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Biomedical subjects

G J Florakis

Publications and source records attributed to G J Florakis.

At least 19 recordsLinked to original sources
PubMed2000

Propionibacterium acnes as a cause of visually significant corneal ulcers.

PURPOSE: To report Propionibacterium acnes as a cause of vision-threatening infectious keratitis and to discuss culture isolation and antibiotic treatment. METHODS: Retrospective case series presentation collected from three academic medical centers. RESULTS: Six cases of P. acnes infectious keratitis are presented, all of which were associated with a compromised corneal barrier or environment. All cases were culture-positive on thioglycolate broth; none became positive before 7 days of growth. No other organisms were isolated from any culture, and the growth of P. acnes occurred in some cases despite negative gram stains. CONCLUSION: P. acnes can produce vision-debilitating keratitis when the cornea is compromised. Growth in culture should be monitored for at least 10 days to ensure isolation of this fastidious organism. P. acnes may respond to several different antibiotics that have gram-positive coverage, but it should be treated with vancomycin to enhance clearance of the organism.

Adult↗
PubMed1998

Recurrent Meesmann's corneal epithelial dystrophy after penetrating keratoplasty.

PURPOSE: To characterize the histopathology of recurrent Meesmann's corneal epithelial dystrophy after penetrating keratoplasty. METHODS: Postmortem examination by light and electron microscopy of the eyes of an 84-year-old patient with Meesmann's dystrophy who underwent a penetrating keratoplasty in the right eye at age 74 years and a lamellar keratoplasty in the left eye at age 51 years. RESULTS: In the right eye, the characteristic features of Meesmann's dystrophy were demonstrated in both the donor and recipient corneas. The pathologic findings were limited to the corneal epithelium and included increased thickness, architectural disorganization, loss of cell polarity, increased amounts of intracellular glycogen, presence of intraepithelial microcysts containing degenerated cells, and in some cells, the presence of an electron-dense fibrillogranular material associated with disrupted cytoplasmic filaments. In the left eye, the corneal findings were consistent with but not specific for Meesmann's dystrophy. These included architectural disorganization, loss of cell polarity, presence of intraepithelial microcysts, and irregular thickening of the basement membrane in the donor cornea. CONCLUSION: Meesmann's corneal epithelial dystrophy is demonstrated to recur after penetrating keratoplasty. This finding suggests that the abnormalities that lead to the disease are localized to the corneal epithelial cells and not in the stroma, as previously proposed.

Aged↗
PubMed1998

Correlation between anterior chamber IgG/albumin concentrations and laser flare photometry in eyes with endogenous uveitis.

PURPOSE: To assess the correlation between laser flare measurements and anterior chamber IgG/albumin concentrations in eyes with mild to severe inflammation. MATERIALS AND METHODS: Seventeen eyes of 17 patients with endogenous uveitis underwent diagnostic paracentesis. IgG and albumin concentrations were determined from the samples of aqueous humor. Laser flare measurements were performed 1 h prior to paracentesis. The relationship between flare measurements and IgG/albumin concentrations was studied be plotting the data on a logarithmic scale. RESULTS: The flare measurement was 97.5+/-150.0 photons ms (mean +/- SD; range 4.3-528.7). The IgG concentration was 41.0+/-51.4 mg/dl mean +/- SD; range 0.2-200). The albumin concentration was 184.6+/-196.2 mg/dl (mean +/- SD; range 4-535). When plotted on a logarithmic scale, there was a statistically significant linear relationship between the flare measurements and the anterior chamber IgG or albumin concentrations (y = 1.14x-0.64, r= 0.87, p<0.001 for IgG; y = 1.39x-0.1, r= 0.94, p<0.001 for albumin). CONCLUSION: Laser flare photometry is an accurate technique for assessing anterior chamber inflammation. Flare measurements strongly correlate with blood-aqueous barrier breakdown.

Adolescent↗
PubMed1998

Evaluation of night vision disturbances in contact lens wearers.

PURPOSE: We quantitatively recorded and evaluated night vision disturbances with physiologically dilated pupils. We compared the amount of image degradation experienced in eyes wearing spherical soft contact lenses with the amount of image degradation experienced by subjects wearing spectacles. METHODS: We prospectively evaluated 69 eyes from 35 myopic subjects with no ocular pathology. The subjects ranged in age from 22 to 35 years. We designed a test to quantitatively record image degradation with physiologically dilated pupils in scotopic conditions of dim ambient light. Previously, we have shown that this test accurately measures image degradation. We used this test to compare image degradation between new spherical soft contact lens and spectacle correction. Hyperopes and eyes with greater than 1.50 D of astigmatism were excluded. RESULTS: Adequately correcting myopic refractive error decreased recorded image degradation (P < or = 0.0001). There was no significant difference in the amount of image degradation between spectacle trial frames and new spherical soft contact lenses (P < or = 0.2885). CONCLUSIONS: Our test offers an objective method of assessing night vision disturbances in contact lens wearers. Our results suggest that image degradation, which may contribute to the sensation of glare experienced by some patients, is influenced equally by contact lens and spectacle correction.

