Martin Grueterich

Long-term outcome of keratolimbal allograft with or without penetrating keratoplasty for total limbal stem cell deficiency☆

PURPOSEnTo evaluate the long-term outcome of ocular surface reconstruction, including keratolimbal allograft (KLAL) and amniotic membrane transplantation (AMT) with or without penetrating keratoplasty (PKP), in patients with nonambulatory vision secondary to total limbal stem cell deficiency (LSCD).nnnDESIGNnRetrospective, non-comparative interventional case series.nnnPARTICIPANTSnThirty-nine eyes in 31 consecutive patients with total LSCD, as defined by impression cytology, who had a preoperative best-corrected visual acuity of less than 20/200 and a minimum follow-up of 12 months. Patients were divided into three groups: group 1 (16 eyes) with chemical burns, group 2 (9 eyes) with Stevens-Johnson syndrome (SJS), and group 3 (14 eyes) with other causes of LSCD, including ocular cicatricial pemphigoid, atopic keratoconjunctivitis, and aniridia.nnnINTERVENTIONnAll patients underwent KLAL and AMT by one surgeon (SCGT). If needed, PKP was performed at the same surgical setting using tissue from the same donor.nnnMAIN OUTCOME MEASURESnCumulative rates of survival of ambulatory vision (> or = 20/200), survival of KLAL, survival of PKP, and incidence of complications.nnnRESULTSnFifty-three KLAL with AMT procedures were performed in 39 eyes, of which 23 eyes received simultaneous PKP at the time of the first KLAL. The mean follow-up was 34.0 +/- 21.5 months (range, 12-117.6). The mean period of ambulatory vision was 23.9 +/- 20.9 months (range, 0-104). The overall survival of ambulatory vision was 53.6% at 3 years and 44.6% at 5 years. The survival of ambulatory vision was significantly worse in SJS compared with other causes (67%, 81%, and 92% for groups 1, 2, and 3, respectively; P = 0.06 for group 1 versus 2, P = 0.0008 for group 1 versus 3). KLAL performed alone resulted in higher survival of ambulatory vision at 2 years (86.1% +/- 9.1%) compared with KLAL with PKP (46.9% +/- 10.6%, P = 0.100). The survival of PKP was significantly worse in SJS compared with the other causes (20.0% +/- 17.9% compared with 55.6% +/- 11.7%, respectively, P = 0.028). After 2 years, the survival of the second KLAL was better than that of the first: 68.2% +/- 15.4% compared with 27.3% +/- 13.4%, respectively (P = 0.041).nnnCONCLUSIONSnAmbulatory vision for a period of more than 2 years can be achieved by KLAL with or without PKP in eyes with severe ocular surface disorders caused by total LSCD. However, a progressive decline of the visual outcome and graft survival is evident with time. Performing PKP simultaneously with KLAL may be associated with a less favorable outcome. The failure of KLAL is associated with the loss of donor cells in the recipient. Augmentation of ocular surface defense is essential in securing the success of KLAL and PKP. Future modifications of the surgical procedure and of the immune suppressive protocols may improve survival of the allogeneic grafts and the final visual outcome.

The challenge of dry eye diagnosis

The currently available methods for the diagnosis of dry eye are still far from being perfect for a variety of reasons. This review attempts to highlight the advantages and disadvantages of both traditional tests (such as Schirmer’s test, break-up time and ocular surface staining) and innovative noninvasive procedures, including tear meniscus height measurement, corneal topography, functional visual acuity, tear interferometry, tear evaporimetry and tear osmolarity assessment.

AMNIOTIC MEMBRANE TRANSPLANTATION FOR BULLOUS KERATOPATHY IN EYES WITH POOR VISUAL POTENTIAL

Purpose: To evaluate the long‐term outcomes of epithelial debridement and amniotic membrane transplantation (AMT) for pain and discomfort relief in patients with symptomatic bullous keratopathy and poor visual potential. Setting: Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA. Methods: This retrospective study included 18 eyes (18 patients) with bullous keratopathy presenting with intractable pain or discomfort and poor visual potential. After epithelial debridement, all eyes had AMT with the basement membrane side up. During a mean follow‐up of 25.1 months ± 9.6 (SD) (range 12 to 45 months), pain relief, epithelial healing, and visual changes were analyzed. Results: Pain relief was obtained in 88% of patients. Sixty‐six percent of eyes had complete resolution of ocular discomfort starting soon after the first postoperative day. One eye had evisceration for persistent pain 10 months postoperatively. Corneal epithelial healing was complete in all except 1 eye. Remaining complaints included foreign‐body sensation (5%), tearing (11%), and photophobia (5%). Conclusions: Amniotic membrane transplantation was a safe, effective, and long‐lasting treatment modality for intractable pain associated with chronic bullous keratopathy in eyes with poor visual potential. It can be an alternative to conjunctival flaps for the long‐term management of patients with bullous keratopathy in whom corneal transplantation is not indicated. A comparison of the efficacy of AMT with that of other surgical procedures must be performed.

