-
[show abstract]
[hide abstract]
ABSTRACT: To report the perioperative complications and clinical outcomes of 50 deep anterior lamellar keratoplasty (DALK) cases.
Fifty eyes of 50 patients with pathologies involving the corneal stroma and sparing the Descemet's membrane and endothelium were included consecutively in this prospective, noncomparative interventional case series study. DALK was performed using the big-bubble technique.
The most frequent indication for DALK surgery was keratoconus (26 eyes), followed by corneal dystrophy (10 eyes) and superficial corneal scar (14 eyes). The average follow-up period was 12.0 ± 3.9 months. DALK was completed in 41 cases (82%). A big bubble was achieved successfully in 37 cases (74%). Descemet's membrane perforations occurred in 14 (28%) eyes, 8 of which were macroperforation and necessitated conversion to penetrating keratoplasty. Complications tended to decrease throughout the study. Postoperative best-corrected visual acuity of 0.5 or better was present in 30 of 41 (73.2%) eyes that underwent DALK. There was no episode of graft rejection.
DALK big-bubble technique may be a valuable procedure during transition from penetrating keratoplasty to anterior lamellar keratoplasty. It provided acceptable visual and refractive outcome even during the learning period in a variety of corneal lesions.
Ophthalmic Surgery Lasers and Imaging 09/2010; 41(6):642-50. · 0.62 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Glaucoma is a progressive optic neuropathy and is the leading cause of blindness in the United States and other industrialized countries. Elevated pressure in the eye is a risk factor for glaucoma and indeed experimental studies of induced pressure elevation in nonhuman primate's results in typical glaucomatous optic nerve damage. However, normal intraocular pressure can also lead to loss of vision in glaucoma. Although the initiating causes leading to glaucoma are unknown, oxidative and nitrative stress appears to play a role in the progressive neuronal death that is characteristic of glaucomatous optic nerve damage. Increased markers of oxidative stress that have been reported in glaucoma include protein nitrotyrosine, carbonyls in proteins, lipid oxidation products and oxidized DNA bases. Studies have also highlighted the role of nitric oxide in glaucoma by reporting the presence of inducible nitric oxide synthase in the iris-ciliary body, retina and in the glaucomatous optic nerve head of experimental rat models. This review discusses the role of reactive oxygen and nitrogen species in the pathogenesis of glaucoma and examines the relevance of antioxidants in neurodegeneration associated with the disease. It is concluded that oxidative and nitrative stress have a pathogenic role in glaucoma.
Free Radical Biology and Medicine 09/2008; 45(4):367-76. · 5.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To investigate which visual field testing strategy yields more reliable and tolerable field analysis in a normal pediatric population.
68 healthy children aged 6-13 years with no ocular or systemic diseases were included in the study. One randomly selected eye of each child underwent standard achromatic visual field analysis using a Model 750 Humphrey Field Analyzer II (Carl Zeiss Meditec, Dublin, Calif., USA). We evaluated the reliability criteria (false negative, false positive and fixation loss scores) and the duration of the visual field tests performed by Fastpac (with stimulus sizes III and V, respectively) and SITA Fast with stimulus size III. Moreover, subjects underwent Goldmann perimetry testing with stimulus V. Ability to complete the perimetry tests was also scored. Perimetric analysis was stopped before the end if signs of fatigue appeared. Mean sensitivity, mean defect and pattern standard deviation were recorded for automated tests.
All subjects but 8 successfully completed each of four tests. The mean duration of the tests was 4.23, 5.46, 6.35 and 11.06 min for SITA Fast with stimulus size III, Fastpac with stimulus size V, Size III and Goldmann perimetry, respectively (p < 0.001). Both false-negative and false-positive test scores were found to be significantly lower for SITA Fast with stimulus size III compared to the other automated tests (p < 0.01). Children older than 8 years (n = 35) achieved significantly higher test reliability scores (p < 0.01).
