Biomedical subjects

Mario A Di Pascuale

Publications and source records attributed to Mario A Di Pascuale.

12 recordsLinked to original sources

PubMed2005

Lipid tear deficiency in persistent dry eye after laser in situ keratomileusis and treatment results of new eye-warming device.

PURPOSE: To determine whether lipid tear deficiency is a significant pathogenic factor in persistent dry eyes after laser in situ keratomileusis (LASIK). SETTING: Ocular Surface Center, Miami, Florida, USA. METHODS: Thirty-four eyes of 17 patients (mean 46.35 years +/- 11 [SD]) complaining of persistent dryness more than 12 months after LASIK were prospectively studied by symptom scoring and kinetic analysis of tear interference image, tear breakup time, and fluorescein clearance test. Once patients had been clear of inflammation and treated for aqueous tear deficiency, lipid tear deficiency was further confirmed and treated with Eyefeel (Kao, Inc.), an eye-warming device, 4 times daily for 4 weeks. RESULTS: Sixteen patients were asymptomatic before LASIK but dryness persisted for 41 +/- 19.3 months. Delayed tear clearance was observed in 15 patients (88.2%) and floppy lids in 12 patients (70.5%). Aqueous tear deficiency was reconfirmed in 16 eyes (53.3%). After Eyefeel treatment, there was a subjective improvement of ocular surface diseases index from 60.6 +/- 10.6 to 25.8 +/- 18.5 (P = .0007). Tear breakup time was improved from 2.4 +/- 3.9 seconds to 7.9 +/- 3.6 seconds (P = .004). There was a tear interference pattern change from a vertical lipid tear deficiency to a horizontal normal in 7 eyes. There was a mean lipid spread time improvement from 1.3 +/- 0.4 sec to 0.8 +/- 0.4 sec (P = .001), and there was a mean lipid thickness improvement from 63.5 +/- 23 nm to 79.5 +/- 27 nm (P = .04). CONCLUSION: Persistent nature of dry eye after LASIK is attributed to in part to delayed tear clearance, undercorrected aqueous tear deficiency, and nonrecognized lipid tear deficiency.

Adult↗

PubMed2005

Correlation of corneal complications with eyelid cicatricial pathologies in patients with Stevens-Johnson syndrome and toxic epidermal necrolysis syndrome.

PURPOSE: To look at the correlation between many factors (time of hospitalization, floppy eyelid syndrome, trichiasis, open lacrimal puncta, symblepharon, and aqueous tear deficiency) and corneal complications in Stevens-Johnson syndrome (SJS). DESIGN: Observational cases series. PATIENTS: Clinical data were retrospectively reviewed from 38 patients (32.7+/-20.1 years old) with SJS (n = 11) and with toxic epidermal necrolysis (TENS) (n = 27) from January 2002 to August 2004. One case report with SJS was included to verify the presence of tarsal/lid margin ulceration at the acute stage. METHODS: The medical history was retrieved regarding presumed causative medications used within 15 days and the duration of hospitalization. Data of the latest photographic documentation and eye examination were compared and correlated in a masked fashion. MAIN OUTCOME MEASURES: Floppy eyelid, trichiasis, lid margin keratinization, meibomian gland orifice metaplasia, symblepharon, tarsal scar, and corneal complications. RESULTS: Acute SJS/TENS was characterized by tarsal conjunctival ulceration. Keratinization of the eyelid margin with variable degrees of meibomian gland dysfunction was observed in all cases. Floppy eyelid, trichiasis, partially or totally opened lacrimal punctum, symblepharon, and aqueous tear deficiency were not significantly correlated with corneal complications. In contrast, there was a strong correlation between the severity of eyelid margin and tarsal pathology and the extent of corneal complications (Spearman r, 0.54; P = 0.0005). A multivariable regression analysis also showed that the extent of eyelid and tarsal pathology had a significant effect on corneal complications (coefficient, 0.84; P = 0.006). CONCLUSIONS: Patients with acute SJS/TENS are characterized by severe inflammation and ulceration of the tarsal conjunctiva and lid margins. If left unattended, lid margin keratinization and tarsal scar, together with lipid tear deficiency, contribute to corneal complications because of blink-related microtrauma. Attempts to suppress inflammation and scarring by amniotic membrane transplantation at the acute stage and to prevent microtrauma at the chronic stage are vital to avoid sight-threatening complications.

