Nurullah Cagil

Relation between corneal thickness and intraocular pressure measurement by noncontact and applanation tonometry

Purpose: To assess whether there is a significant difference in intraocular pressure (IOP) measurements between noncontact and applanation methods and if so, whether the difference is correlated with corneal thickness. Setting: Iş&igr;k Eye Clinic, Ankara, Turkey. Methods: This prospective study comprised 120 eyes of 60 randomly selected patients. Noncontact tonometry, applanation tonometry, and pachymetry were performed in each eye. The results were compared and an analysis was performed to determine whether there was a correlation between the differences in IOP measurements and corneal thickness in the entire group and in subgroups composed of the halves and quarters of the group. Results: The mean IOP in the entire group was 20.38 mm Hg ± 4.97 (SD) with the noncontact tonometer and 18.84 ± 4.47 mm Hg with the Goldmann applanation tonometer. The difference between the measurements with the noncontact method and those with the applanation method was statistically significant (P < .01) except in cases having a corneal thickness between 513 &mgr;m and 539 &mgr;m (P gt; .01). There was a positive correlation between corneal thickness and the difference in measurements by noncontact and applanation tonometry, and the magnitude of correlation was greater in cases with thicker corneas. Conclusion: The reliability of tonometers decreased with increasing corneal thickness, in which case higher readings were found, especially with the noncontact tonometer.

Correlation between intraocular pressure and corneal stromal thickness after laser in situ keratomileusis

Purpose: To assess the relationship between intraocular pressure (IOP) and corneal stromal thickness following laser in situ keratomileusis (LASIK) for myopia or myopic astigmatism. Setting: Private clinic in Turkey. Methods: The database of patients who had LASIK was retrospectively reviewed. Preoperative and postoperative IOP and corneal thickness were measured in both eyes of 353 patients by noncontact tonometry and ultrasonic pachymetry, respectively. The correlation between changes in IOP and corneal thickness was evaluated by regression analysis. Results: Laser in situ keratomileusis was associated with a mean decrease in pachymetry of 46.7 &mgr;m ± 28.9 (SD) and a mean decrease in IOP of 2.8 ± 2.1 mm Hg. There was a significant correlation between the decreases in IOP and pachymetry (P < .001). Conclusion: The decrease in IOP after LASIK was related to the decrease in corneal stromal thickness, although there may be other contributing factors.

Outcome of flap subluxation after laser in situ keratomileusis : Results of 6 month follow-up

PURPOSE To evaluate the long-term outcome in cases with flap subluxation after laser in situ keratomileusis (LASIK). SETTING Private clinic in Turkey. METHODS Data of all patients who had LASIK were documented and the follow-ups of those who had flap subluxation evaluated. The number of LASIK cases was 1481 and the number of flap subluxations, 21. Laser in situ keratomileusis was performed with the Moria microkeratome and the VISX Twenty/Twenty B excimer laser using a multizone profile and the sutureless hinged corneal flap technique. RESULTS The incidence of flap subluxation was 1.42%. Statistical analysis of uncorrected visual acuities, best corrected visual acuities, and mean spherical equivalents in eyes with and without flap subluxation was performed. No significant differences were found, although the results in eyes with flap subluxation were worse than those in eyes without flap subluxation. Additional complications were also higher in eyes with flap subluxation. CONCLUSION Flap subluxation is a serious but manageable complication of LASIK. If it is detected early, the visual prognosis is as good as that in eyes without flap subluxation.

Macula and retinal nerve fiber layer in migraine patients: analysis by spectral domain optic coherence tomography.

Abstract Aim: Investigating the retinal nerve fiber layer (RNFL), macular and ganglion cell complex thickness in eyes of migraine patients using optical coherence tomography. Methods: The study was designed as an observational cross-sectional study. 50 patients with migraine (30 patients with aura and 20 patients without aura) and 50 healthy volunteers were included. Optical coherence tomography was performed with Optovue technology. The fast RNFL thickness (3.4) scan, MM5, and GCC acquisition protocols were used. Results: There was no statistically significant difference in retinal thickness in any of the quadrants between the control group and the migraine patients (p > 0.05). The average RNFL thickness (110.50 vs 102.84 microns, p = 0.03) was significantly thinner in migrainers as compared to the control. The ANOVA did not reveal any significant difference between migrainers with aura, migrainers without aura, and the control group. The VAS (visual analogue scale) score of migraine patients was not statistically significantly correlated with any of the parameters, while the length of migraine history was negatively correlated with the average RNFL thickness (r = −0.32, p = 0.03). Conclusıon: The average RNFL thickness in the migraine patients was found to be thinner than that in the control group. In addition, we found a negative weak correlation between length of migraine history and the average RNFL thickness, supporting the possible association between these pathologies.

