Hydrothermally mixed hydroxyapatite-multiwall carbon nanotubes composite coatings on biomedical alloys by electrophoretic deposition.

Hydroxyapatite (HA) coatings have been used to improve biological and mechanical fixation of metallic prosthesis. Because of extraordinary features of carbon nanotubes (CNTs), they have a lot of facilities, such as extremely strong nanoreinforcement materials for composites. HA powders were synthesized and mixed with multiwalled carbon nanotubes (MWCNTs) by a hydrothermal process. Calcium acetate (Ca (CH(3)COO)(2)) and phosphoric acid (H(3)PO(4)) were used as starting materials for synthesizing nano-HA powders. HA-MWCNTs were treated together hydrothermally at 200 °C for 2 h to synthesize nano-HA powders mixed homogeneously with MWCNTs. Cathodic deposits were obtained on Ti-based alloys using suspensions containing nano-HA and MWCNTs dispersed in n-butanol solvent. It was shown that MWCNTs interacted with HA powders during hydrothermal processing, and therefore, they can easily be dispersed within aqueous-based suspensions. It was also shown that hydrothermal surface modification of MWCNTs with functional groups was achievable, which was a significant step toward eliminating nonwetting surface behavior of MWCNTs, resulting in obtaining homogeneous dispersion of them in liquids.

Scleral tunnel for the implantation of glaucoma seton devices.

The technique described in this paper shows how to use a long scleral tunnel for the implantation of anterior tube parts of glaucoma drainage devices. It involves the creation of a scleral tunnel beginning 10 mm behind the limbus and extending to the anterior chamber. Anterior tube parts of Krupin eye valve with disk is inserted through the scleral tunnel to the anterior chamber. The disk part is secured to the episclera as used in the standard technique. We have used this technique in 6 eyes of 6 consecutive patients with refractory glaucoma. The placement of anterior tubes as part of glaucoma seton devices was done in all patients. While mean intraocular pressure (IOP) was 39.3 +/- 4.9 mm Hg (ranged from 29 to 56 mm Hg) preoperatively, it was 16.6 +/- 5.3 mm Hg (ranging from 11 to 25 mm Hg) at the end of follow up. Mean follow-up time was 7.16 +/- 1.16 months (ranging from 6 to 9 months). After surgery, conjunctival erosion or displacement of the anterior tube and dellen formation were not found in any eyes. The use of a long scleral tunnel for the implantation of anterior tube parts of glaucoma seton devices offers some advantages over standard implantation techniques.

Corneal iron ring associated with iatrogenic keratectasia after myopic laser in situ keratomileusis.

A 23-year-old woman had bilateral myopic laser in situ keratomileusis (LASIK). Two months postoperatively, she reported decreased visual acuity. Biomicroscopic examination revealed a corneal epithelial iron ring around the central keratectasia on both corneas. The appearance of the ring pattern was similar to the iron deposits of the Fleischer ring of keratoconus.

Optical coherence tomography for evaluation of anatomical changes in the cornea after laser in situ keratomileusis.

PURPOSE: To examine the use of optical coherence tomography (OCT) in evaluating anatomical changes after laser in situ keratomileusis (LASIK) and complications related to the interface and corneal flap. SETTING: Istanbul University Eye Research Center and Department of Ophthalmology, Cerrahpasa Medical School, Istanbul, Turkey. METHODS: Eleven eyes of 11 patients who had myopic LASIK were included in the study. Mean age of the 7 men and 4 women was 29.4 years +/- 6.9 (SD). Cases analyzed included uneventful LASIK (4 eyes), epithelial ingrowth (5 eyes), and flap striae (2 eyes). Corneas were examined by OCT (Humphrey Systems). RESULTS: Optical coherence tomography resolved corneal flap and residual stromal layers in all cases. The mean thickness of the corneal flap and residual stroma was 138.2 +/- 16.5 microm and 321.7 +/- 32.1 microm, respectively. Interface between the corneal flap and residual stroma was shown by OCT. Optical coherence tomography revealed that the eye with flap striae had flap displacement undetected by biomicroscopy. Epithelial ingrowth was shown as a highly reflective area. CONCLUSION: Optical coherence tomography appears to be a promising method for evaluating anatomical changes in the cornea after LASIK.

