Ocular manifestations of keratitis-ichthyosis-deafness (KID) syndrome.

OBJECTIVE: Keratitis-ichthyosis-deafness (KID) syndrome is a rare congenital ectodermal dysplasia characterized by the association of hyperkeratotic skin lesions, moderate to profound sensorineural hearing loss and vascularizing keratitis. Mutations in the GJB2 gene coding for connexin 26, a component of gap junctions in epithelial cells, have been observed in several KID patients. Variable ocular manifestations of the disease in 3 patients with molecular genetically confirmed KID syndrome are reported. DESIGN: Retrospective case series. METHODS: Clinical examination and molecular genetic analysis for mutations in the GJB2 gene were performed in 3 patients with KID syndrome ages 5, 13, and 41 years. RESULTS: Visual acuity ranged from normal to severe visual loss. The ocular signs included loss of eyebrows and lashes, thickened and keratinized lids, trichiasis, recurrent corneal epithelial defects, superficial and deep corneal stromal vascularization with scarring, keratoconjunctivitis sicca, and, in one patient, presumed limbal insufficiency. Whereas ocular surface integrity could be maintained with artificial tears in one patient, and an epithelial defect healed under conservative treatment in the second patient, multiple surgical procedures including superficial keratectomies, limbal allograft transplantation with systemic immunosuppression, amniotic membrane transplantation, lateral tarsorrhaphies, and lamellar keratoplasty could not preserve useful vision in the third patient. CONCLUSIONS: KID syndrome may affect the ocular adnexae and surface with variable severity independent of the age of the patient. Lid abnormalities, corneal surface instability, limbal stem cell deficiency with resulting corneal complications, and dry eye are the main ocular manifestations.

[New automated microkeratome for trepanation of lamellar keratoplasty]. / Neues automatisiertes Mikrokeratom zur Trepanation lamellärer Keratoplastiken. Erste Erfahrungen.

BACKGROUND/PURPOSE: Lamellar keratoplasty is an established therapy of corneal pathologies without endothelial involvement and the lack of endothelial rejection is one of the major advantages compared to penetrating keratoplasty. The major disadvantages of manually prepared lamellar corneal grafts are the limited mechanical and optical quality but the automated lamellar therapeutic keratoplasty system ALTK (MORIA) is intended to overcome these disadvantages. The purpose of this preliminary work is to investigate histologically and in clinical cases, if the ALTK system can achieve this aim. PATIENTS AND METHODS: Corneas from two human donors were cut with a 300 microns trephine. After fixation, the stromal bed and the excised cup of one specimen were stained with PAS and examined by light microscopy and the other specimen was analyzed by scanning electron microscopy. In addition, follow-up data of two patients who received such a lamellar graft are reported for the first 9 and 7 months postoperation, respectively. RESULTS: The lamellar cut of homogeneous depth revealed only minor stromal trauma. Both clinical cases demonstrated only minimal interface haze during follow-up. Despite a remarkably clear cornea, visual acuity improved only slowly because the precise lamellar cut tended to partially reproduce any preexisting irregular astigmatism. CONCLUSIONS: The ALTK system simplifies and standardizes the trephination of lamellar corneal grafts but a longer follow up is necessary with respect to visual development and preservation of a clear graft.

Amniotic membrane inlay and overlay grafting for corneal epithelial defects and stromal ulcers.

OBJECTIVES: To determine the effect of amniotic membrane transplantation (AMT) on persistent corneal epithelial defects (PEDs) and to compare the efficacy between inlay and overlay techniques. METHODS: Thirty patients (30 eyes) underwent AMT for PED. The use of AMT was restricted to patients in whom all previous measures, including bandage contact lens and tarsorrhaphy, had failed. The amniotic membrane was placed on the surface of the cornea in overlay (group A) or inlay (group B) fashion. RESULTS: The PED healed after the first AMT in 21 eyes (70%) within an average of 25.5 days after surgery and recurred in 6 eyes (29%). Among the 22 eyes treated with an overlay AMT (group A), the PED healed after the first AMT in 14 eyes (64%) within an average of 24.5 days and recurred in 4 eyes (29%). Among the 8 eyes treated with an inlay AMT (group B), the PED healed within an average of 27.4 days after AMT, which did not statistically significantly differ from group A (P = .72). The PED healed after the first AMT in 7 eyes (88%) and recurred in 2 (29%) of 7 eyes. CONCLUSIONS: The AMT can be helpful in the treatment of PED in which all other conventional management has failed. However, the success rate in our study was not as high as that previously reported, and our results showed a high incidence of recurrences of epithelial defects. We did not find any difference between overlay and inlay techniques in terms of healing time and recurrence rate.