Oxidative Stress and Anti-oxidative Defence in Patients with Age-related Macular Degeneration

Abstract Purpose: To evaluate the oxidative stress status and anti-oxidative defence in patients with age-related macular degeneration (AMD). Methods: A total of 22 patients diagnosed with AMD and 23 age-matched healthy controls were included in the present study. Serum levels of total oxidant status (TOS), total antioxidant status (TAS), total thiol status (TTS) and paraoxonase 1 (PON1) activity were investigated from samples. Results: Significant increase in TOS levels were observed in sera of AMD patients (25.3 ± 12.8) compared to controls (15.0 ± 4.4). TTS (404.3 ± 55.3) and serum PON1 enzyme activities (163.0 ± 65.5) were significantly lower in AMD patients (594.0 ± 64.2) relative to control groups (252.8 ± 132.7). Conclusion: The results of the present study show that there is a significant increase in oxidative stress in AMD patients and significant decrease in antioxidant defence, in the total thiol level and in PON1 activity in AMD patients compared with controls. The increased oxidative stress and decreased antioxidant levels may have a synergistic role in AMD development.

Refractive Error May Influence Mesopic Pupil Size

Purpose: To identify factors which affect mesopic pupil diameter in refractive surgery patients. Setting: This retrospective study was performed at the 1st Ophthalmology Clinic in Ankara Ataturk Training and Research Hospital, Ankara, Turkey. Methods: Medical records of 412 refractive surgery candidates who applied between 2006 and 2008 were reviewed. Detailed ophthalmological examination data were obtained from medical records. Pupil size measurements were performed with a COAS Ocular Wavefront analyzer in mesopic conditions. Relationship between mesopic pupil diameter and age, sex, spherical refractive error (D), magnitude of astigmatism (D), type of astigmatism, spherical equivalent, and average keratometry were analyzed by means of univariate and multivariate regression analyses. Results: Mean mesopic pupil diameter was 6.19 ± 0.88 mm. Mean pupil diameter (mean ± standard deviation) was 5.70 ± 1.01 in hypermetropia, 6.04 ± 0.79 mm in mixed astigmatism, and 6.33 ± 0.82 mm in myopia. The difference in mean mesopic pupil diameters between myopes and hypermetropes was statistically significant (p = 0.001). However, differences with regard to mean pupil diameters between myopes and mixed astigmatism (p = 0.660) and between hypermetropes and mixed astigmatism (p = 0.109) were not significant. Mean pupil diameter was 6.00 ± 0.99 mm in against the rule astigmatism, 5.96 ± 0.84 mm in oblique astigmatism, and 6.27 ± 0.84 mm in with the rule astigmatism. Mean mesopic pupil diameter in with the rule astigmatism group was higher than oblique astigmatism group. Spherical refractive error (r = -0.213, p = 0.001), cylindrical refractive error (0.197, p = 0.001), and age (r = −0.341, p = 0.001) showed correlation with pupil diameter. Conclusions: This study showed that age and magnitude of both spherical and cylindrical refractive error are the most determinative factors on mesopic pupil size.

Thinning of Choroidal Thickness in Patients with Rheumatoid Arthritis Unrelated to Disease Activity

Abstract Purpose: To investigate subfoveal and perifoveal choroidal thickness (CT) in patients with rheumatoid arthritis (RA). Methods: A study group of 117 patients with RA and a control group of 46 age-matched healthy individuals were enrolled in the study. Subfoveal and perifoveal CTs were measured using enhanced depth imaging optical coherence tomography (EDI-OCT). Perifoveal CT was measured 1,500 µm nasally and 1,500 µm temporally apart from the foveal center. Relationship between the disease activity score 28 (DAS-28) and subfoveal CT was also evaluated. Results: The mean subfoveal CT values in the study and control groups were 226.90 ± 43.61 μm and 299.74 ± 48.06 μm, respectively, which made for a statistically significant difference (p < 0.001). Likewise, perifoveal CT values were significantly thinner in the study group when compared with control group. DAS-28 wasn’t correlated with subfoveal CT in the study group. Conclusions: CT was significantly thinner in patients with RA when compared with healthy controls.