As early detection of structural and functional visual abnormalities may be of utmost importance in the pediatric population considering many potentially serious neurological and ocular problems met with, accurate and reproducible visual field testing is vital. To achieve this goal, visual field testing with SITA Fast algorithm seemed to be a promising strategy for a pediatric population in a typical clinical setting.
Ophthalmologica 07/2008; 222(5):329-33. · 1.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Increased expression of inducible nitric oxide synthase (NOS-2) in inflammatory diseases like uveitis suggests that it contributes to the observed pathological state. The aim of this study was to evaluate corneal expression of NOS-2 and corneal protein nitration in a rat model of uveitis. A single injection of intravitreal lipopolysaccharide was used to induce uveitis. Corneal proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and visualized by Coomassie blue staining. Expression of NOS-2 and nitrotyrosine (NO(2)Tyr) formation were determined via immunohistochemistry and Western blot analysis. Total nitrate/nitrite levels in the vitreous were measured by spectral analysis via the Griess reagent. Immunohistochemical analysis revealed increased corneal NOS-2 and NO(2)Tyr immunoreactivity in rats with uveitis compared with controls. NOS-2 and NO(2)Tyr immunoreactivity was observed in and around basal cells in the corneal epithelium. Western blot analysis of corneal lysates showed multiple nitrated protein bands in uveitic rats. Spectrophotometric measurement of total nitrate/nitrite levels in the vitreous affirmed significantly increased levels of nitric oxide generation in uveitis (126 +/-2.63 microM/mg protein) compared with controls (65 +/-6.57 microM/mg protein). The presented data suggests that extensive formation of protein nitration and reactive nitrogen species in the cornea contributes to tissue destruction in uveitis. Hence, selective inhibition of NOS-2 may prevent long-term complications and lead to an improvement in the management of uveitis.
Experimental Biology and Medicine 12/2007; 232(10):1308-13. · 2.64 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the effect of the menstrual cycle and gender on right and left visual hemifields in healthy subjects.
One randomly selected eye from each of 42 healthy normally menstruating women and of 37 men with no systemic and ocular problems, other than refractive error, were included in the study. Subjects underwent complete ocular examination and standard acromatic perimetric (SAP) and short-wavelength automated perimetric (SWAP) analysis in both follicular (7th to 10th day of the cycle) and luteal phases (days 3 to 7 before the menstrual bleeding) of the menstrual cycle. Visual field analysis was performed using Model 750 Humphrey Field Analyzer II (Carl Zeiss Meditec, Dublin, CA, USA) with full-threshold, central 30-2 program.
The mean age of female (n = 42) and the male subjects (n = 37) were 35.2 +/- 3.1 years and 34.8 +/- 2.9 years, respectively (p = 0.58). Neither females nor males showed any statistically significant differences in the right and left hemifield tests with SAP (both p values > 0.05). However, using SWAP, in luteal phase of female subjects, left hemifield sensitivity was significantly less than (with a mean of 0.47 dB) right hemifield. In follicular phase, there was no significant interhemifield difference (p > 0.05). Male subjects did not show any significant differences between the sensitivity of the two hemifields with SWAP tests.
There has been a significant difference between the mean SWAP sensitivity of right and left visual hemifields in luteal phase of the menstrual cycle. In case of a suspected hemifield difference, SAP rather than SWAP may be used to confirm suspected neurological defects as SAP is not affected by the menstrual cycle.
Current Eye Research 09/2005; 30(9):807-11. · 1.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated the effect of pregnancy on the long-term fluctuation of retinal sensitivity in healthy women.
Candidates for the study were healthy women who were likely to become pregnant. A complete ocular examination of both eyes was performed in 41 women, and 1 eye each was chosen at random for the study. This initial examination included 2 sets of visual field measurements consisting of 5 individual measures done at least a day apart. After pregnancy, ocular examinations were repeated once between 10 and 15 weeks of gestation and once between 29 and 34 weeks. The mean threshold sensitivity (MS) of the visual field and the coefficient of variation of MS measurements for upper temporal, upper nasal, lower temporal, and lower nasal quadrants were calculated in each series.