Central corneal thickness measurement with a retinal optical coherence tomography device versus standard ultrasonic pachymetry.

PURPOSE: To demonstrate the capability of a standard, commercially available optical coherence tomography device (originally designed to measure retinal thickness) to image the human cornea in vivo and to measure central corneal thickness (CCT) in normal and edematous corneas. The intrapatient precision and interpatient variability of this novel application was compared to standard ultrasonic pachymetry. Also, the correlation of both methods was investigated. METHODS: CCT measurements using optical coherence tomography (OCT) and ultrasonic pachymetry (PACH) were obtained in 36 normal eyes and 16 eyes with corneal edema. RESULTS: Direct in vivo imaging of the cornea and measurements of CCT by OCT could be performed in all eyes. In normal subjects, CCT(OCT) was 530+/-32 microm and CCT(PACH) was 581+/-34 microm. The two methods showed a highly significant correlation with a standardized regression coefficient of 0.988. The difference between both methods was constant over the range of CCT (mean difference, 49.4+/-5.9 microm). The mean intrapatient SD of CCT measurements was 4.90 microm and 4.96 microm for OCT and PACH, respectively. In patients with corneal edema, mean CCT(OCT) was 601+/-59 microm, and mean CCT(PACH) was 667+/-68 microm. The difference between the two techniques increased slightly with increasing corneal edema (mean difference, 66.9+/-10.9 microm). CONCLUSION: Imaging of the human cornea can be performed by a standard retinal OCT device, and OCT measurement of CCT shows excellent correlation to values obtained by PACH, giving similar readings separated by a constant difference. In corneal edema, the difference between the two methods is additionally increased, but continues to demonstrate excellent consistency.

Corneal manifestations of X-linked ichthyosis in two brothers.

PURPOSE: To report the unusual manifestation of X-linked ichthyosis in two brothers. METHODS: Leukocyte separation and sterylsulfatase assay are performed to show the deficiency of sterylsulfatase. RESULTS: Two brothers presented in our clinic with cutaneous alterations consistent with X-linked ichthyosis. Ocular examination disclosed fine, flour-like, punctate, evenly, and diffusely distributed opacities of the posterior corneal stroma, close to Descemet membrane in both patients. In one patient, superficial, small, granular opacities were detected. They were gray in color and seemed to involve the epithelium and the subepithelial and anterior stromal layers. In both patients, the deficiency of sterylsulfatase could be shown and confirmed the diagnosis. CONCLUSIONS: Flour-like opacities in the posterior stroma have been shown to be a common manifestation of X-linked ichthyosis. Though the underlying biochemical defect in X-linked ichthyosis has been discovered, the question of how these opacities develop is still a subject of debate. Subepithelial stromal keratopathies or epithelial irregularities are uncommon and are rarely described in the literature. The superficial corneal changes seen in one of our patients are unusual and are not similar to those reported by other authors.

Ex vivo phosphorus magnetic resonance spectroscopy on eye bank corneas and corneal metabolic health.

