Prevention of posterior capsule opacification using capsular tension ring for zonular defects in cataract surgery.

PURPOSE: To evaluate the incidence of secondary cataract in phacoemulsification and intraocular lens implantation using a capsular tension ring in case of zonular dehiscence. METHODS: Phacoemulsification using a double capsular tension ring and intraocular lens implantation was done in 65 eyes with cataract and severe zonular weakness. One year after surgery capsular opacities and fibrosis were detected in a double-blind examination. The results were compared with a control group of 36 eyes that did not have a capsular tension ring but had similar surgery. RESULTS: In the group with the capsular tension ring and implantation 7.7% of patients had moderate or severe posterior capsule opacification, compared with 36.1% in the control group. CONCLUSIONS: Capsular tension rings may influence the formation of capsule opacification.

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 surgeon's 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.

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.

Quantitative clinical anatomy of the human cornea in vivo. A morphometric study by ultrasonic pachymetry and computer-assisted topographic videokeratoscopy.

The cornea is the most important refractive element in the human ocular system, providing approximately two thirds of the eye's 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.

Cytologic diagnosis of Acanthamoeba keratitis. Report of a case with correlative study with indirect immunofluorescence and scanning electron microscopy.

We describe a case of Acanthamoeba keratitis in a 20-year-old woman who wore disposable soft contact lenses. The diagnosis was made initially on the basis of a periodic acid-Schiff-stained corneal smear and subsequently confirmed by scanning electron microscopy and immunofluorescence. The patient was successfully treated with a combination of 0.053% polyhexamethylene biguanide and miconazole. Cytologic study and culture of corneal scrapings is relatively painless and inexpensive and may therefore be used for successful diagnosis and follow-up.

Cytology of allergic conjunctivitis. Presence of airborne, nonhuman elements.

Two groups of patients suffering from allergic conjunctivitis (32 atopic, 33 nonatopic) were studied. Their conjunctival secretions were subjected to cytologic examination involving morphologic and semiquantitative evaluation. Account was taken of noncellular and nonhuman elements in the smears; they included mucus, Charcot-Layden crystals, pollen grains, vegetal fragments and fungi. In 12 cases scanning electron microscopy was used in conjunction with x-ray microanalysis to identify material of noncellular origin. Similar quantities of inflammatory cells were present in both groups, while epithelial cells, particularly goblet cells, were more numerous in the atopic than in the nonatopic group (21.8% versus 6%). Pollen grains, vegetal fragments and fungi were present in 18%, 55% and 12% of cases, respectively. Exfoliative cytology emerges as a valuable tool for the diagnosis of allergic conjunctivitis, while the presence of noncellular elements is of particular diagnostic significance.

Epikeratophakia: histopathological and cultural study.

Three 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.

[Screening of early color vision loss in diabetic patients]. / Dépistage des altérations précoces de la vision des couleurs chez les patients diabétiques.

Colour vision defects have been claimed to appear in diabetes before any retinopathy is visible. In the present study diabetic patients and non diabetic control subjects were screened with two different colour vision tests which include both red-green and blue-yellow parts, and are suitable for quantitative analysis of scores. The Lanthony 40 Hue test and the Tokyo Medical College--T.M.C. tables were used to assess colour vision in 106 diabetic (50 insulin dependent and 56 non insulin dependent) patients and in 99 non diabetic control subjects. Diabetic patients without visible retinopathy, familiar colour vision defects and/or lens changes, had significantly higher scores than control subjects in both eyes. The differences were more evident in non insulin dependent patients. Statistical analysis showed that early loss of colour vision was correlated with age and duration of diabetes for older patients, while correlation with glycosylated hemoglobin was moderately positive only for younger patients. Both tests (especially the Lanthony 40 Hue) resulted to be highly specific and could be used for the clinical study of colour vision losses in diabetic patients.

Photic maculopathy by arc welding. A case report.

The authors report the case of a photic maculopathy that developed in an arc welder after 5 to 10 minutes of exposure to the bright light of an electric arc, even though the young worker was wearing protective eye glasses. Pigmented foveal changes and a small central scotoma in both eyes without anomalies on fluorescein angiography characterized this maculopathy, that had a favorable course with corticosteroid therapy. Aetiopathogenetic aspects are discussed.