Morphologic proof of the toxicity of mitomycin C on the ciliary body in relation to different application methods.

BACKGROUND: Since postoperative hypotony has been a frequent complication of glaucomatous filtration surgery with adjunctive use of mitomycin C (MMC), the question arises of whether there may be another application method which can minimize this side effect. The purpose of this study was to establish the morphologic side effects of different application methods. METHODS: MMC 0.2 mg/ml was applied to the episclera of nine eyes of six pigmental rabbits at random via collagen shield (CS), soft contact lens (CL), or lyophilisate (20 microg; LY) for 5 min. Two eyes (controls) had a subconjunctival injection of BSS only. Another control eye was left untreated (no injection). No trabeculectomy was performed. One hour later the amounts of MMC in the conjunctiva and aqueous were analyzed by reverse-phase high-pressure liquid chromatography. Ciliary bodies were dissected from the enucleated eyes, embedded and investigated by transmission electron microscopy (TEM). Cell height of the nonpigmented ciliary epithelium was morphometrically assessed by means of computer-assisted image analysis. RESULTS: The light-microscopic analysis of the sectioned cell area revealed reduction of the cell height of the non-pigmented ciliary epithelium (NPCE) after application with soft contact lens (fourfold) and collagen shield (2.5-fold) but not with lyophilisate compared to the untreated eye. The following ultrastructural changes were seen: loss of apical microvilli (CS, CL, LY), disintegrating melanin granules within NPCE (CS), lysis of entire areas with NPCE cells (CS), myelin figures within mitochondria (LY), intracellular vacuoles (CS, CL), lysis of myelinated nerves (CS), myelin figures in mitochondria of endothelial cells (LY), and lysis of stromal fibrocytes (CS). In the control eyes (injection of BSS) none of these ultrastructural changes were detected in the cylindrical NPCE cells. The concentration of mitomycin in the aqueous humor after topical application of MMC on the episclera for 5 min were all below the detection limit (<10 ng/ml). The concentration of MMC in the conjunctiva ranged from 2.1 to 3.7 microg/g. CONCLUSION: Severe morphologic alterations were seen at the electron-microscopic level after application of MMC 0.2 mg/ml with a collagen shield and with a soft contact lens. They were mildest with lyophilisate and absent in the BSS controls. A new administration device is needed if trabeculectomy is to be performed successfully using MMC in human glaucomatous eyes.

Effect of mitomycin C on aqueous humor flow, flare and intraocular pressure in eyes with glaucoma 2 years after trabeculectomy.

BACKGROUND: The purpose of this study was to determine the intraocular pressure (IOP), aqueous humor flow, flare and ocular side effects in eyes with a history of hypotony after trabeculectomy with adjunctive mitomycin C (MMC). METHODS: Thirty-six eyes with primary or secondary open-angle glaucoma and IOP < or = 8 mmHg during the postoperative period were studied 745 +/- 315 days after surgery. MMC (0.2 or 0.5 mg/ml) was applied to the episclera with a cellular sponge. Flare was studied with the Kowa Laser Flare Meter 500. Aqueous humor flow was measured in the afternoon (Fluorotron Master II). IOP, visual fields and best corrected visual acuity were also examined. Twenty-two contralateral eyes without surgical intervention served as controls. RESULTS: The mean age of patients was 44.5 +/- 16.8 years. The mean IOP was significantly lower in the MMC group than in the control group: 9.6 +/- 6.4 mmHg vs 18.0 +/- 13.6 mmHg at 2 years (P < 0.001). Aqueous flow was significantly lower in subjects treated with MMC than in controls (P < 0.001). The flare values were significantly higher in the MMC-treated group, with a mean of 12.0 +/- 7.7 photon counts/ms, than in the control group, mean 7.9 +/- 4.6 photon counts/ms (P < 0.019). CONCLUSION: Our data suggest that MMC is a useful ocular hypotensive agent which seems to participate in a change in aqueous humor dynamics when applied topically as an aqueous solution.

Efficacy of argon laser trabeculoplasty: 3-year preliminary results of a prospective placebo-controlled study.