Adolescent↗

PubMed2005

Intraoperative mitomycin C and amniotic membrane transplantation for fornix reconstruction in severe cicatricial ocular surface diseases.

PURPOSE: To investigate whether intraoperative application of mitomycin C may enhance the success of amniotic membrane transplantation in symblepharon lysis and fornix reconstruction in severe cicatricial ocular surface diseases. DESIGN: Noncomparative interventional case series. PARTICIPANTS: Sixteen patients (8 female, 8 male; 18 eyes) with a mean age of 41+/-23.4 years (range, 3-79) and suffering from severe chemical/thermal burns (7 eyes), multiple recurrent pterygia and pseudopterygia (5 eyes), Stevens-Johnson syndrome (4 eyes), and ocular cicatricial pemphigoid (2 eyes) were consecutively enrolled. All except for 2 eyes had had prior surgical attempts of surgical reconstruction, including 6 eyes with a mucous membrane graft (MMG), but still presented with symblepharon and persistent ocular surface inflammation. INTERVENTION: After excision of subconjunctival fibrovascular tissues, 0.04% mitomycin C was applied for 5 minutes in the deep fornix before amniotic membrane transplantation. MAIN OUTCOME MEASURES: Deeper fornix, noninflamed ocular surface, and full motility. RESULTS: The mean epithelial healing time was 4.2+/-1.9 weeks. During the follow-up of 14.16+/-5.2 months, all eyes showed a marked reduction of conjunctival inflammation, a deep fornix, and a continuous tear meniscus. Of 12 eyes with motility restriction, 2 eyes with multiple recurrent pterygia and 1 eye with severe thermal burn showed recurrence of partial motility restriction 2 months after surgery. The vision of 9 eyes was successfully restored by an additional keratolimbal allograft with subsequent penetrating keratoplasty (6 eyes). CONCLUSION: Intraoperative application of mitomycin C is an effective means to reduce chronic and deep-seated conjunctival inflammation, and helps amniotic membrane restore a deep fornix after symblepharon lysis, even in eyes that had a failed MMG. Restoration of deep fornix and tear meniscus is an important prerequisite to achieve successful reconstruction by subsequent limbal stem cell transplantation.

Adolescent↗

PubMed2005

Detection of corneal epithelial defect through amniotic membrane patch by fluorescein.

PURPOSE: To demonstrate the usefulness of fluorescein dye to detect a corneal epithelial defect through an amniotic membrane patch in 4 cases. PATIENTS AND METHOD: Two patients with painful bullous keratopathy, 1 patient with total limbal deficiency, and 1 patient with acute chemical burn underwent surgeries in conjunction with amniotic membrane as patch. Postoperatively, slit-lamp biomicroscopic examination with and without fluorescein staining was performed. RESULTS: The status of epithelialization, ie, corneal epithelial defect on either denuded corneal stroma or amniotic membrane graft, was indiscernible by slit-lamp biomicroscopy through the amniotic membrane patch. Nevertheless, it could be detected by fluorescein staining, especially after saline rinse, in all 4 cases. CONCLUSIONS: Fluorescein staining permits clinicians to avoid prematurely removing the amniotic membrane patch during the treatment of a persistent corneal epithelial defect.

Administration, Topical↗

PubMed2005

Tear film dynamics in floppy eyelid syndrome.