BACKGROUND: Since a potential exists for untoward effects on the cornea from the high magnetic fields and radio-frequency energies, and the further manipulation required for phosphorus-31 magnetic resonance spectroscopy (31P-MRS), we determined the effects of this technology on tissues using paired human corneas (n = 4) meeting criteria acceptable for transplantation. METHODS: Slit-lamp biomicroscopy, pachometry, specular microscopy, and redux fluorophotometry were performed on all corneas. One cornea of each pair was examined (< 30 min) by 31P-MRS. Following 31P-MRS, slit-lamp biomicroscopy, pachometry, and redox fluorophotometry were again performed. RESULTS: Data tabulated included the 31P energy modulus (1.37 +/- 0.28), the ATP/Pi (2.92 +/- 0.59) and SP/Pi (0.76 +/- 0.04) ratios, and the intracorneal pH (7.24 +/- 0.09). CONCLUSION: Since there were no significant differences in slit-lamp biomicroscopy, endothelial density and morphometry, cell counts, and pachometric and redox fluorophotometric measurements between corneas of each pair before and after 31P-MRS analysis, it was concluded that there was no detectable metabolic damage secondary to such analysis. This study suggests that MRS analysis of human eye-bank tissues does not damage the cornea metabolically and may provide a practical evaluation of the health of the cornea at the biochemical level.

Non-invasive assessment of the donor corneal endothelium using ocular redox fluorometry.

AIMS: To investigate the usefulness of ocular redox fluorometry for evaluating donor corneal endothelial viability. METHODS: Corneas from 42 recipients of penetrating keratoplasty and four donor corneas were examined by ocular redox fluorometry. Autofluorescence from reduced pyridine nucleotides (PN) and oxidised flavoproteins (Fp) of the human corneal endothelium were measured non-invasively, and the PN/Fp ratio was used as a tissue metabolic indicator. Specular microscopy and electron microscopy were also performed. RESULTS: Both the quality of specular microscopic image and the PN/Fp ratio were significantly correlated with the degree of corneal endothelial damage determined by histological examination. Corneas with poor specular microscopic image showed significantly decreased PN/Fp ratio compared with corneas with good or fair specular images (p = 0.041 and 0.027, respectively). The PN/Fp ratio increased in corneas with mildly damaged endothelium but decreased in corneas with severely damaged endothelium determined by histological examination. Evaluation of corneal endothelium by combination of specular microscopy and ocular redox fluorometry showed excellent association with that of histopathological examination (p < 0.0001). CONCLUSION: Ocular redox fluorometry is useful for assessing donor corneal endothelial viability. Combination of ocular redox fluorometry and specular microscopy may increase the ability of donor cornea selection.

Scanning electron microscopy of the early host inflammatory response in experimental Pseudomonas keratitis and contact lens wear.

Because contact lens wear causes changes in tear film and corneal metabolism and can render the cornea susceptible to bacterial invasion, we examined the role of contact lens wear in Pseudomonas aeruginosa (P. aeruginosa) keratitis and its relation to the early defense mechanism, specifically whether the acute polymorphonuclear leukocyte (PMN) response is altered by contact lens wear. Thirty-three rabbit eyes were examined in an experimental model for P. aeruginosa keratitis. The development of bacterial invasion and PMN migration into the wound was studied during various time intervals in either the presence or absence of a soft hydrogel contact lens (SCL). Scanning electron microscopy revealed massive PMN accumulation in the P. aeruginosa-inoculated corneas without SCL and some, but distinctively fewer, PMNs in the bacteria-inoculated eyes with SCL. These observations demonstrate that P. aeruginosa inoculation evokes massive PMN reaction and suggests that SCL wear actually delays this early host inflammatory response. Thus, SCL wear seems to act as a barrier for the PMNs that presumably derive from the tear film.

Penetrating keratoplasty and anterior segment reconstruction for severe ocular trauma.

