Savoldelli M

Damage to the Corneal Endothelium by Minus Power Anterior Chamber Intraocular Lenses

We present 16 phakic myopic eyes (from -10.00 to -25.00 diopters) corrected by minus power intraocular lenses implanted in the anterior chamber whose corneal endothelium was observed by specular microscopy during a postoperative period from 6 to 18 months. Significant morphologic endothelial changes were noted in three eyes along the border of the lens optic. Around dark zones, which appeared acellular, endothelial cells were enlarged, deformed, and separated. These findings may be produced by intermittent contact between the endothelium and lens. Corneal indentation during specular microscopy occasionally caused a curvilinear reflection which corresponded to the optic border. In three eyes, dark areas without cellular abnormality were observed near the curved edge of the lens. These findings probably resulted from the disturbance of the specular reflection on part of the endothelium due to this edge.

A viscous bioerodible poly(ortho ester) as a new biomaterial for intraocular application

The biocompatibility of a viscous, hydrophobic, bioerodible poly(ortho ester) (POE) intended for intraocular application was investigated. POE was evaluated as a blank carrier and as containing modulators of degradation. Each formulation was injected intracamerally and intravitreally in rabbit eyes, and clinical and histological examinations were performed postoperatively for 2 weeks. In the case of intracameral injections, polymer biocompatibility appeared to depend on the amount injected in the anterior chamber. When 50 microL was administered, the polymer degraded within 2 weeks, and clinical observations showed good biocompatibility of POE with no toxicity to the ocular tissues or increase in intraocular pressure. The injection of a larger volume, 100 microL, of POE, appeared inappropriate because of direct contact of polymeric material with the corneal endothelium, and triggered reversible edema and inflammation in the anterior chamber of the eye that regressed after a few days. After intravitreal administration, POE was well tolerated and no inflammatory reaction developed during the observation period. The polymer degraded slowly, appearing as a round whitish bubble in the vitreous cavity. The presence of modulators of degradation both improved POE biocompatibility and prolonged polymer lifetime in the eye. POE appears to be a promising biomaterial for clinical intraocular application.

Morphologic and electroretinographic phenotype of SR-BI knockout mice after a long-term atherogenic diet.

PURPOSE To evaluate functional and ultrastructural changes in the retina of scavenger receptor B1 (SR-BI) knockout (KO) mice consuming a high fat cholate (HFC) diet. METHODS Three-month-old male KO and wild-type (WT) mice were fed an HFC diet for 30 weeks. After diet supplementation, plasma cholesterol levels and electroretinograms were analyzed. Neutral lipids were detected with oil red O, and immunohistochemistry was performed on cryostat ocular tissue sections. The retina, Bruchs membrane (BM), retinal pigment epithelium (RPE), and choriocapillaris (CC) were analyzed by transmission electron microscopy. RESULTS Using the WT for reference, ultrastructural changes were recorded in HFC-fed SR-BI KO mice, including lipid inclusions, a patchy disorganization of the photoreceptor outer segment (POS) and the outer nuclear layer (ONL), and BM thickening with sparse sub-RPE deposits. Within the CC, there was abnormal disorganization of collagen fibers localized in ectopic sites with sparse and large vacuolization associated with infiltration of macrophages in the subretinal space, reflecting local inflammation. These lesions were associated with electroretinographic abnormalities, particularly increasing implicit time in a- and b-wave scotopic responses. Abnormal vascular endothelial growth factor (VEGF) staining was detected in the outer nuclear layer. CONCLUSIONS HFC-fed SR-BI KO mice thus presented sub-RPE lipid-rich deposits and functional and morphologic alterations similar to some features observed in dry AMD. The findings lend further support to the hypothesis that atherosclerosis causes retinal and subretinal damage that increases susceptibility to some forms of AMD.

Treatment of ocular cicatricial pemphigoid with sulfasalazine

PURPOSE To report on three patients with biopsy-proven ocular cicatricial pemphigoid successfully treated with sulphasalazine. METHODS Three case reports. RESULTS A 71-year-old man, treated with dapsone for ocular cicatricial pemphigoid stopped his treatment because of an allergy to this drug. Oral sulphasalazine, 2.5 grams daily was successfully used as an alternative treatment (3 month follow-up). Two patients, aged 71 and 84 year old, were treated with dapsone for ocular cicatricial pemphigoid. Both patients stopped their treatment because of drug induced hemolytic anemia. They then received oral sulphasalazine, 4 grams daily. The disease was successfully controlled. In the first patient, sulphasalazine was discontinued after 13 months; and in the second patient no relapse was seen after a 16 month follow-up period. No adverse side effect of sulphasalazine occurred. CONCLUSION Sulphasalazine, that has already been proven to be effective for Crohns disease, also can be used in ocular cicatricial pemphigoid. However, further studies including a larger series of patients along with a longer follow-up are necessary to confirm the efficacy of sulphasalazine in this disease.