PURPOSE: Floppy eyelid syndrome (FES) presents nonspecific ocular surface irritation. The hypothesis for the current study was that one contributing factor is the abnormality in tear film dynamics. METHODS: Sixteen patients with FES were consecutively examined. Tear film dynamics were evaluated by kinetic tear interference images, infrared thermometry, water evaporation rate, tear break-up time, and fluorescein clearance test. Data showing evaporation rate and thermometry were compared with those of 10 normal subjects. RESULTS: There was a high correlation between the eye with the worse symptoms and the eyes with the more severe floppy lids (P < 0.01) and with ocular surface evaporation rate (P = 0.02). Except for one patient, all others showed abnormal tear film, with an average tear break-up time of 2.9 +/- 3.7 seconds. Kinetic analysis of tear interference images revealed that lipid spread in a vertical or mixed pattern in 18 eyes (75%) with a delayed spread time (P = 0.0007), indicating that most of the patients had lipid tear deficiency. The ocular skin temperature and water evaporation rate were higher in the FES group (P = 0.0003 and 0.026, respectively). Nearly all patients with FES showed eyelid hyperpigmentation. The ocular surface evaporation rate in the FES group was also higher than that of the normal subjects (P < 0.0001). Multiple regression analysis showed that a vertical pattern of lipid spread had a significant influence on ocular surface evaporation rate (P = 0.003). CONCLUSIONS: Tear film abnormality is prevalent in patients with FES and is characterized by lipid tear deficiency, leading to rapid tear evaporation. The FES lid skin is also characterized by high temperature, high water evaporation rate, and hyperpigmentation. Studies directed to investigating the linkage of lid changes and meibomian gland dysfunction may shed new lights on the pathogenesis of FES.

Adult↗

PubMed2005

The heterogeneous murine corneal stromal cell populations in vitro.

PURPOSE: To demonstrate that the murine corneal stroma is inhabited by heterogeneous cell populations that include cells expressing nestin. METHODS: Collagenase-isolated corneal stroma cells obtained from newborn and adult mice (2nd and 12th postnatal weeks, respectively), were seeded at low (5 cells/mm2), intermediate (50 cells/mm2), and high (500 cells/mm2) densities in DMEM/F12 containing insulin, transferrin, selenium, and 1% nonessential amino acids. Corneal stroma cells cultured at 500 cells/mm2 were treated with 10 ng/mL human recombinant transforming growth factor (TGF)-beta1 for 5 days. Cell morphology and expression of alpha-smooth muscle actin, choline acetyltransferase, CD45, glial fibrillary acidic protein (GFAP), keratocan, nestin, neurofilaments, protein gene product 9.5, tyrosine hydroxylase, and vimentin were examined. RESULTS: Phase-contrast microscopy demonstrated that freshly isolated corneal stromal cells are heterogeneous in morphology and include dendritic, stellate, neuronal, and small polyhedral cells. Immunostaining of primary cultures of 2- and 12-week-old mice, 24 hours after seeding at the intermediate density, showed that 100% of cells expressed vimentin and 97.7% +/- 2.7% expressed keratocan. alpha-Smooth muscle actin was expressed by 0.2% +/- 0.05% of cells in the 2-week-old group and 0.1% +/- 0.07% in 12-week-old group. Neurofilament was expressed by 0.5% +/- 0.03% and 0.7% +/- 0.03% of cells in the 2- and 12-week-old groups, respectively. No cell expressed GFAP or nestin. After 5 days in culture, cells seeded at high density aggregated as clusters that were immunoreactive to nestin in both groups. Cell clusters and migrating cells reacted to pgp 9.5, and migrating cells, but not the cell clusters, reacted to tyrosine hydroxylase. Cell cluster formation and nestin expression were abolished by culturing in the presence of TGF-beta1. CONCLUSIONS: Normal murine corneal stroma contains heterogeneous cell populations including cells with the potential to form clusters and express the progenitor marker nestin. This potential is disrupted by the addition of TGF-beta1 to the culture medium.

Actins↗

PubMed2005

High prevalence of Demodex in eyelashes with cylindrical dandruff.

PURPOSE: To determine the prevalence of Demodex in eyelashes with cylindrical dandruff (CD). METHODS: A modified sampling and counting method was applied to 55 clinical cases. Patients were divided in to group A (n = 20) with diffuse CD, group B (n = 12) with sporadic CD, and group C (n = 23) with clean lashes or greasy scales, of which the latter was divided into subgroup C1 (n = 15) without lid hygiene and subgroup C2 (n = 8) using daily lid hygiene for the past year. Each patient underwent a routine complete eye examination and modified counts of Demodex. RESULTS: Demodex was found in all group A and B patients (n = 32) with CD, which was significantly higher than the 22% of group C patients (n = 23) without CD (P < 0.001). The Demodex counts were 4.1 +/- 1.0 and 2.0 +/- 1.2 per epilated lash with retained CD, significantly higher than the 0.2 +/- 0.5 and 0.2 +/- 0.4 per lash without retained CD in groups A and B, respectively (each P < 0.001) and than the 0.01 +/- 0.09 and 0.12 +/- 0.41 per lash in subgroups C1 and C2, respectively (each P < 0.001). Demodex was still found in CD fragments left on the lid skin after epilation. Five Demodex brevis mites were found among the 422 Demodex specimens. CONCLUSIONS: The modified sampling and counting method showed that the prior controversy regarding Demodex has resulted from miscounting and confirmed that lashes with CD are pathognomonic for ocular Demodex infestation. Lid hygiene with shampoo reduces Demodex counts but does not eradicate the mites.