Adult↗
PubMed1997

Scanning slit confocal microscopy of fungal keratitis.

In vivo scanning slit confocal microscopy was performed in a patient with Fusarium solani keratitis. Morphologically distinctive abundant filamentous structures were observed intrastromally. Confocal microscopy of the culture plate growing F solani from the patient's corneal scraping revealed filaments morphologically similar to the filaments observed in vivo. After 1 week of medical therapy, subsequent confocal microscopy showed an increased load of filaments, supporting the decision to perform a penetrating keratoplasty. Confocal microscopy confirmed that all of the fungus was eradicated. This aided in the decision to administer corticosteroids and quickly discontinue antifungal agents.

Adolescent↗
PubMed1996

A new scleral suction trephine for retrieval of corneoscleral donor tissue.

BACKGROUND: Removal of donor corneo-scleral shell from a cadaver, leaving the remainder of the eye in place, has become a popular technique. Manual removal can result in excessive trauma to the corneal endothelium or an uneven scleral rim. METHODS: We describe a new technique for corneal retrieval using a sceral suction trephine. RESULTS: The scleral suction trephine was cut evenly in our eyebank study. There was no additional trauma to the endothelium and the scleral rim was regular. CONCLUSION: Suction trephination of the sclera in retrieval of corneal donor tissue appears to be safe and effective.

Aged↗
PubMed1996

Night vision testing in unoperated eyes.

BACKGROUND: We previously described a simple test which evaluates image degradation in post-excimer laser (PRK) patients under scotopic conditions. After refractive surgery, corneal haze, ablation zone decentration, ablation zone/pupillary diameter disparity, and under-correction each result in a characteristic pattern on the Night Vision Recording Chart. METHODS: Using the same method, further studies evaluated night vision image degradation in 118 un-operated emmetropic, myopic, hyperopic, and astigmatic eyes and in 26 contact lens wearers. RESULTS: Scotopic image degradation increases with myopic refractive error, image displacement increases with astigmatism, and contact lens wearers have more image degradation that with spectacle correction. CONCLUSION: Our Night Vision Recording Chart offers a simple, reproducible method to characterize image degradation under scotopic conditions.

Contact Lenses↗
PubMed1996

Scleritis associated with the fibromyalgia syndrome.

We present a case of a patient with scleritis and the fibromyalgia syndrome. Scleritis and the fibromyalgia syndrome are both thought to be caused by an immunological process. This is the first report of a possible association of scleritis and the fibromyalgia syndrome. Additional cases might suggest that the fibromyalgia syndrome be added to the list of etiologies of scleritis.

Female↗
PubMed1995

Interferon treatment of Mooren's ulcers associated with hepatitis C.

PURPOSE/METHODS: The cause of Mooren's ulcer is unknown. We examined a patient with chronic hepatitis C who had a corneal ulceration that resembled Mooren's corneal ulcer. RESULTS/CONCLUSION: The corneal ulceration progressed despite appropriate medical and surgical interventions. Recombinant interferon alpha 2b finally led to resolution of the process. The resolution correlated with normalization of the patient's liver function tests. Corneal ulcerations that resemble Mooren's ulcer may be associated with hepatitis C. Recombinant interferon alpha 2b seems to induce remission in the corneal as well as the systemic condition.

Cornea↗
PubMed1995

Scanning slit confocal microscopic observation of cell morphology and movement within the normal human anterior cornea.

PURPOSE: Noninvasive in vivo observations of the anterior human cornea were performed to study cell structure and dynamics. Cellular elements were identified by their location, morphology, and pattern of movement. The hypothesis that cells in the epithelial layer of the normal cornea migrate centripetally was tested. METHODS: Using a scanning slit confocal microscope with a new 0.75-numeric aperture contact objective, individual cells of normal human corneas were observed over time, quantifying the velocity and direction of cellular movement within the basal epithelial layer. RESULTS: Basal epithelial cells, wing cells, the basal epithelial nerve plexus, and the subepithelial nerve plexus were identified readily. Centripetal motion was observed for three corneal cell types: basal epithelial cells, basal epithelial nerves, and unidentified cellular elements (possibly Langerhans cells). The unidentified cellular elements moved along the length of the basal epithelial nerves. The basal epithelial nerve plexus maintained a roughly stable topology as it slid centripetally. New nerve material appeared at the site of entry of the nerve into the epithelium. No growth cones were present at the distal termini of the growing epithelial nerves. CONCLUSION: In the midperiphery of the normal human cornea, basal epithelial cells and nerves slide centripetally, probably in concert. Unidentified cellular elements used the basal epithelial nerve plexus as a pathway for intraepithelial movement. Observations in this study suggest that neurite growth occurred by the addition of new membrane material along the length of the axon rather than at a distal growth cone.