The principles for management of acute ocular trauma are also applicable to the subsequent reconstruction of the anterior segment. As with the primary repair of ocular trauma, meticulous anatomical restoration during reconstructive surgery minimizes secondary complications and enhances the visual prognosis. Anterior segment reconstruction may then involve procedures such as stripping of corneal pannus, removal of lens and vitreous remnants, iris and angle reconstruction, intraocular lens implantation, and penetrating keratoplasty. A total of 39 consecutive cases of severe ocular trauma, which had undergone penetrating keratoplasty and anterior segment reconstruction, were evaluated for visual outcome, graft survival, and secondary complications. Post-operatively, 49% of eyes achieved > 20/100 as compared with 10% before surgery, and 72% improved by at least two Snellen lines. In all, 31 (80%) initial keratoplasties remained clear, as did all 4 subsequently regrafted corneas, for an overall keratoplasty success rate of 90%. Elevated intraocular pressure occurred postoperatively in 18 eyes (46%), and among these, 10 of 13 eyes (77%) had preoperative glaucoma, whereas 8 of 26 (31%) did not (P < 0.015). Peripheral anterior synechiae could be anatomically corrected at surgery in 80% of cases (24 of 30 eyes). Thus, despite major trauma and a high prevalence of glaucoma, both the visual and the anatomical improvements were highly satisfactory and without severe complications.

Increased interleukin-1 activity in the injured vitamin A-deficient cornea.

Injury to a vitamin A-deficient cornea leads to severe acute inflammation often culminating in ulceration. We report on possible regulatory mechanisms involved in the pathogenesis of corneal inflammation in vitamin A deficiency. Thymocyte comitogenic assay and interleukin (IL)-6 induction in corneal fibroblasts have shown that thermally injured and mechanically abraded vitamin A-deficient rat corneas produce much higher levels of an IL-1-like factor as compared with uninjured or injured, normal control corneas. This was confirmed by antibody capture enzyme immunoassay, which detected high levels of IL-1 alpha and IL-1 beta in injured vitamin A-deficient corneas. To our knowledge this is the first report describing the induction of IL-1 in the vitamin A-deficient cornea by thermal and mechanical injuries. When mechanically injured corneas were screened for chemotactic activity, they were found to contain significantly higher levels of a chemoattractant as compared with similarly injured, normal control corneas. Chemotactic activity [expressed as a percentage of a known chemotactic tripeptide, formyl-methionyl-leucyl-phenylalanine (fMLP), found in medium harvested from vitamin A-deficient corneas] averaged 58.8 +/- 8.9% (SEM) as compared with 12.6 +/- 5.4% in medium conditioned by normal corneas. Checkerboard analysis confirmed that the activity in vitamin A-deficient cornea conditioned medium was chemotactic and not chemokinetic. These results demonstrate a correlation between IL-1 levels and severity of inflammation in the injured vitamin A-deficient rat cornea.

Increased gelatinolytic and caseinolytic activity in the thermally injured, nutritionally compromised rat cornea: detection of a 27-kDa lymphoreticular cell-associated caseinase.

This study assesses the impact of various forms of injury on matrix degrading enzymes in nutritionally compromised rat corneas. In vitamin A-deficient (nutritionally compromised) and normal control corneas, in vivo or ex vivo mild mechanical abrasion did not appreciably alter the activity of either the 65-kDa or the 92-kDa gelatinases. In contrast, after thermal injury, while no appreciable change was detected in activity associated with the 65-kDa gelatinase in either vitamin A-deficient or normal control corneas, 92-kDa gelatinolytic activity was consistently higher in corneas from both groups, although activity associated with nutritionally compromised corneas was much higher. In these corneas, thermal injury also induced the expression of two high molecular weight (approximately 130-kDa and 225-kDa) gelatinases and a 27-kDa caseinase. While gelatinases were totally inactivated by inhibitors of metalloproteinases such as 1,10-phenanthroline and Galardin MPI, the 27-kDa caseinase showed considerable susceptibility to a mixture of serine protease inhibitors (aprotinin, dichloro-isocoumarin and pA-PMSF [(4-amidino-phenyl)-methane-sulphonyl fluoride]. Furthermore, unactivated-lymphoreticular cells from either nutritionally compromised or normal control animals contained a 24- and 27-kDa caseinase, however most of the activity was due to the 24-kDa caseinase. In contrast, glycogen-activated lymphoreticular cells contained a preponderance of the 27-kDa caseinase. Activated-lymphoreticular cells also expressed 92-kDa, 130-kDa and 225-kDa gelatinases. The presence of low molecular weight caseinases in lymphoreticular cells implicates them as the source of these enzymes.(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized trial of intraocular lens fixation techniques with penetrating keratoplasty.

