis in the setting of systemic infection.

Conjunctival epithelial cells cultured on human amniotic membrane fail to transdifferentiate into corneal epithelial-type cells

PURPOSE

Previous studies on the use of human amniotic membrane (HAM) in rabbit stem cell deficiency models have found the new epithelium growing over the HAM to express cornea-specific keratins (K3 and K12) in 40% of the cases, suggesting that HAM may have induced conjunctival epithelial cells to transdifferentiate into cornea-type epithelial cells. The current study was performed to determine whether HAM could induce transdifferentiation of conjunctival epithelia] cells when cultured in vitro.

METHODS

Conjunctival grafts taken from the fornices of New Zealand white rabbits (6-12 weeks old) were placed over HAMs and lifted to an air-media interface using polypropylene double rings. These cultures were maintained in supplemented hormonal epithelial medium with and without 3T3 feeder cells. Rabbit corneal epithelial cells were cultured similarly using strips of keratolimbal grafts placed over HAM. The cultures were terminated at various times between the 8th and 15th day. The cultured epithelial cells were examined histologically and immunohistochemically using monoclonal antibodies AK-2 (to K12 keratin), AM-3 (to goblet cell mucin), and AE-5 (to K3 keratin).

RESULTS

Both conjunctival and corneal epithelial cells cultured on HAMs showed multilayered, differentiated epithelial structures. On immunohistochemical examination, both epithelial cells stained positive for AE-5. None of the cultured conjunctival epithelial cells stained positively for AK-2, while the corneal epithelial cells showed positive staining with AK-2. There were no AM-3-positive goblet cells in either epithelial cell culture. There was no difference in the immunohistochemical patterns between cultures with or without 3T3 feeder cells. However, culture without feeder cells seemed to manifest a more degenerative appearance than those with feeders.

CONCLUSION

HAM does not induce transdifferentiation of conjunctival epithelial cells into corneal-type epithelial cells under the in vitro culture conditions used in this study.

Long-term results of transsclerally sutured posterior chamber lenses in penetrating keratoplasty

PURPOSE

To evaluate the long-term safety and efficacy of transsclerally sutured posterior chamber lenses in penetrating keratoplasty.

METHODS

This was a retrospective review of 130 patients who underwent penetrating keratoplasty and placement of a transsclerally sutured posterior chamber lens with at least 1 year of follow-up. The mean follow-up period was 38.8 months. There were 61 patients who had been followed for at least 3 years (mean, 59 months).

RESULTS

At follow-up the visual acuity was 20/40 or better in 40 patients (31%) and 20/50 to 20/200 in 48 patients (36%). The primary reasons for decreased visual acuity were age-related macular degeneration (18%) and graft failure (13%). New-onset glaucoma was found in 19 of 82 patients (23%). In the 48 patients who had elevated intraocular pressures preoperatively, the pressure improved in 13 patients (27%) and worsened in 12 patients (25%). Exposure of the haptic suture through the conjunctiva occurred in 14 patients (11%) at an average of 12 months after surgery. Of these, seven (19%) occurred in patients with conjunctival flaps, and seven (16%) in patients who had scleral flaps covering the haptic suture. No erosions occurred in the cases in which the suture was rotated inside the eye.

CONCLUSION

Improvements in the surgical technique have made transsclerally sutured posterior chamber lenses safer in patients with inadequate capsular support. The long-term visual results in penetrating keratoplasty are acceptable and comparable to those of other techniques.

Tandem scanning confocal microscopic analysis of differences between epithelial healing in limbal stem cell deficiency and normal corneal reepithelialization in rabbits

PURPOSE

To analyze the differences in epithelial healing between limbal stem cell-deficient corneas and normal corneas by using in vivo confocal microscopy.

METHODS

Two different injury models were made in rabbit eyes by using n-heptanol to create a corneal epithelial defect with (limbal stem cell-deficiency model) or without (normal corneal reepithelialization model) peripheral limbal keratectomy. Using a tandem scanning confocal microscope (TSCM), we examined and compared the epithelial healing processes of the two different injury models. Impression cytology and pathologic examination were done on limbal stem cell-deficient corneas.

RESULTS

In limbal stem cell-deficient corneas, the healing epithelial cells were smaller and more variable in size compared with those in normal corneas. In limbal stem cell-deficient corneas, the epithelial thickness varied from one to six cell layers, with the middle and basal cell layer cells being lined up in a certain direction in some areas. The basement membrane was uneven and partially deficient; in some areas, the deep basal epithelial cells were mixed with fibrous strands extending from the anterior stroma. New vessels were located in various levels, from epithelium to deep stroma. These findings were not seen in the normal corneal reepithelialization. In both epithelial-healing models, particularly in the normal corneal reepithelialization, the superficial squamous cells in the early healing stage were considerably larger than those in nontraumatized normal corneas.

CONCLUSION

TSCM is a useful technique for studying the in vivo microscopic structure of many corneal diseases and injury models sequentially over time.

