“Tineariasis” (or plaque-psoriasis induced by Terbinafine)

Terbinafine is an anti fungal drug used worldwide to treat dermatophytosis. Although generally is well tolerated, several cutaneous side effects have been described. One of them is the induction or exacerbation of psoriasis, especially the pustular type. We describe a case of plaque-psoriasis induced by terbinafine in a young patient. Skin biopsy was performed to confirm the diagnosis and the suspected drug was discontinued. Biopsy showed regular epidermal hyperplasia with parakeratoses and neutrophils in the corneal layer. No fungal elements were observed. Improvement was observed after discontinuation of terbinafine. We present a new case of the induction of plaque-psoriasis after the use of oral terbinafine and conclude that this drug should be used with caution in predisposed patients. Keywords: psoriasis; pustular posriasis; plaque-psoriasis; terbinafine

Spectral Transmission of the Human Corneal Layers

We have assessed the spectral transmittance of the different layers of the human cornea in the ultraviolet (UV), visible, and near-infrared (IR) spectral ranges. Seventy-four corneal sample donors were included in the study. Firstly, the corneal transmittance was measured using a spectrophotometer. Then, all samples were fixed for histopathological analysis, which allowed us to measure the thickness of each corneal layer. Finally, the absorption coefficients of the corneal layers were computed by a linear model reproducing total transmittance. The results show that corneal transmission was almost in unity at the visible and IR ranges but not at the UV range, in which the layer with higher transmission is Descemet’s membrane, whereas the stroma showed the lowest transmittance. Regarding the absorption coefficient, the most absorptive tissue was Bowman’s layer, followed by the endothelium. Variations on transmittance due to changes in the stroma, Bowman’s layer, or Descemet layer were simulated, and important transmission increases were found due to stroma and Bowman changes. To conclude, we have developed a method to measure the transmittance and thickness for each corneal layer. All corneal layers absorb UV light to a greater or lesser extent. The absorption coefficient is higher for Bowman’s layer, while the stroma is the layer with the lowest transmittance due to its thickness. Variations in stroma thickness or changes in the corneal tissue of Bowman’s layer or the endothelium layer due to some pathologies or surgeries could affect, to a greater or lesser degree, the total transmission of the cornea. Thus, obtaining accurate absorption coefficients for different layers would help us to predict and compensate these changes.

An in vivo confocal microscopy study of corneal changes in pseudoexfoliation syndrome

Purpose: To evaluate, through the in vivo confocal microscopy, the pathological changes of each corneal layer in eyes affected by pseudoexfoliation syndrome. Methods: We studied 40 eyes of 40 patients with diagnosis of unilateral senile cataract associated with pseudoexfoliation syndrome and 40 eyes of 40 control subjects with senile cataract without pseudoexfoliation syndrome. All patients underwent a complete ophthalmic examination including best corrected visual acuity, slit-lamp examination, corneal sensitivity measurement using a Cochet-Bonnet nylon thread esthesiometer, and anterior segment optical coherence tomography (Visante OCT, Carl Zeiss Meditec AG, Germany); in vivo confocal microscopy of corneal sections (endothelium, stroma, sub-basal nerve plexus, and superficial and basal epithelium) was performed with the ConfoScan 4.0 (Nidek, Japan). Results: In pseudoexfoliation syndrome group, the mean corneal sensitivity was 44.1 ± 1.3 mm and in the control group was 55.6 ± 4.7 mm. The corneas of the eyes with pseudoexfoliation syndrome were significantly less sensitive than those of control group eyes (p < 0.001). Pseudoexfoliation syndrome eyes had a lower nerve density and less nerve beadings and a higher degree of tortuosity in sub-basal plexus compared to the control group. The cell density of epithelial and endothelial layers was significantly lower in pseudoexfoliation syndrome eyes than controls. In 80% of pseudoexfoliation syndrome eyes, we found activated keratocytes and inflammatory cells in the anterior stroma. Conclusion: Our study demonstrates the morpho-structural corneal alterations in eyes affected by pseudoexfoliation syndrome, using corneal in vivo confocal microscopy as a non-invasive and high-reproducible technique to evaluate pathophysiology of each corneal layer; the sub-basal nerve plexus alterations are correlated with the lower corneal sensitivity.