PURPOSE: Pseudophakic corneal edema is the principal indication for penetrating keratoplasty in the United States. Currently, three techniques of intraocular lens (IOL) fixation during penetrating keratoplasty for this condition are commonly used--flexible anterior chamber IOL (AC IOL) implantation, iris suture fixation of a posterior chamber IOL (PC IOL), and transscleral suture fixation of a PC IOL. This study represents the first prospective, randomized comparison of these three techniques. METHODS: One hundred seventy-six consecutive patients with pseudophakic corneal edema who underwent penetrating keratoplasty with IOL exchange were randomized to one of the three implantation techniques. Standardized evaluations were performed at baseline and at 6, 12, and 18 months postoperatively. Life-table analysis provided cumulative risk estimates for specific complications. RESULTS: Randomization produced comparable groups at baseline. The cumulative risk of macular edema was significantly less for the iris fixation cohort than for either the AC IOL or scleral fixation group. A complications index was constructed based on the major adverse outcomes of glaucoma escalation, cystoid macular edema, IOL dislocation, and graft failure. A significantly lower risk of complication was found for iris compared with scleral fixation of PC IOLs. CONCLUSION: The authors conclude that transscleral fixation of the PC IOL at the time of penetrating keratoplasty for pseudophakic corneal edema is associated with a greater risk of adverse outcome than iris fixation of a PC IOL.

Effect of vitamin A deficiency on the adhesion of rat corneal epithelium and the basement membrane complex.

PURPOSE: To understand the underlying mechanisms responsible for the easy removal and sloughing of corneal epithelium in vitamin A deficiency. METHODS: An animal model of vitamin A deficiency, the vitamin A-deficient rat (A-rat), transmission electron microscopy, computer-assisted morphometric analysis and indirect immunofluorescence were used to study the adhesion of rat corneal epithelium to its basement membrane with emphasis on structure and molecular composition of the anchoring structures such as the hemidesmosome and bullous pemphigoid antigen. RESULTS: Transmission electron microscopy resolved numerous microseparations of the basal epithelial cell membrane from the basement membrane with intervening segmental basement membrane duplications and electron dense deposits. Morphometric analysis disclosed a statistically significant reduction in the frequency and size of hemidesmosomes. Four weeks after supplementing the diet with retinyl acetate (700 micrograms/week), significant reversal of these same structural abnormalities could be detected. Immunofluorescence staining for bullous pemphigoid antigen, a component of the adhesion complex, showed intense staining of the basal epithelial cytoplasm but weak and discontinuous staining of the basement membrane. Weak staining for laminin was also evident in A- corneas. In contrast, normal corneas displayed no cytoplasmic staining for bullous pemphigoid antigen and intense staining of the basement membrane for bullous pemphigoid antigen and laminin. CONCLUSIONS: The authors propose that structural abnormalities of the epithelial basement membrane complex are responsible for the observed loose epithelial adhesion and sloughing, as well as other known abnormalities of healing in the vitamin A-deficient rat cornea.

In vitro propagation of human ocular surface epithelial cells for transplantation.

PURPOSE: To examine the possibility that ocular surface epithelial cells might be grown in culture for use as grafts. METHODS: The proliferative capacity of epithelial cells cultured from the conjunctiva, limbus, and central cornea of normal human eyes was compared. Single cells disaggregated from approximately 1 mm2 biopsy specimens were serially cocultured with lethally irradiated mouse 3T3 fibroblasts. To study the cells' ability to reform a stratified epithelium, confluent limbal cultures were released as an intact cell sheet with the enzyme Dispase and transplanted to a dermal connective tissue bed in nude mice. Attachment and differentiation properties of the reconstituted epithelium were examined immunohistochemically. RESULTS: Central corneal epithelial cells could not be propagated; they senesced in first or second passage. In contrast, limbal epithelial cells exhibited a substantial (i.e., mean of 23 population doublings) and conjunctival cells a moderate (i.e., mean of 11 population doublings) proliferative capacity. Within 4 days of transplantation to the nude mouse dermis, cultured limbal epithelial cells formed an epithelium 5-6 cell layers thick. The epithelium adhered firmly to the graft bed, and deposition of the basement membrane and anchoring fibril protein collagens IV and VII and laminin was detectable immunohistochemically. The transplanted epithelium displayed limbuslike compartmental expression of keratins K3, K13, and K19, and of the enzyme enolase. CONCLUSIONS: These results support the concept that corneal epithelial stem cells are located in the limbus and indicate that cultured autologous limbal cells may function as grafts to permanently restore the corneal epithelium after severe ocular surface injury.

