Biomedical subjects

Ayfer Kanpolat

Publications and source records attributed to Ayfer Kanpolat.

11 recordsLinked to original sources

PubMed2006

Superoxide dismutase activity in the lens capsule of patients with pseudoexfoliation syndrome and cataract.

PURPOSE: To evaluate the activity of the antioxidative enzyme superoxide dismutase (SOD) in the anterior lens capsule of patients with cataract complicating pseudoexfoliation syndrome (PEX) in an attempt to determine the role of the oxidative mechanisms in the etiopathogenesis of this disorder. SETTING: Departments of Ophthalmology and Biochemistry, Ankara University School of Medicine, Ankara, Turkey. METHODS: At the beginning of phacoemulsification surgery, the anterior lens capsules in 21 eyes with PEX and cataract (group A) and those in 24 eyes with cataract alone (group B) were collected with continuous curvilinear capsulorhexis and were frozen at -20 degrees C. At the time of analysis, the specimens were thawed and centrifuged and the supernatants of the homogenate obtained from the samples were analyzed for the activity of the enzyme SOD. RESULTS: The mean age of patients was 74.8 years +/- 5.5 (SD) in group A and 71.7 +/- 5.6 years in group B. The specific activity of SOD was 17.6 +/- 10.8 IU/mg and 4.36 +/- 1.80 IU/mL in group A and 9.9 +/- 12.9 IU/mg and 2.71 +/- 2.61 IU/mL in group B. Superoxide dismutase activity was significantly higher in group A patients than in group B patients (P = .022 and P = .011, respectively). CONCLUSIONS: The increase in SOD activity in the lens capsule of patients with PEX and cataract suggests that oxidative mechanisms play a role in the etiopathogenesis of cataract in PEX. This suggests that SOD activity may be increased as a compensatory mechanism to eliminate this oxidative stress.

Aged↗

PubMed2006

Corneal thickness measurements in normal and keratoconic eyes: Pentacam comprehensive eye scanner versus noncontact specular microscopy and ultrasound pachymetry.

PURPOSE: To compare central corneal thickness (CCT) measurements taken with the Pentacam comprehensive eye scanner (CES), noncontact specular microscopy (SM), and ultrasound pachymetry (UP) in normal and keratoconic corneas. SETTING: Department of Ophthalmology, Ankara University School of Medicine, Ankara, Turkey. METHODS: In a prospective study, 3 CCT measurements were taken with the Pentacam CES, SM, and UP in that sequence from 1 eye of 45 consecutive patients with myopia (group A) and 62 consecutive patients with keratoconus (group B). Eyes with keratoconus were further divided into 3 subgroups, mild, moderate, and severe, according to the mean keratometry readings. RESULTS: Pentacam CES (r = 0.994) and UP (r = 0.993) demonstrated very high and comparable reproducibility in group A. In group B, Pentacam CES displayed better reproducibility (r = 0.988) than UP (r = 0.969) and SM (r = 0.901). The mean CCT measurements of Pentacam CES and UP were not significantly different in group A (P = .37) and in eyes with mild keratoconus (P = .29), whereas significant differences between all instrument pairs were evident in group B and in moderate and severely keratoconic eyes (P<.05). Noncontact SM measurements were significantly smaller than those of Pentacam CES and UP in all groups (P<.05) when a measurement could be obtained. There were significant linear correlations between CCT measurements of Pentacam CES, UP, and noncontact SM in groups A, B, and mildly keratoconic eyes (P<.001). CONCLUSIONS: Results suggest that whereas Pentacam CES and UP may be used interchangeably in normal eyes in the clinical setting for the measurement of CCT, one should be cautious interpreting corneal thickness data from Pentacam CES, UP, and particularly SM in eyes with keratoconus. Whereas, in normal and mildly keratoconic eyes, Pentacam CES and UP demonstrated very high and comparable reproducibility, in moderately keratoconic eyes, Pentacam CES readings showed better reproducibility than UP.

Adolescent↗

PubMed2006

Contact lens fitting for keratoconus after Intacs placement.