Adult↗

PubMed2004

Sequential changes of lipid tear film after the instillation of a single drop of a new emulsion eye drop in dry eye patients.

PURPOSE: The lipid tear film stabilizes the tears by lowering the surface tension and preventing aqueous tear evaporation and may be analyzed by kinetic analysis of the tear interference images. This study investigated changes in the lipid film after application of a new emulsion-based eye drop of Refresh Endura (Allergan, Irvine, CA) in normal subjects and patients with dry eyes. DESIGN: Comparative, nonrandomized interventional study. PARTICIPANTS: Five normal subjects and 10 aqueous tear deficiency (ATD) patients with or without lipid tear deficiency were enrolled prospectively. METHODS: A complete eye examination was performed, including symptom score, tear break-up time, dye staining, and fluorescein clearance test. One eye received a single dose of emulsion eye drop (EED), whereas the other eye received nonpreserved saline as a control. Kinetic analysis of tear interference images taken by DR-1 (Kowa, Japan) was performed before and at various times after instillation of the drops. MAIN OUTCOME MEASURES: Symptoms, pattern, thickness, and spread time of the tear film. RESULTS: Compared with the control, all eyes receiving EED showed rapid restructuring of the preexisting lipid film. In normal persons, restructuring resulted in a thick lipid band across the cornea and a significant increase of the lipid film thickness. For ATD patients, EED application resulted in either a scant, irregular tear film, which became covered by the lipid film, or a modified lipid film changed without forming a band or irregularities. Emulsion eye drops tended to be more comfortable in patients with more severe ATD. Kinetic analysis showed that the mean spread time improved for all patients after EED when compared with baseline or with controls (P<0.05). CONCLUSIONS: Emulsion eye drop produces significant changes in the tear film of normal and dry eye patients. Further investigation with a prolonged period of treatment is warranted to establish whether EED may help improve the spread and thickness of the lipid tear film in moderate and severe dry eyes.

Adult↗

PubMed2004

How does amniotic membrane work?

Transplantation of amniotic membrane as a temporary or permanent graft promotes epithelial wound healing and exerts potent anti-inflammatory and anti-scarring effects on the ocular surface. These actions depend on the killing of allogeneic amniotic cells and preservation of the cytokine-containing matrix during the preparation of the amniotic membrane. This review describes how these actions inherently operate in utero and how amniotic membrane transplantation aims to recreate such a fetal environment to exert these actions by insulating the surgical site from the host environment. These actions also render the amniotic membrane a unique niche capable of expanding both epithelial and mesenchymal progenitor cells ex vivo, while maintaining their normal cell phenotypes. As a result, the amniotic membrane becomes an ideal substrate for engineering different types of ocular surface tissues for transplantation. Further studies investigating the exact molecular mechanism by which the amniotic membrane works will undoubtedly unravel additional applications in reconstruction and engineering of both ocular and nonocular tissues in the burgeoning field of regenerative medicine.

Journal Article↗

PubMed2004

A case of conjunctiva-cornea intraepithelial neoplasia successfully treated with topical mitomycin C and interferon alfa-2b in cycles.

