PubMed Health⌕ Search

Biomedical subjects

D Maitchouk

Publications and source records attributed to D Maitchouk.

4 recordsLinked to original sources
PubMed1999

Confocal microscopy in posterior polymorphous corneal dystrophy.

PURPOSE: To report the distinguishing characteristics of posterior polymorphous corneal dystrophy (PPMD) using confocal microscopy. MATERIAL AND METHODS: Two consecutive patients with PPMD were prospectively examined using a white-light tandem scanning confocal microscope with a 24x/0.60 contact objective. RESULTS: At the level of Descement's membrane, roundish hyporeflective images were found in 1 patient. In the other patient, hyporeflective bands were detected. In both patients, patchy hyperreflective areas were identified. CONCLUSION: Confocal microscopy may allow diagnosis of PPMD by demonstrating the alterations in Descement's membrane. This technique is especially valuable in cases of endothelial decompensation, where slit-lamp and specular microscopy may fail to demonstrate changes in Descement's membrane.

Aged↗
PubMed1998

Characterization of fibrous retrocorneal membrane by confocal microscopy.

PURPOSE: To study the appearance of a fibrous retrocorneal membrane as seen by confocal microscopy. METHODS: A 67-year-old white woman with a history of multiple ocular surgeries, including repeated penetrating keratoplasties for aphakic bullous keratopathy, developed a retrocorneal membrane in the right eye. The membrane was first noticed 3 years after the last corneal transplant and remained stable subsequently. The patient was examined by in vivo white light tandem-scanning confocal microscopy. RESULTS: At the level of the retrocorneal membrane, confocal microscopy disclosed the presence of a hyperreflective fibrous-appearing layer. Normal endothelial cells could not be found. Anterior to the hyperreflective layer, activated keratocytes were identified. CONCLUSION: Confocal microscopy may allow noninvasive diagnosis of fibrous retrocorneal membrane. Additionally, our data suggest that the posterior keratocytes might play a role in the production and deposition of fibrous tissue.

Aged↗
PubMed1997

Detection of substance P in human tears by laser desorption mass spectrometry and immunoassay.

PURPOSE: To determine whether substance P is present in human tears. METHODS: Tear samples (1-2 microliters) were collected from one eye of each of 12 subjects. Two of the eyes had dry eye syndrome, two wore contact lenses and had dry eye syndrome, and eight were normal. Five of the eight normal eyes were scheduled to undergo excimer laser refractive surgery, and tears were collected from these eyes before and after surgery. Tear samples were analyzed by laser desorption mass spectrometry. Pooled samples from one individual were subjected to enzyme-linked immunoabsorbent assay. RESULTS: Laser desorption mass spectra of the 18 tear samples displayed well defined peaks with mass to charge (m/z) ratios ranging from 1343.7 to 1355.9 and/or 1356.9 to 1364.7, corresponding to an average m/z of 1349.8 +/- 1.13 for protonated substance P and 1361.2 +/- 0.54 for oxidized substance P obtained from 14 mass spectra of standards formulated with substance P concentrations ranging from 10(-4) M to 10(-12) M. As confirmation, an enzyme-linked immunoabsorbent assay performed twice on pooled tears from one eye detected substance P in both replicates at a concentration of 125 pg/ml (9.26 x 10(-11) M). CONCLUSIONS: These findings demonstrate that substance P is a component of tears obtained from normal eyes of men and women ranging in age from 26 to 60 years, from eyes fitted with contact lenses, from eyes with dry eye syndrome, and from eyes 1 and 2 days after excimer laser refractive surgery. Whether the concentration of substance P in tears varies with sex, age, or eye condition, the source of substance P in tears, and its role in tears remains to be discovered.

Adult↗