Adult↗
PubMed1994

Do human tears absorb ultraviolet light?

We analyzed human tears by ultraviolet (UV) spectrophotometry for transmittance of UV light. Ultraviolet light was readily transmitted through human tears in the UV-A (320-400 nm) and UV-B (290-320 nm) ranges. Tears partially absorbed UV light in the UV-C (100-290 nm) range. The clinical implications of these findings include prevention of phototoxic ocular damage and effects upon excimer laser corneal photoablative techniques.

Absorption↗
PubMed1993

Clinical microscopy of the cornea utilizing optical sectioning and a high-numerical-aperture objective.

A doublet contact element was added to a long-working-distance objective to increase the numerical aperture to 0.75 and to maintain the focus during in vivo examination of the eye. Optical sectioning by use of confocal slits permits visualization of weakly scattering structures within the cornea. With photographic film and a 1/60-s exposure time to limit the effect of eye movement, an effective optical section half-thickness of approximately 20 microns was realized. Structures observed in the cornea include epithelial cells (surface, wing, and basal cells), nerve-fiber bundles in the subepithelial region, keratocytes and inflammatory cells in the stroma, and endothelial cells.

Cornea↗
PubMed1990

The pathology of posterior amorphous corneal dystrophy.

The youngest affected member of a family with a five-generation history of posterior amorphous corneal dystrophy underwent penetrating keratoplasty. The corneal button was studied by light and electron microscopy, representing the first pathologic description of this condition. Light microscopy demonstrated fracturing of the most posterior collagen layers of the stroma and focal attenuation of endothelial cells. Electron microscopy showed the collagen fibers in the most posterior stromal lamellae to be disorganized. Descemet's layer was interrupted by a band of collagen fibers resembling stroma, and there was loss of endothelial cells. These findings suggest a developmental abnormality in the formation of the posterior stroma and Descemet's membrane in posterior amorphous corneal dystrophy.

Child, Preschool↗
PubMed1988

Elevated corneal epithelial lines in Acanthamoeba keratitis.

Elevated corneal epithelial lines are another clinical sign in Acanthamoeba corneal infection. In this report, one patient wore extended wear soft contact lenses, and another wore daily wear soft contact lenses. Both patients used distilled water and salt tablets in their lens care. Histopathologic examination of these lines revealed trophozoites and cysts. In one of the patients following penetrating keratoplasty, Acanthamoeba castellani and Acanthamoeba polyphaga were cultured by impression cytology of an epithelial line, as well as from the bulbar and tarsal conjunctiva. In the other patient who did not undergo penetrating keratoplasty, these lines appeared in the cornea one month after initial symptoms.

Acanthamoeba↗
PubMedDate not supplied

Wide field scanning slit in vivo confocal microscopy of flattening-induced corneal bands and ridges.

We used a wide field scanning slit confocal microscope to examine the response of the in vivo human cornea to flattening. Flattening-induced effects consisted of (1) anterior corneal mosaic, which appeared as a meshwork of intersecting stromal and Bowman's layer bands with overlying epithelial ridges; (2) deep and middle stromal bands, which were narrower than and unrelated in position to the anterior corneal mosaic; and (3) posterior surface ridges. The posterior surface ridges projected posteriorly into the anterior chamber consisted of endothelium, Descemet's membrane, and posterior stroma, and were unrelated in position to posterior stromal bands. Confocal microscopy is a promising modality in the examination of the cornea and its response to mechanical stress.

Cornea↗
PubMedDate not supplied

Management of conjunctival cicatrizing diseases and severe ocular surface dysfunction.

Physical or chemical injuries, infections, immunologic oculocutaneous disorders, drugs, and various systemic disorders may cause scarring of the conjunctiva and disturbances of the ocular surface. Trichiasis, lid margin malposition, and dry eye may result in persistent ocular irritation. The cornea may be primarily or secondarily involved. If severe, disturbances of the ocular surface may lead to significant visual impairment. Thorough evaluation of patients and of the underlying disease process is required for optimal management. Treatment may be challenging and should be comprehensive, combining medical measures and surgical correction of structural changes. Suppression of exogenous irritants, treatment of dry eye, antiinflammatory therapy, and immunosuppressants are paramount to control the underlying disease and allow optimal surgical results. Surgical correction of trichiasis and lid margin malposition, conjunctival grafting, mucous membrane transplantation, limbal stem cell transplantation, amniotic membrane transplantation, and penetrating keratoplasty help reestablish a physiologic ocular surface. Severe cases may require keratoprosthetics for visual rehabilitation. Corneal ulceration or perforation requires prompt attention to maintain ocular integrity. Special measures should be considered for patients who require cataract or glaucoma surgery.

Cicatrix↗