PURPOSE: To report a case of conjunctiva-cornea intraepithelial neoplasia (CCIN) treated with topical mitomycin C (MMC) and interferon alfa-2b in cycles. METHODS: A 52-year-old woman referred for limbal stem cell deficiency and epithelial defect was found instead to have CCIN. The diagnosis was confirmed by impression cytology and treated in cycles with topical 0.02% MMC for 14 days in the first cycle, 12 days in the second cycle, and 3 days in the third cycle followed by topical interferon alfa-2b 1 x 106 U/mL for 11 days. RESULT: Topical MMC for 2.5 cycles resulted in 95% reduction of CCIN and improvement of 2 lines of vision. Because of intolerance to MMC, she was switched to topical interferon alfa-2b for 11 days, resulting in total resolution of CCIN, which lasted for at least 10 months. CONCLUSIONS: After differentiation from a persistent corneal epithelial defect and limbal stem cell deficiency by dye staining and impression cytology, the patient in this case of CCIN was successfully treated with topical MMC and interferon alfa-2b in cycles.

Administration, Topical↗

PubMed2004

Characterization of corneal pannus removed from patients with total limbal stem cell deficiency.

PURPOSE: To determine the epithelial lineage of origin in corneal pannus tissue surgically removed from patients with total limbal stem cell (SC) deficiency. METHODS: The lineage of origin of the entire conjunctivalized pannus removed from eight corneas with a diagnosis of total limbal SC deficiency was characterized by anti-keratin (K)-3 and anti-K19 monoclonal antibodies. The protein and mRNA of epithelial outgrowth from segments of five such pannus specimens were analyzed by Western blot and reverse transcription-polymerase chain reaction, respectively. RESULTS: Cross sections of all eight specimens showed a stratified epithelium with goblet cells expressing mucin (MUC)-5AC, and a stroma showing blood vessels and inflammatory cell infiltrates. Immunostaining showed full-thickness expression of K19 in the entire pannus of all eight specimens. Expression of K3 was negative in seven patients, but was sporadically positive in a patient with Stevens-Johnson syndrome. In culture, all five pannus specimens generated a compact, small epithelial cell outgrowth, and except for one, reached confluence in 2 to 3 weeks. The K3/K12 pair was expressed by extracts of cell outgrowth from the control limbal epithelial explant, but not in all five pannus specimens. A 60-kDa band of DeltaNp63 was expressed in the control specimen and in all five pannus specimens. Cell outgrowth expressed K3 transcript in three, but none showed K12 transcript. CONCLUSIONS: The resultant epithelial phenotype of the pannus tissue was not corneal, as evidenced by the negative staining to cornea-specific K12 mRNA and protein, but was conjunctival, as evidenced by the presence of goblet cells, the weak expression of K3, and the strong expression of K19. The abundant expression of DeltaNp63 in such conjunctiva-derived epithelium in eyes with total limbal SC deficiency raises doubts as to its validity as a limbal SC marker.

Adult↗

PubMed2003

Human keratocytes cultured on amniotic membrane stroma preserve morphology and express keratocan.

PURPOSE: To develop a new method of expanding human corneal keratocytes in serum while maintaining their characteristic morphology and keratocan expression. METHODS: Human keratocytes were isolated from central corneal buttons by digestion in 1 mg/mL of collagenase A in DMEM and seeded on plastic or the stromal matrix of human amniotic membrane (AM) in DMEM with different concentrations of FBS. On confluence, cells on AM were continuously subcultured for six passages on AM or plastic. In parallel, cells cultured on plastic at passages 3 and 11 were reseeded on AM. Cellular morphology and cell-cell networks were assessed by phase-contrast microscopy and a cell viability assay, respectively. Expression of keratocan was determined by RT-PCR and Western blot analysis. RESULTS: Trephined stroma yielded 91,600 +/- 26,300 cells (ranging from 67,000 to 128,000 cells per corneal button). Twenty-four hours after seeding, cells appeared dendritic on AM, even in 10% FBS but fibroblastic on plastic. Such a difference in morphology correlated with expression of keratocan assessed by RT-PCR and Western blot, which was high and continued at least to passage 6 on AM, even in 10% FBS, but was rapidly lost each time when cells on AM were passaged on plastic. Fibroblasts continuously cultured on plastic to passages 3 and 11 did not reverse their morphology or synthesize keratocan when reseeded on plastic in 1% FBS or on AM. CONCLUSIONS: Human keratocytes maintain their characteristic morphology and keratocan expression when subcultured on AM stromal matrix even in the presence of high serum concentrations. This method can be used to engineer a new corneal stroma.

Amnion↗