The visual field MS of the subjects increased significantly in the third trimester (p < 0.01). The coefficient of variation of the visual field MS measurements did not change significantly in the nasal quadrants. However, it decreased significantly in both upper and lower temporal quadrants.
Visual field MS and the reproducibility of MS measurements for temporal visual field increased significantly in the third trimester of the pregnancy. Further studies on the role of pregnancy-related ocular hemodynamic changes may provide insight into the etiopathogenesis of hormone-related processes.
Canadian Journal of Ophthalmology 09/2005; 40(4):487-91. · 1.47 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The purpose of this study was to examine and compare menstrual-cycle-dependent topographic changes in the optic nerve head of normally menstruating women with different grades of type 2 diabetes mellitus.
We studied the right eyes of 123 normally menstruating women (36 with severe nonproliferative diabetic retinopathy [NPDR], 42 with mild NPDR and 45 healthy subjects). All subjects underwent a complete ocular examination at baseline. At 4 hormonally distinct phases of the menstrual cycle (early follicular, late follicular, mid-luteal and late luteal), we analysed the topography of the optic nerve head, using a confocal scanning laser ophthalmoscope, and measured the serum levels of estradiol, progesterone and luteinizing hormone.
We excluded from analysis the data for 8 patients with severe NPDR, 10 patients with mild NPDR and 15 control subjects who were lost to follow-up examinations during the menstrual cycle. The mean age and optic disc area did not differ significantly among the 3 groups. The duration of diabetes was significantly longer in the patients with severe NPDR than in those with mild NPDR (p < 0.05). The women with severe NPDR had a significantly increased neuroretinal rim area and a significantly decreased cup-shape measure, linear cup/disc ratio, cup/disc area ratio and cup area in the late luteal phase compared with the other phases of the menstrual cycle (p < 0.05). Those with mild NPDR or a normal retina had no significant topographic changes in the optic nerve head during the menstrual cycle.
Severe NPDR is associated with significant topographic changes in the rim and cup of the optic nerve head during the menstrual cycle. This must be considered in the evaluation of women with both diabetes and glaucoma. The normal fluctuations in serum sex hormone levels during the menstrual cycle of diabetic women seem to affect the optic nerve head more when the disease is advanced.
Canadian Journal of Ophthalmology 05/2005; 40(2):175-82. · 1.47 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the effect of the menstrual cycle on the optic nerve head topographic analysis of normally menstruating migrainous women.
Randomly selected one eye of 44 migrainous and 49 healthy control women with regular menstrual cycles were included in the study. All subjects underwent complete ocular examination. Optic nervehead topographic analysis were performed using a confocal scanning laser ophthalmoscope, HRT II (Heidelberg Retinal Tomograph II, software version 1.6;Heidelberg Engineering, Heidelberg, Germany). They were repeated for two times during the menstrual cycle: in follicular phase (7th to 10th day of the cycle) and in the luteal phase (days 3 to 4 before the menstrual bleeding). Serum estradiol, progesterone, and luteinizing hormone measurements were repeated at each menstrual phase. Results: The mean age of migrainous and control subjects were 31.5 + 5.1 years and 33.4 +/- 3.7 years, respectively (P > 0.05). Their mean disc areas were 2.26 +/- 0.46 mm(2) and 1.95 +/- 0.39 mm(2), respectively(P < 0.05). Control subjects did not demonstrate any difference in the disc topography (P > 0.05). The parameter rim volume decreased, while the parameters cup volume and cup shape measure increased significantly in the luteal phase of the migrainous women (all P values <0.05). Mean intraocular pressure of the migrainous women decreased significantly in luteal phase (P < 0.05).