PURPOSE: To describe a patient with keratoconus who underwent Intacs surgery to one eye with an unsatisfactory result and refused to undergo an Intacs removal procedure. METHODS: Case report. RESULTS: The patient's eye was fitted with a soft contact lens for visual rehabilitation 5 months after Intacs placement. CONCLUSIONS: Intacs, with the help of secondary refractive procedures or contact lenses, may still be considered as effective in postponing penetrating keratoplasty, even in patients with advanced keratoconus.

Adult↗

PubMed2006

In vivo confocal microscopy findings in keratoconus.

PURPOSE: : To evaluate corneal structure in eyes with keratoconus by using in vivo confocal microscopy. METHODS: : In a prospective institutional study, 48 eyes of 24 consecutive patients with keratoconus were examined by in vivo confocal microscopy. Forty-four eyes of 22 healthy subjects served as the control. The main outcome measures were qualitative and quantitative changes encountered at confocal microscopy examination. RESULTS: : In the keratoconus group, in vivo confocal microscopy findings included elongated, exfoliating superficial epithelial cells; brightly reflective material deposition within the basal epithelial cells; prominent, thickened subbasal nerves; structural changes in subbasal nerve fibers; pronounced reflectivity and irregular arrangement of stromal keratocytes; structurally abnormal anterior stromal keratocyte nuclei; folds in the anterior, mid, and posterior stroma; folds in Descemet's membrane; pleomorphism and enlargement of endothelial cells; and endothelial guttata. No such abnormal findings were present in the control group. There were significant differences between the two groups in terms of the mean basal epithelial, anterior and posterior stromal keratocyte densities, the mean basal epithelial cell area, and the mean endothelial cell hexagonality percentages. CONCLUSIONS: : Quantitative and qualitative structural changes were observed in all corneal layers in eyes with keratoconus by using slit-scanning confocal microscopy. The changes at all levels were more prominent in eyes with severe keratoconus. This noninvasive in vivo technique may prove to be useful in the diagnosis and follow-up of keratoconus and in the understanding of its pathophysiology.

Adolescent↗

PubMed2006

Clinical and in vivo confocal microscopy findings in patients receiving tamoxifen citrate.

PURPOSE: : To describe the deposition rate of tamoxifen in the cornea and observe its impact on the cornea with confocal microscopy. METHODS: : Forty-four eyes of 22 women receiving tamoxifen at a dosage of 20 mg/day for at least 6 months for the adjuvant treatment of breast cancer and 30 eyes of 15 healthy age-matched women were examined for corneal drug deposition by slitlamp after pupil dilation. Ultrasound pachymetry, specular microscopy, in vivo confocal microscopy, and Schirmer tear test were also performed in all patients. RESULTS: : The mean duration of tamoxifen intake was 21.6 +/- 7.9 months (range, 13-44 months), and the mean cumulative dose was 12.9 +/- 4.7 g (range, 7.8-26.4 g). Drug depositions in the inferior paracentral cornea were identified in 32 (72%) eyes at pupil-dilated slitlamp examination. There were no significant differences between eyes with keratopathy, those without keratopathy, and control eyes in regard to the mean Schirmer test scores, mean central corneal thickness, mean endothelial cell count, mean basal epithelium cell density, mean anterior and posterior stromal keratocyte density, and mean endothelial cell density (P > 0.05). No pathologic alteration of structure was observed with in vivo confocal microscopy at any corneal level in patients receiving tamoxifen. CONCLUSIONS: : Low-dose tamoxifen use was associated with corneal depositions in 72% of patients. Slitlamp examination performed with pupil dilation was helpful in detection of subtle tamoxifen-related deposits. Amelioration of in vivo confocal microscopy systems may be helpful in accurate imaging of the paracentral and peripheral cornea.

Adult↗

PubMed2006

Combined "symmetrical conjunctival flap transposition" and intraoperative low-dose mitomycin C in the treatment of primary pterygium.