Cleavage and activation of corneal matrix metalloproteases by Pseudomonas aeruginosa proteases.

PURPOSE: To examine the effect of Pseudomonas aeruginosa on the expression of corneal matrix metalloproteases and the effect of its proteases on activation of corneal matrix metalloproteases in vitro. METHODS: Rat corneas and human corneal fibroblasts were co-cultivated with two different strains (RPS & 599A) of P. aeruginosa and one strain of Staphylococcus aureus, and the conditioned media were analyzed for proteolytic activity by gelatin and casein zymography. Human corneal fibroblast-conditioned medium was incubated with that from either strain of P. aeruginosa and was analyzed in a similar manner. RESULTS: Normal rat corneas in organ culture produce a 65 kDa gelatinase (inactive matrix metalloprotease-2), whereas thermally injured rat corneas additionally produce gelatinases with molecular masses of 92 kDa (inactive matrix metalloproteases-9) and > 200 kDa. Matrix metalloprotease-2 is also detected in human corneal fibroblast-conditioned medium. Although these matrix metalloproteases are no longer detectable when rat corneas or human corneal fibroblasts are co-cultured with two strains of P. aeruginosa for 48 hr, a 58 kDa gelatinase fragment appears in earlier stages of co-culture. In contrast, S. aureus does not affect matrix metalloprotease-2. The 58 kDa fragment is also evident by incubating human corneal fibroblast-conditioned medium with that from either strain of P. aeruginosa. Conditioned medium from the RPS strain, which produces both elastase and alkaline protease, is more effective in cleaving matrix metalloprotease-2 than that from the 599A strain, which expresses mainly alkaline protease. CONCLUSION: The secreted inactive corneal matrix metalloprotease-2 is activated through limited proteolysis by pseudomonal proteases.

Anterior corneal disease of epidermolysis bullosa simplex.

We report the histopathological findings of the anterior cornea from a patient with skin biopsy-proven epidermolysis bullosa simplex. As seen with light microscopy, the cornea had a fibrocellular pannus deep to a thickened epithelial basement membrane. Transmission electron microscopy of the anterior cornea demonstrated a nonhomogeneous basal epithelial layer with abnormal attachment complexes to an irregular, multilaminar basement membrane. The findings of transmission electron microscopy of the bulbar conjunctiva were normal.

Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis.

Pseudomonas aeruginosa adherence in vitro to perfilcon A (ionic, 71% H2O) extended wear soft contact lenses--both new and after 7 days of continuous wear on closed rabbit eyes--was found to be related directly to the bacterial concentration in the contaminating solution. Thirty rabbits wore perfilcon A lenses for 7 days with complete lid closure to mimic contact lens overwear. After 7 days, conjunctival cultures showed no growth of pathogens, but all corneas had developed epithelial cell exfoliation and/or epithelial defects and stromal edema. The lenses were then incubated in various concentrations (10(7), 10(6), 10(5), 10(4), and 10(2) colony-forming units per milliliter or saline control; n = 5/group) of P. aeruginosa suspensions and replaced on their respective corneas with tarsorrhaphies for an additional 48 h. By day 9, corneal thickness had increased significantly, and P. aeruginosa keratitis had developed in 13 of 25 bacterially exposed eyes but not in 5 control eyes. Although with decreasing P. aeruginosa concentration the prevalence of ulcerative microbial keratitis also decreased, the initial concentration of bacteria or the initial extent of soft contact lens-induced corneal damage had no influence on the ultimate clinical severity of the disease.