BACKGROUND: It was the purpose of this study to evaluate the efficacy of argon laser trabeculoplasty (ALT) in controlling intraocular pressure (IOP) and avoiding surgical intervention. We also investigated whether topically applied diclofenac sodium eye drops had an influence on the success rate of ALT compared with placebo eye drops. METHODS: The indication for ALT was progressive glaucoma uncontrolled by maximal tolerated medical therapy. Thirty-nine of 41 patients were available for follow-up after 1122 +/- 239 days. RESULTS: Twenty-one of 39 eyes failed during the first 3 years of follow-up for one or more reasons: 11 eyes required additional laser treatment and/or filtration surgery because of progressive visual field loss or unacceptably high IOP, 9 eyes failed to have a final IOP > or = 21 mmHg, and 7 eyes failed because of an increase in the number of the medications. This yields a success rate for ALT of 46% for 3-year follow-up. There was no significant difference between diclofenac sodium- and placebo-treated eyes concerning the success rate after 3 years (P > 0.05). CONCLUSION: We conclude that the use of ALT for the treatment of glaucoma is best reserved for cases in which medical avenues of treatment have been exhausted.

[The angle under anesthesia and elongation of the lateral rectus muscle in primary esotropia]. / L'angle sous anesthésie et l'élongation du droit externe dans les ésotropies primitives.

PURPOSE: In a group of 34 patients with esotropia, the anesthetic sign was studied in order to decide on the selection of the eye that should be initially operated. It is based on the examination of the variation between the angle while the patient is awake and the angle under general anesthesia applied with a definite protocole. The operated eye was always the most convergent or the less divergent one under general anesthesia. METHOD: During the operation the elongation of the medial and lateral recti belonging to the operated eye were systematically measured by Rapp-Roth myometer and Péchereau ruler. RESULTS: In 58% of cases, the examination under general anesthesia revealed an equivalent deviation of the dominated and dominant eyes form the midline. In 19% of cases convergence was obvious in the dominant eye while it existed in the dominated eyes in 23% of cases. CONCLUSION: It is concluded that a significant relationship exists between the basic angle and the variation of the angle under general anesthesia as well as between the basic angle and the elongation of the lateral rectus. Besides, this study points out the absence of relationship between the angle under general anesthesia and the elongation of the lateral rectus as well as the elongation of the two recti.

[Ocular site of pigmentation in oculodermal melanocytosis]. / Localisation oculaire de la pigmentation dans la mélanocytose oculodermique.

Sixteen patients with oculodermal melanocytosis (Nevus of Ota, congenital ocular melanocytosis) were investigated for the location and the density of the ocular pigmentation, the increase in intraocular location and the malignant transformation. In all cases, conjunctivo-scleral dispersion pattern appeared as dispersed patches without any predominant site but a diffuse involvement of the angle. This finding points out that ODM may exhibit a characteristic dispersion pattern of pigmentation which is characteristic for ODM. For 14 patients intraocular pressures were < or = 18 mmHg, and for remaining 2 patients 21 and 22 mm Hg. Glaucomatous optic disc or perimetric changes were not found in any patient. In one case, a histologically verified ciliary-choroidal melanoma at a superior-temporal site co-existed at the same location as the ODM.

The prevalence of Sjögren's syndrome in Behçet's syndrome.

OBJECTIVE: The role of autoimmune mechanisms in Behçet's syndrome (BS) is debated. Sjögren's syndrome (SS) accompanies most autoimmune diseases. Thus we investigated the prevalence of SS in BS in a formal protocol. METHODS: The study was conducted in 2 phases. During the first phase subjective symptoms of dryness were blindly assessed by questionnaires and Schirmer I and Saxon tests were done in 67 patients with BS and 100 healthy and diseased controls. During the 2nd phase 30 patients with BS and 19 with rheumatoid arthritis (RA) had salivary gland biopsies along with rose bengal dye, Schirmer I and tear breakup time tests. RESULTS: During the first phase only patients with primary SS had significantly abnormal findings. However during the 2nd phase pathologic changes in salivary gland biopsies and positive RB tests were highly significantly more prevalent among patients with RA. CONCLUSION: SS is not a feature of BS.