Lora Longanesi

Comparison of Deep Sclerectomy with Implant and Combined Glaucoma Surgery

To evaluate the efficacy of combined glaucoma surgery, 42 glaucomatous patients were randomly divided into two groups: deep sclerectomy with implant (DS) alone was performed in 21 patients, and combined deep sclerectomy and phacoemulsification (PDS) was performed in the other 21 patients. Follow-up was carried out at regular intervals for 12 months. A comparative study on intraocular pressure (IOP) was designed. Although further study is needed, PDS appears to have better postoperative long-term results in IOP control than DS alone.

Quantitative Clinical Anatomy of the Human Cornea in vivo

The cornea is the most important refractive element in the human ocular system, providing approximately two thirds of the eyes refractive power in the nonaccommodative state. The methods of description and analysis of the corneal anatomy in vivo continue to be refined thanks to the increased interest aroused by the advent of corneal refractive surgery, which aims to modify the dioptric power of the ocular system by altering the thickness and the radius of curvature of the cornea. In the present study we report quantitative morphometric data of corneal thickness and the radius of curvature of the anterior surface of the cornea obtained in vivo from normal human subjects using ultrasonic pachymetry and computer-assisted topographic videokeratoscopy. We found a highly significant statistical correlation in the distribution of corneal thickness and the radius of curvature of the anterior surface of the cornea along the principal corneal meridians (horizontal and vertical meridians) and within three different concentric zones of the cornea, 2, 4 and 6 mm, respectively, from the geometric center along the principal meridians. Correlation was also found for the same morphometric parameters between the right and the left eye. By contrast, no correlation was found between corneal thickness and the radius of curvature of the anterior surface of the cornea. These findings suggest that the adult human cornea is a structure characterized by a highly ordered tridimensional architecture and symmetry and that a specific distribution of corneal thickness and the radius of curvature of the anterior corneal surface along the principal meridians may be essential for the refractive function of the human corneal diopter in vivo.

Surgically induced astigmatism after manual extracapsular cataract extraction or after phacoemulsification procedure

Astigmatic changes in three series of cataract surgical procedures were compared. The first two series comprised eyes having a manual extracapsular cataract extraction (ECCE) through a 12.0 mm or 8.0 mm incision and implant of a PMMA posterior chamber lens. The third series comprised eyes having phacoemulsification through a scleral pocket and implant of a PMMA posterior chamber lens. Preoperative keratometry measurements and corneal topography maps were compared with those obtained two days, one week, one, three and six months postoperatively. The keratometry measurements, obtained with computerized videokeratography, revealed: on day 2, 4.89 D (1st series), 3.95 D (2nd series), 2.66 D (3rd series); one week, respectively 4.46 D, 3.51 D and 2.14 D; one month, 0.65 D, 0.53 D and 0.05; three months, 1.44 D, 0.35 D and 0.36 D; six months, 1.36 D, 0.42 D and 0.48 D. The surgically-induced cylinder at three months was four times greater in the manual ECCE 12.0 mm incision series than in the phacoemulsification series. However, by six months all differences were markedly reduced. The results add to the growing evidence that the phacoemulsification procedure produces less astigmatism and more rapid visual rehabilitation than the manual ECCE procedure. Topographic analysis showed much less corneal steepening after phacoemulsification than after manual ECCE. However, all three surgical procedures offered satisfactory clinical results.

Comparison of the clinical performance of Healon 5 and Healon in phacoemulsification.

Purpose Healon 5 is a high-molecular-mass fraction of sodium hyaluronate. Its density endows it with a number of viscoelastic characteristics. In this prospective, randomised clinical study we compared the performance of Healon 5 and Healon in phacoemulsification. SETTING. Institute of Ophthalmology, University of Modena and Reggio Emilia, Italy. Methods Two groups of patients underwent phacoemulsification and intraocular lens (IOL) implantation. In the first 27 patients Healon 5 was used as viscoelastic substance during surgery, and in the second 27 Healon was used. The surgeons subjective comments on the performance of these viscoelastic agents were recorded at the different steps of surgery: injection, capsulorhexis, phacoemulsification, IOL implantation, removal of viscoelastic agent and trasparency throughout the operation. The surgeons overall impression of the viscoelastics during the whole operation was noted. Tonometry and endothelial cell count were performed in all patients before and after operation. Results There was no statistical difference between the two groups as regards visual acuity, ocular pressure and endothelial damage. Healon 5 showed excellent ability to maintain the anterior chamber during capsulorhexis, phacoemulsification and IOL implantation. Removal time with Healon 5 was not appreciably longer than Healon. Conclusions Healon 5 emerges as a very interesting viscoelastic substance. Visibility is better if the anterior chamber is filled completely. Removal is easier if it is aspirated while moving the irrigation aspiration tip with circular movements over the top and around the border of the IOL.

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.