Keratoconus and normal cornea: a comparative study of the collagenous fibers of the corneal stroma by image analysis.

Using an automatic image analysis technique, we studied the characteristics of the collagenous fibers of the corneal stroma of keratoconus at different stages of development. The clear portions of keratoconus specimens were studied at three different levels: anterior, middle, and posterior. The parameters obtained were compared with those of a normal adult cornea with the purpose of determining which ultrastructural alterations were caused by the appearance and progression of keratoconus.

Drug-induced Cicatricial Pemphigoid Affecting the Conjunctiva

Cicatricial pemphigoid (CP) is a chronic inflammatory disease which can affect the conjunctiva. It is a slowly progressive disorder of unknown but presumed autoimmune etiology. Pseudopemphigoid, or CP associated with ocular drug administration, has also been described. These cases, which appear clinically indistinguishable from unilateral idiopathic CP affecting the conjunctiva, have been related to the use of echothiophate iodide, pilocarpine, idoxuridine, and epinephrine. We report the histopathologic and ultrastructural characteristics of 22 biopsies from ten patients with iatrogenic CP following the use of various ocular drugs. All patients presented with clinically obvious, active CP affecting the conjunctiva. Light microscopy and electron microscopy revealed findings identical to those previously reported for idiopathic CP of the conjunctiva: squamous metaplasia, increased numbers of desmosomes, basal lamina modifications suggestive of damage and attempted repair, subepithelial inflammatory cell infiltration, and diminished intravascular space within the stroma. These patients responded to immunosuppressive therapy. The authors wonder if it is possible that these patients were destined to develop CP, but that with topical ocular drug use, a more rapid emergence of the chronic cicatrizing feature of CP developed.

Acute corneal edema in pellucid marginal degeneration or acute marginal keratoconus.

This article reports a case of bilateral corneal pellucid marginal degeneration. The right cornea had an acute hydrops. Both eyes underwent penetrating keratoplasty. A histopathological study of the corneal specimens was performed by light and electron microscopy. The histological changes observed on the right cornea showed breaks on Bowmans layer, edema and disorganization of the stromal collagen, and break of Descemets membrane. The ultrastructural changes were similar to those observed in acute keratoconus, leading to the belief that these two corneal diseases are closely related.

Histologic and ultrastructural characterization of corneal femtosecond laser trephination.

Purpose: The purpose of this study was to evaluate the quality of femtosecond laser corneal trephination in eye bank eyes by histologic and ultrastructural investigation. Methods: We performed Z-shaped, tophat-shaped, and mushroom-shaped trephinations of swelled corneas from eye bank eyes using an Intralase FS60 system. The corneoscleral discs were fixed immediately after the laser procedure without removing the buttons. Thin and ultrathin tissue sections were examined by light and transmission electron microscopy. Results: Optical micrographs of the corneal tissue revealed that the femtosecond laser was efficient in producing Z-shaped, tophat-shaped, and mushroom-shaped dissections with reproducible high cut regularity. Investigations by transmission electron microscopy demonstrated that cut edges were of good quality devoid of thermal or mechanical damage of the adjacent tissues. However, cellular and collagenous nanometric debris was created by the laser. In the anterior stroma, they formed a layer of several microns in thickness residing on the terminated disrupted collagen fibers, whereas in the posterior stroma, they formed a thinner pseudomembrane running along the edges of the incision. Conclusions: Corneal trephination performed by the femtosecond laser preserves the ultrastructure of the disrupted collagen fibers. In edematous corneas, a layer of cellular and collagenic debris thicker in the anterior stroma and thinner in the posterior stroma runs along the edges of the incision obtained at a constant laser energy density.

The Effect of Gentamicin on the Corneal Endothelium

Gentamicin sulfate with preservatives was injected into the anterior chamber of a rabbit eye to evaluate its effect on the corneal endothelium. Endothelial toxicity was evaluated by contact specular microscopy and transmission electron microscopy 48 h after injection. The results suggest that doses ranging from 100 to 400 micrograms of gentamicin are not toxic to the corneal endothelium. Endothelial toxicity occurred when 1,000 micrograms of gentamicin was injected.

Microcomputer software applied to corneal stromal biometry.

Here we report a new method for image analysis of the corneal stroma. To obtain the biometric characteristics of a given area, we perform three different treatments of the same image. These automated predictions closely match each parameter (length, surface area, etc.), as measured manually by a “blind investigator.” Furthermore, to obtain quantifiable, average values, we have increased the number of successive image measurements, which has led to the development of a series of programs designed to optimize automated data handling. Finally, the acquired, calculated parameters are summarized in the form of intermediate tables for each series of images, and as a final summary table incorporating t-test values and permitting comparison between two stromas (e.g., normal and pathological). Multivariate analysis and an ascending hierarchical classification demonstrate the main trends in differences of pathological vs. normal stroma.