PURPOSE: To introduce a new technique of conjunctival reconstruction after primary pterygium excision, and to evaluate the efficacy of combined "symmetrical conjunctival flap transposition" and intraoperative low-dose mitomycin C application in preventing recurrence of primary pterygium. METHODS: In a prospective, non-comparative case series, 43 eyes of 41 consecutive patients with primary pterygium were studied. In all patient eyes, after excision of pterygia, 0.02% mitomycin C was applied topically for 2 min over the exposed scleral surface and "symmetrical conjunctival flap transposition" was performed to reconstruct the conjunctival defect. The main outcome measures were pterygium recurrence or any complications related with surgery or mitomycin C. RESULTS: The mean age of the patients was 47.5 +/- 12.4 years (range 30-70 years). Among the 38 patients who were not lost to follow up, three patient eyes (7.5%) had grade 1, 24 eyes (60.0%) had grade 2 and 13 eyes (32.5%) had grade 3 pterygium. The mean follow up was 12.2 +/- 5.7 months (range 7-28 months). No recurrence or sight-threatening complications were encountered in any patient eye throughout the follow-up period. CONCLUSION: Combined "symmetrical conjunctival flap transposition" and intraoperative low-dose mitomycin C application may be an effective surgical alternative in preventing recurrence of primary pterygium. Although the procedure seems to be free from severe complications, surgeons and patients should be well aware of the risk of late radiomimetic complications of mitomycin C. Comparative, randomized trials with more number of patients and longer follow up are required to further establish the safety and efficacy of this treatment strategy.

Administration, Topical↗

PubMed2005

Amiodarone keratopathy: an in vivo confocal microscopy study.

PURPOSE: To evaluate the characteristics and evolution of corneal morphologic changes induced by systemic amiodarone treatment by using in vivo slit scanning confocal microscopy in an attempt to understand the pathogenesis of corneal and other systemic side effects of this drug. METHODS: Forty-nine eyes of 25 consecutive subjects receiving amiodarone therapy (group A) and 26 eyes of 13 age- and sex-matched healthy control subjects (group B) were enrolled in the study. RESULTS: In group A, the mean dosage of amiodarone was 224.0 +/- 71.3 mg, and the mean duration of treatment was 21.3 +/- 20.9 months. In eight (8 of 49,16.3) eyes of four patients, no deposition was observed, neither by slitlamp nor by confocal microscopy. The deposition could be detected as early as 2 months after the onset of treatment in 41 (41 of 49, 83.7%) eyes, by slitlamp and confocal microscopy. Deposition was significantly correlated with the duration of treatment and, therefore, the cumulative dose of the drug ingested. Deposits were observed as bright, hyper-reflective spots that were localized intracellularly and were present at the level of basal lamina of all 41 (100%) corneas in which deposition could be observed at confocal microscopy. Deposits were also observed in the superficial epithelium, anterior stroma, mid stroma, and subepithelial nerves in eyes with grade 2 to 4 keratopathy. Additionally, morphologic abnormalities were observed in anterior stromal keratocytes, subepithelial and stromal nerves, and endothelium. The mean anterior and posterior keratocyte densities were statistically significantly higher than those in group B. CONCLUSIONS: In addition to showing drug deposition does not seem to occur before 2 months of treatment and does not seem to be correlated with tear function. Although the clinical significance of morphologic changes induced by the drug is known and although deposition could not be detected before it was evident with slitlamp biomicroscopy, with some improvement in instrumentation, the authors believe that confocal microscopy will also prove to be useful in early diagnosis and in understanding the pathophysiology of amiodarone keratopathy. This may help grow insight to the mechanism of other, sometimes lethal, systemic side effects of this drug.

Adult↗

PubMed2005

Macular edema and iridocorneal endothelial syndrome: a case report.

PURPOSE: To report a case of cystoid macular edema (CME) in iridocorneal endothelial syndrome. METHODS: Case report. RESULTS: The authors describe the clinical history and ocular examination of a 38-year-old woman with iridocorneal endothelial syndrome and CME. This association has never been reported before. The mechanism of CME is unknown. CONCLUSION: CME may cause visual deterioration in iridocorneal endothelial syndrome. We emphasize the importance of posterior segment examination in these cases.