Significant differences exist in the optic rim and cup parameters during the menstrual cycle of the migrainous women. Further clinical trials on ocular blood flow changes during the menstrual cycle of the migrainous women may highlight the role of sex steroids in the optic nerve head of the migrainous women.
Current Eye Research 03/2005; 30(3):163-9. · 1.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the long-term systemic toxicity of tacrolimus (FK-506) administered by various routes, and to assess the effect of dose reduction on toxicity.
The study animals were 120 experimentally naive adult female Wistar rats weighing 200-250 g each. The rats were randomly divided into 10 equal groups (n=12 in each) and treated with tacrolimus administered topically (in drops, 0.3%, q.i.d.), intravitreally (0.5 mg/kg bodyweight/week), intramuscularly (1 mg/kg bodyweight/week), low-dose intravenously (1 mg/kg bodyweight/week) and in high-dose intravenously (2 mg/kg bodyweight/week) for 3 months. The rats in the control groups (one for each different route of administration) were treated with 0.9% NaCl. The blood concentration of tacrolimus, complete blood count and biochemistry parameters were measured each month for the 3-month study period.
The rats in the control groups and experimental groups administered topical and intravitreal tacrolimus did not demonstrate any systemic toxic effects. The rats that developed certain toxic effects (hyperglycaemia, hyperkalaemia and nephrotoxicity) in the groups given low-dose or high-dose i.v. tacrolimus responded well to dose reduction. Following dose reduction, blood glucose concentrations decreased from 247.4 +/- 42.3 mg/dL to 189.6 +/- 37.9 mg/dL (P <0.05), and from 237.4 +/- 41.1 mg/dL to 182.3 +/- 22.7 mg/dL (P <0.05) in the low- and high-dose i.v. tacrolimus-treated rats, respectively. The rats that developed impaired hepatic function after high-dose tacrolimus did not respond to dose reduction. Baseline cholesterol concentrations for the intramuscular and low- and high-dose i.v. tacrolimus-treated groups, demonstrated decreases, respectively, from 87.4 +/- 14.0 mg/dL, 86.4 +/- 14.0 mg/dL and 90.4 +/- 14.3 mg/dL to 53.6 +/- 9.8 mg/dL, 52.1 +/- 12.5 mg/dL and 63.5 +/- 11.7 mg/dL by the end of the second month. The differences were found to be statistically significant (P <0.05 for each result).
Topical or intravitreal administration of tacrolimus seems to be systemically safe whereas parenteral administration can cause some systemic haematological changes such as dose-dependent decreased serum cholesterol concentrations. Dose reduction may prevent such adverse effects.
Clinical and Experimental Ophthalmology 03/2005; 33(1):53-9. · 1.98 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: It has been postulated that migraine and glaucoma may have common vascular causative factors. Significant sex-based differences in the incidence of many important ocular conditions raise the possibility that estrogens may have direct effects on the eye. We performed a study to determine the effect of the menstrual cycle on standard achromatic automated perimetry (SAP) and short-wavelength automated perimetry (SWAP) (blue-on-yellow perimetry) of women with migraine.
Both eyes of 73 normally menstruating women (31 subjects with migraine and 42 healthy control subjects) were included in the study. Subjects underwent a complete ocular examination including SAP and SWAP in both the follicular phase (12th to 13th day of the cycle) and the luteal phase (1 to 2 days before the onset of bleeding) of two consecutive menstrual cycles.We performed visual field analysis using the Humphrey Field Analyzer II with the full-threshold central 30-2 program. Mean sensitivity was calculated for the superior temporal, inferior temporal, superior nasal and inferior nasal regions separately.