Choroidal Thickness in Patients with Systemic Lupus Erythematosus Analyzed by Spectral-domain Optical Coherence Tomography

Abstract Purpose: The aim of this study is to investigate the effect of systemic lupus erythematosus (SLE) on choroidal thickness (CT) in the subfoveal and perifoveal area as measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in patients with SLE. Materials and methods: Fifty-eight patients with SLE (study group) and 58 healthy individuals (control group) were enrolled in the study. The subfoveal and perifoveal CT were measured by EDI-OCT. Results: The mean CT (μm) subfoveal, nasal, and temporal was 231.2 ± 57.6, 190.56 ± 30.64, and 222.65 ± 37.45 in the study group and 297.5 ± 45.1, 248.34 ± 39.67, and 286.54 ± 49.65 in the control group, respectively (p < 0.001, for all). Conclusion: The mean subfoveal, nasal, and temporal CT values were statistically significantly lower in patients with SLE when compared with healthy controls.

Effects of intracameral use of adrenalin solution with preservative on corneal endothelium

Objective: To evaluate the effects of injection of 1:100,000 dilution adrenalin with sodium bisulfite preservative on the corneal endothelium in phacoemulsification cataract surgery. Methods: This retrospective study comprised 70 patients with age-related cataracts who had undergone phacoemulsification cataract surgery with intraocular lens (IOL) implantation without any surgical complications. In the adrenalin group, patients with intraoperative intracameral adrenalin use were included. The intracameral adrenalin was composed of 1 mL of 1:100,000 dilution adrenalin with sodium bisulfite preservative. The control group included patients who underwent surgery without any intracameral adrenaline use. There were 36 patients in the adrenalin group and 34 patients in the control group. Corneal endothelial density, endothelial cell morphology, and endothelial cell area were measured via specular microscopy both preoperatively and 3 months after surgery. The 2 groups were compared with regard to changes in specular microscopy measurements. Results: The mean (± standard deviation) age was 66.51 ± 8.32 years in the adrenalin group and 67.58 ± 7.83 years in the control group. The difference in age between the 2 groups was not significant (p = .611). The preoperative mean corneal endothelial cell density was 2,270 ± 286 cells/mm2 in the adrenalin group and 2,226 ± 260 cells/mm2 in the control group, and the difference between the 2 groups was not statistically significant (p = .550). In the adrenalin group, the postoperative mean corneal endothelial cell density was 2,191 ± 268 cells/mm2. Although the postoperative mean cell density was lower than the preoperative mean cell density, the difference between the 2 measurements was not statistically significant (p = .117). In the control group, the postoperative mean corneal endothelial cell density was 2,169 ± 272 cells/mm2, and the difference between the preoperative and postoperative measurements was not statistically significant (p = .161). Comparisons of postoperative specular microscopy measurements between the adrenalin and control groups with regard to cell density, cell sizes, and cell shapes showed that there were no statistically significant differences in comparison of all parameters between the 2 groups. Conclusions: Intracameral injection of 1:100,000 dilution adrenalin with sodium bisulfite preservative is not toxic to corneal endothelium.

Suspected Bacterial Endophthalmitis Following Sustained-release Dexamethasone Intravitreal Implant: A Case Report

A 58-year-old man admitted to our opthalmology department with the complaint of branch retinal vein occlusion. He was treated with intravitreal Ozurdex in the right eye. Two days after the injection, the patient presented with ocular pain and the visual acuity was hand movement. A diagnosis of endophthalmitis was made. We performed emergent pars plana vitrectomy (PPV) and the implant was removed from the vitreous cavity using a retinal forceps. A combination of vancomycin 1.0 mg and amikacin 0.4 mg was injected intravitreally. However, because of the blurring in the vitreus one week after the procedure, phacoemulsification and a repeat PPV was performed. Five days after the last procedure the signs and symptoms of endophthalmitis were resolved. Our case demonstrated that endophthalmitis could develop after intravitreal implantation of Ozurdex. Surgical removal of the implant and immediate vitrectomy seems to be a useful treatment option in these cases.