R. Guerra

Normal intraocular pressure in children

The age-related trend values and the normal intraocular pressure (IOP) increase curve from birth through the 16th year of life were studied in 460 subjects with a noncontact tonometer (Keeler Pulsair, Keeler, Ltd, Windsor, Berks, UK). Much lower values than in adults were recorded in subjects up to the age of 3 or 4 years. This finding leads us to believe that in the treatment of infantile glaucoma IOP should be kept within the age physiologic levels, in an attempt to prevent visual field loss and optic atrophy.

Congenital nasolacrimal duct obstruction : Therapeutic management

PURPOSE Congenital nasolacrimal duct obstruction is a common condition, and its diagnosis must be based more on regular in-time epiphora than mattering. The purpose of this study is to better define the diagnostic criteria and therapeutic strategy. METHODS We have retrospectively evaluated 1563 subjects treated from 1990-1997 at the Pediatric Ophthalmological Service of Modena University Eye Clinic. The mean age at first examination was 5.7 months. According to symptoms and age, patients were treated with antibiotic therapy, office probing, or general anesthesia probing. Recovery was confirmed only after a 3-month symptom-free period. RESULTS More than 29% of patients recovered spontaneously or with topical antibiotic therapy. Office probing reduced the number of patients who needed a general anesthesia probing (from 62.97% from 1990-1993 to 33.61% from 1994-1997). In the period from 1994-1997, we changed the technique and especially the age of patients, obtaining a clearing of the obstruction in about 86% of cases compared with a 39% rate in the earlier period. Since 1994, in cases of general anesthesia probing, we have used a midazolam and ketamine anesthesiologic technique that has reduced risks and increased parental satisfaction and cost-effectiveness. Also, our data show that age at first attempt highly influenced probing failure rate. CONCLUSION If the first ophthalmologic examination is precocious and correctly timed, the possibility of curing the patient using the simplest method is increased. Better results can be obtained with cooperation among pediatricians, ophthalmologists, and anesthesiologists.

Ultrastructural Localization of Gelsolin in Lattice Corneal Dystrophy Type I

In the light of recent studies into lattice corneal dystrophies, with particular reference to gelsolin immunoreactivity, the authors set out to determine the ultrastructural localization of gelsolin molecules in lattice corneal dystrophy type I. Immunoelectron microscopy with a monoclonal antibody against the COOH-terminal of the native gelsolin molecule (clone GS-2C4) was used to compare antigelsolin reactivity in normal and dystrophic corneas. A gelsolin-like protein was observed at the level of the rough endoplasmic reticulum in both epithelial and endothelial cells, together with mild positive staining in stromal keratocytes of normal corneas; increased keratocytic immunoreactivity with positive staining within and/or around corneal amyloid deposits was revealed in dystrophic corneas. Observed intra- and extracellular immunoreactivity suggests that amyloid deposition may induce gelsolin synthesis; this actin-related protein could be involved in the rearrangement of corneal stroma in lattice corneal dystrophy.

Book Review · Livre nouveau · Buchbesprechung

This book deals with animal studies on corneal graft rejection. The introduction presents the current state of knowledge of allograft reaction after experimental keratoplasty and focuses on immunomodulated therapy with encapsulated monoclonal antibodies (mAb) in local application. In the second chapter, the goals and reasons for a study on the prevention of allograft rejection by local treatment with mAb are given in the form of four questions: (1) can locally applied CD4 mAb affect graft reaction after penetrating keratoplasty? (2) are liposome-incorporated CD4 mAb more effective? (3) do locally applied CD4 mAb have a systemic effect? (4) does the recipient react systemically against graft antigens and are in vitro tests meaningful for clinical grafts? Materials, methods and results are clearly described in the third and fourth chapters. In an experimental model of penetrating keratoplasty in rat eyes, anti-CD4 mAb were injected subconjunctivally or applied as drops in two different forms of administration selected for free mAb in a first test series and liposome-encapsulated mAb in a second. The results of liposome-encapsulated mAb application showed a declining incidence of immunologic graft reactions after subconjunctival injection and also after drop application. The controls showed no effects. A systemic effect on CD4+ lymphocytes could be excluded by flow cytometry. The cytotoxic T lymphocyte activity tested by antigen-specific cytotoxic T lymphocyte in vitro tests was significantly elevated after allograft reactions as an indication of specific sensitization. In contrast to this, no delayed-type hypersensitivity response was observed in the present study. These results are discussed in detail in the fifth chapter. In summary, the results described in this book open up new perspectives for preventing allograft reactions after keratoplasty by local application of liposome-encapsulated specific mAb. These exciting animal results should proceed to clinical trials in the near future.

Epikeratophakia: histopathological and cultural study

SummaryThree epikeratoplasty buttons (one aphakic and two myopic) prepared by the freeze technique were removed two to nineteen months after surgery. A complete morphological and immunohistochemical study was performed on these buttons in order to gain insight into the reasons for epikeratophakia failure. Histopathological studies with light microscopy and scanning and transmission electron microscopy were performed. All three cases showed an anomalous process of re-epithelialization: in the first, the epithelium over the donor cap was almost completely absent, with many abnormalities; in the second, the epithelium was irregular, with a varying number of cell layers and poor adhesion between cells; in the third, the development of an epithelial cyst between the tissue lens and the cornea of the host caused the failure of the epikeratoplasty.The specimens were cultured ‘in vitro’ and the cells grown typed for HLA antigens. The antigen panel was the same as that of the host. Immunohistochemistry showed CD3- and CD8-positive cells in the stroma, proving the activity of T-suppressor lymphocytes in a cell-mediated immunoreaction.