Thirteen subjects were lost to follow-up (5 in the migraine group and 8 in the control group), leaving 26 subjects and 34 subjects respectively. There was no significant difference in mean age between the two groups (33.9 years [standard deviation (SD) 3.4 years] vs. 35.1 years [SD 3.3 years]). The mean duration of migraine was 7.6 (SD 3.1) years (range 3-14 years). In both groups, serum estradiol levels were significantly lower (p = 0.001) and serum progesterone levels were significantly higher (p < 0.001) in the luteal phase than in the follicular phase. In the control group, the mean sensitivity values with SWAP were significantly lower in the luteal phase than in the follicular phase (p = 0.04). A similar decrease was observed for the subjects with migraine with both SAP and SWAP (p = 0.01). There was no difference in regional mean sensitivity between the two phases with either perimetric test in the control group. For the subjects with migraine, there was no difference in regional mean sensitivity between the two phases with SAP. However, with SWAP, the mean sensitivity for the nasal visual field locations was significantly lower in the luteal phase than in the follicular phase (p = 0.01).
Our study provides further evidence of an effect of sex hormones on the visual field of women with migraine. In addition to assessment of intraocular pressure, menstrual cycle phases should be considered in women with migraine at risk for glaucomatous optic neuropathy.
Canadian Journal of Ophthalmology 02/2005; 40(1):51-7. · 1.47 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the effect of the menstrual cycle on optic nerve head topographic analysis in normally menstruating, healthy women.
The study included single eyes selected randomly from each of 52 healthy women with regular menstrual cycles. All subjects underwent a complete ocular examination. Optic nerve head topographic analyses were performed using a confocal scanning laser ophthalmoscope, the Heidelberg Retinal Tomograph II (HRT II, software version 1.6). The analyses were repeated three times during the menstrual cycle: in the follicular phase (days 7-10 of the cycle), at ovulation, and in the late luteal phase (days 1-3 before menstrual bleeding). Serum oestradiol, progesterone and luteinizing hormone levels were measured at each menstrual phase.
Fourteen subjects were excluded from the study. The mean age of the subjects (n = 38) was 25.6 +/- 3.7 years (range 21-34 years). Blood oestradiol levels were significantly lower in the late luteal phase (35.8 pg/ml) (p < 0.0001). The mean disc area of the subjects was 1.94 +/- 0.33 mm(2). The neuroretinal rim area decreased significantly during the luteal phase (p < 0.001). However, the linear cup : disc ratio, cup : disc area ratio and the cup area were significantly higher during the luteal phase (p < 0.001).
These observations raise the possibility that sex hormone fluctuations which occur during a normal menstrual cycle in healthy women significantly alter neuroretinal rim area and cup variables of the optic nerve head. These findings should be taken into consideration in the clinical follow-up of young women with glaucoma.
Acta Ophthalmologica Scandinavica 01/2005; 82(6):741-5. · 1.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To assess the disc area, age, sex, laterality (side of the eyes) and refractive error dependent differences in optic nerve head topographic parameters in a normal population.
Optic nerve head topographic analysis of both eyes of 551 healthy Turkish subjects aged 11-75 years (1102 eyes) was performed using a confocal scanning laser ophthalmoscope, the Heidelberg Retinal Tomograph II (HRT II). The effects of disc size, sex, laterality (side of the eyes), age and refractive error on optic nerve head topographic parameters were assessed. Subjects were divided into three different age groups (<30 years, 30-60 years, >60 years) and three different disc area groups (<2.00 mm(2), 2.00-2.25 mm(2), >2.25 mm(2)). Disc area, topography standard deviation and a total of 12 topographic parameters were calculated by HRT II for each subject. Statistical analysis was performed using Student's t-test, multiple regression analysis, Tukey-HSD test, anova and Pearson's correlation coefficient.
A total of 543 subjects (298 women and 245 men) were included in the study. The mean disc area of the subjects was 2.12 +/- 0.47 mm(2) (range 1.16-4.98 mm(2)). The mean refractive error of the subjects was -0.58 +/- 1.71 D (range -4.75 D to +4.25 D). The mean cup shape measure was -0.21 +/- 0.07 (95% confidence interval -0.07 to -0.35). The disc area was significantly correlated with all of the topographic parameters but two; namely, the cup shape measure and the height variation contour. Significant age-related differences were detected in four parameters (mean retinal nerve fibre layer [RNFL] thickness, disc area, cup-to-disc area ratio, cup area) and significant sex-related differences were detected three parameters (mean RNFL thickness, height variation contour, RNFL cross-sectional area). However, there were no significant differences in any of the parameters for laterality and refractive error. The parameter cup shape measure did not correlate with any of the five variables investigated.