Adult↗

PubMed2005

In vivo confocal microscopy of megalocornea with central mosaic dystrophy.

In vivo confocal microscopy was performed on the central cornea of both eyes of a patient with megalocornea and central mosaic dystrophy. In the stroma, starting just below Bowman's membrane, polygonal, moderately reflective areas of opacification separated by diagonal hyporeflective striations were observed. The opaque areas appeared smaller in the anterior stromal layers and seemed to get larger towards the posterior stroma. The epithelium, Bowman's membrane and endothelium appeared normal. In vivo confocal microscopy is helpful in evaluating the morphological characteristics of corneal dystrophies, degenerations or developmental abnormalities of the cornea, and may prove to be helpful in understanding their pathophysiology.

Cell Count↗

PubMed2003

Therapeutic use of Focus Night & Day contact lenses.

PURPOSE: To evaluate the safety and efficacy of Focus Night & Day extended-wear contact lenses when used for therapeutic purposes. METHODS: Fifty eyes of 50 consecutive patients presenting at the Ankara University Medical Center, Cornea and Contact Lens Service, and requiring bandage contact lens use for ocular surface disorders, were enrolled. All patients were fitted with Focus Night & Day contact lenses and were followed in regard to patient satisfaction, contact lens fit and performance, and success of treatment. RESULTS: Twenty-four patients (48%) were male, and 26 (52%) were female. Average age at the time of presentation was 46.9 +/- 21.6 years (range 1.5 to 88 years). Therapeutic contact lens indications included Fuchs' dystrophy (2 eyes), toxic epitheliopathy (1 eye), filamentous keratopathy (2 eyes), corneal perforation (2 eyes), corneal stromal melting (2 eyes), recurrent corneal erosion (4 eyes), chemical or traumatic epithelial defect (3 eyes), epithelial irregularity (1 eye), persistent epithelial defect (4 eyes), lamellar laceration (5 eyes), graft insufficiency (2 eyes), pseudophakic bullous keratopathy (7 eyes), aphakic bullous keratopathy (4 eyes), disciform keratitis (1 eye), postkeratectomy (4 eyes), and post-amniotic membrane transplantation or post-limbal autograft transplantation (6 eyes). Mean duration of continuous contact lens wear was 2.4 +/- 3.0 months (range 3 days to 12 months). At the end of the follow-up period, the mean change in visual acuity was a gain of 1.8 +/- 2.8 logMAR units (0-9 Snellen lines). No sight-threatening complications related to contact lens wear were encountered. A culture-negative sterile corneal infiltrate developed in one patient and was treated with cessation of lens wear and subsequent topical antibiotic and steroids. CONCLUSION: Focus Night & Day contact lenses are safe and effective when used for therapeutic purposes. Infrequent replacement of these lenses seems to be especially advantageous in patients for whom frequent lens insertion and removal may be associated with epithelial trauma, pain, and a potential increase in infection risk. Infrequent replacement of these lenses also decreased the office time and the cost of treatment without an increase in hypoxia-related complications.

Adolescent↗

PubMed2002

Corneal topographic changes after retinal detachment surgery.

PURPOSE: To evaluate the changes in corneal topography after scleral buckling surgery for retinal detachment. METHODS: Twenty-one eyes of 21 patients with the diagnosis of retinal detachment were included in this prospective study. Scleral buckling surgery was performed on all patients. The corneal topography of each was measured before surgery and at 1 week and 1 and 6 months after surgery by computer-assisted videokeratoscopy using the EyeSys 2000 Corneal Analysis System. Changes in corneal videokeratographies were analyzed using the Holladay Diagnostic Summary (HDS) software package. RESULTS: A statistically significant central corneal steepening (average, 1.8 diopter) was noted 1 week after surgery. The total and irregular astigmatic components both revealed a significant but transient increase in the first postoperative month. All these topographic changes persisted for as long as 6 months but returned to preoperative values afterward. CONCLUSION: Scleral buckling was found to induce transient changes in corneal topography producing both myopia and corneal astigmatism. Videokeratography is helpful for documenting such corneal changes after scleral buckling surgery for retinal detachment.

Aged↗