Idiopathic limbal stem cell deficiency.

PURPOSEnTo describe and to characterize the clinical findings and prognosis of patients with idiopathic limbal stem cell deficiency (LSCD).nnnDESIGNnRetrospective case series.nnnPARTICIPANTS/METHODSnWe reviewed records from seven patients whose LSCD had been diagnosed clinically and confirmed by impression cytology and in whom the cause of LSCD was never identified. A detailed history, clinical records, and results of slit-lamp biomicroscopy, photography, vital staining, and impression cytology were evaluated.nnnRESULTSnSix of seven patients (86%) were women, indicating a female predominance. Two patients were from the same family, whereas one other had a positive family history. Severe photophobia was noted in all patients and reduced vision in three patients. The main clinical findings included superficial vascularization, worse in the superior followed by the inferior and nasal cornea. The limbal regions showed a loss of limbal palisades of Vogt, and the adjacent peripheral cornea revealed an irregular and hazy epithelium with positive late fluorescein staining and the presence of conjunctival goblet cells by impression cytology. LSCD was bilateral in all patients but asymmetric in four. During a mean follow-up of 6.1+/- 3.8 years, the visual acuity decreased in both eyes of one patient after cataract extraction and in both eyes of two other patients without surgery. The process of conjunctivalization advanced in four patients (57%) and remained stable in three (43%) without surgical intervention.nnnCONCLUSIONSnIdiopathic LSCD is a rare and as yet poorly recognized clinical entity, and the findings reported herein may help explore how progressive loss of limbal stem cells occurs. Correct diagnosis of idiopathic LSCD is important so that the patient will not be subjected to unnecessary surgeries, which may actually severely worsen the clinical course.

Cleavage of corneal basement membrane components by ethanol exposure in laser-assisted subepithelial keratectomy.

Purpose: To determine the anatomic cleavage plane after exposure to 20% ethanol for approximately 20 to 25 seconds to create an epithelial flap in laser‐assisted subepithelial keratectomy (LASEK). Setting: Ocular Surface Research & Education Foundation, Miami, Florida, and Hermann Eye Center Refractive Surgery Center, Houston, Texas, USA. Methods: Immunofluorescence staining using monoclonal antibodies against laminin 5, collagen VII, and integrins &bgr;1 and &bgr;4 was performed to determine the anatomic location of the cleavage plane in an epithelial flap created by 20‐second exposure to 20% ethanol in cadaver eyes and in epithelial flaps obtained from LASEK patients. Results: Immunofluorescence staining to laminin 5 and integrin &bgr;4 was patchy in the lifted flap and the remaining corneal basement membrane. Immunostaining to collagen VII, the main component of anchoring fibrils, remained exclusively in the corneal bed. Immunostaining to integrin &bgr;1, present in the pericellular location of all epithelial cell layers, remained exclusively in the epithelial flap. This finding was consistent in cadaver corneas and LASEK epithelial flaps. Conclusion: The cleavage plane of the ethanol‐induced corneal epithelial flap is located between the lamina lucida and the lamina densa of the basement membrane, where integrin &bgr;4 interacts with laminin 5 to form hemidesmosomes.

Evaluation of interface quality in organ-cultured lamellar corneal transplants

Background With increasing numbers of lamellar keratoplasties, eye banks are challenged to deliver precut lamellar donor tissue. In Europe, the most common technique of corneal storage is organ culture which requires a deswelling process before surgical processing. The aim of this study was to investigate the influence of different deswelling times on the cutting plane quality after microkeratome-assisted lamellar dissection. Methods Eight paired donor corneas (16 specimens) not suitable for transplantation were organ cultured under standard conditions at the Eye Bank of the Ludwig-Maximilians Universität, Munich, Germany. Pairs of corneal buttons were analyzed during the deswelling process in dextrane-containing medium. While one cornea was cut at an early time point during the deswelling process and put back into deswelling medium thereafter, the partner cornea was completely deswollen and dissected after 72 hours. Specimens were then further processed for scanning electron microscopy. Surface quality was assessed both digitally using Scanning Probe Imaging Processing software, and manually by three blinded graders. Results The corneal buttons processed at the beginning of the deswelling process had a smoother surface when compared to the partner cornea that was cut at the end of the deswelling process. In our setting, no relevant difference was detectable between manual and automated microkeratome dissection. Conclusion For lamellar keratoplasty, organ-cultured corneas should be processed at an early stage during the deswelling process. We interpret the smoother dissection plane during early deswelling as a result of mechanical properties in a highly hydrated cornea.