Cup shape measure was the only optic nerve head topographic parameter that was independent of age, sex, disc area, laterality and the refractive error. It seems to be a promising parameter in evaluation and comparison of the optic discs of normal subjects, with different disc area, age, sex, refraction error and laterality, as being independent of the main variation factors of the disc topography.
Clinical and Experimental Ophthalmology 06/2004; 32(3):259-64. · 1.98 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the effect of menstrual cycle phases on the visual field analysis of healthy females.
One randomly selected eye each of 59 healthy normally menstruating women, and of 54 men with no systemic and ocular problems, other than refractive error, were included in the study. Subjects underwent complete ocular examination, and standard achromatic perimetric (SAP) and short-wavelength automated perimetric (SWAP) analysis in both follicular (7th to 10th day of the cycle) and luteal phases (days 3-7 before the menstrual bleeding) of the menstrual cycle. Visual field analysis was performed using a Model 750 Humphrey Field Analyzer II (Humphrey Instruments Inc., San Leandro, Calif., USA) with full-threshold, central 30-2 program. Visual fields were divided into four regions as superior temporal, inferior temporal, superior nasal and inferior nasal, respectively.
The mean age of female (n = 59) and the male subjects (n = 54) were 34.6 +/- 2.9 and 35.0 +/- 2.7 years, respectively (p = 0.49). SWAP tests demonstrated a significantly decreased mean MS value in the luteal phase (p < 0.05). However, it did not change significantly with SAP tests. Regional MS values of both SAP and SWAP tests were not different in both phases of the menstrual cycle (all p values >0.05). Mean perimetric test durations obtained with both SAP and SWAP were not different throughout the menstrual cycle (both p values >0.05).
Clinicians should verify menstrual status when evaluating a suspected loss of visual field sensitivity in menstruating women. The findings of the present study suggest that the SWAP test may be more sensitive to determine subtle sex hormone-dependent changes in visual field analysis of healthy women.
Ophthalmologica 219(1):30-5. · 1.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the effect of pregnancy on intraobserver and intertechnique agreement for intraocular pressure (IOP) measurements.
Right eyes of 88 healthy women who were likely to become pregnant and of 94 healthy age-matched females were included in the study. Complete ocular examinations were performed on each eye. IOP measurements were obtained by Goldmann, Schiotz and non-contact tonometers (NCT) during 3-week exam periods before (within 6 weeks of conception) and during pregnancy (first, second and third trimesters) for pregnant cases, and in similar time intervals for control subjects. In each exam period, three readings with each of three separate tonometers were obtained, at least 1 day apart. Intraobserver and intertechnique agreements for IOP measurements were assessed.
The mean visual acuity, keratometry and refractive error of both control and pregnant subjects did not change significantly during the study (all p values >0.01). In late pregnancy, pregnant cases demonstrated significant decreases in IOP measurements obtained with each of the three tonometers, and in intraobserver agreement with Goldmann and Schiotz tonometers (all p values <0.01). Intertechnique agreement of both Goldmann and Schiotz tonometers with NCT decreased significantly in the third trimester. Both intraobserver and intertechnique agreement in IOP measurements of control subjects were not found to change significantly during the study (all p values >0.01).
IOP significantly decreased in the third trimester of pregnancy. Perfect intraobserver agreement in IOP readings of pregnant subjects was obtained with NCT. This may suggest that NCT is a viable option for IOP measurements during the follow-up of pregnant patients at risk for glaucoma.
Ophthalmologica 219(1):36-42. · 1.42 Impact Factor