Comparison between the refractive results of combined penetrating keratoplasty/transsclerally sutured posterior chamber lens implantation and the triple procedure

PURPOSE

We determined how accurately we could predict the intraocular lens (IOL) power for a combined penetrating keratoplasty and transsclerally sutured posterior chamber lens implantation procedure (PK/TS-SPCL) compared with the Triple procedure (penetrating keratoplasty, extra-capsular cataract extraction, and IOL insertion).

METHODS

We retrospectively evaluated the postoperative refractive results of 27 patients who had undergone PK/TS-SPCL and compared them with those of 46 patients who had undergone a Triple procedure. All patients with a final visual acuity > 20/50 who had surgery at the University of Minnesota between January 1988 and December 1993 were included in this study.

RESULTS

The mean postoperative deviation from the predicted refractive error was 1.79 D for the Triple group and 1.81 D for the PK/TS-SPCL group (p = 0.95). Sixty-three percent of the Triple patients and 67% of the PK/TS-SPCL patients were within -2.00 D and +2.00 D of their predicted refractive error. As a group, the Triple patients had a mean postoperative keratometry reading of 44.64 compared with 45.58 for the PK/TS-SPCL patients (p = 0.12).

CONCLUSION

These results indicate that our accuracy in predicting the IOL implant power in PK/ TS-SPCL is quite comparable with that obtained for the Triple procedure, and our refractive results for each group are quite similar.

Gonioscopic evaluation of haptic position in transsclerally sutured posterior chamber lenses

PURPOSE

To determine the haptic position in transsclerally sutured posterior chamber lenses.

METHODS

Fifty eyes with transsclerally sutured posterior chamber lenses were evaluated gonioscopically to determine the superior haptic position using previous peripheral iridectomies.

RESULTS

The superior haptic of the transsclerally sutured posterior chamber lens was visualized in 31 (62%) of the eyes. In 24 (77%) of the 31 eyes, the haptic was within the ciliary sulcus, and in seven (23%), it was located posterior to the sulcus. A fibrotic membrane was detected around the sutured haptic in 20 (83%) of the 24 lenses located within the sulcus, whereas no fibrosis was seen surrounding the seven haptics outside the sulcus (P < .0001).

CONCLUSIONS

Proper positioning of the haptics may be correlated with the development of fibrosis surrounding the haptic and therefore may be an important factor in the long-term stability of transsclerally sutured posterior chamber lenses.

Heart transplantation for patients over age 60

As the proportion of people over age 60 in our society continues to rise, so does the number of potential heart transplant candidates. Advanced recipient age, however, has long been used as an exclusion criterion for transplantation, though the upper age limit remains poorly defined. The purpose of our study was to analyze the outcomes of 31 heart transplant recipients over age 60 at our institution. They were followed with regard to early and late morbidity and mortality. Mean follow-up time was 50 months. The 1- and 5-yr survival rates were 90% and 85%. These rates were not significantly different compared with younger (age 18 to 59) recipients transplanted in the same time period. The older recipients more frequently developed osteoporotic changes as well as cutaneous and visceral malignancies, but had infrequent rejection episodes. Overall, heart transplantation is safe and effective for patients over age 60 with end-stage congestive heart failure. Both 1- and 5-yr survival rates are well within the acceptable range and do not differ significantly from younger recipients. Individualized immunosuppression might help reduce the incidence of malignancy in older recipients, but further studies are needed. Matching donor and recipient age would make the best use of available organs.

Adjunctive coronary endarterectomy: improved safety in modern cardiac surgery

BACKGROUND

Advances in cardiac surgery have led to an improved safety record for coronary endarterectomy.

METHODS

We retrospectively reviewed the cases of 64 patients who underwent adjunctive coronary endarterectomy between August 1988 and February 1992. There were 44 men, and the mean age was 65 years. Forty-one patients (64%) had sustained a previous infarction. Overall, endarterectomy was performed on 76 vessels, and the right coronary system was involved in 46 (61%).

RESULTS

The postoperative infarction rate was 5%. Incomplete occlusion ( < 90% stenosis) of the endarterectomized vessel significantly increased the risk of infarction (p < 0.05). There were two early deaths (3%). The mean follow-up was 46 months. Clinically, 91% of the survivors were angina free, and 80% had no symptoms of heart failure at the time of follow-up. Left ventricular function had improved in 36% of those restudied (5/14). A total of 17 recatheterizations were done at a mean interval of 19 months after operation. The endarterectomy graft patency rate was 80% (16/20) compared with 78% (28/36) for conventional grafts ( p = not significant). The actuarial survival rates were 89% and 71% at 1 year and 5 years, respectively. A history of previous infarction was significantly associated with higher long-term mortality (p < 0.02).

CONCLUSIONS

Overall, these results demonstrate that in modern cardiac surgery, coronary endarterectomy is safer than previously thought and can be used effectively to achieve complete revascularization in selected patients.