Pupil barycenter configuration in patients with myopia and hyperopia.

PURPOSE: To compare the apparent chord mu between hyperopia and myopia cases and investigate the usefulness of iris barycenter configurations as an alternative for performing kappa angle distance calculations. METHODS: This prospective study evaluated 394 eyes of 197 patients classified into two groups according to their spherical equivalent values: the myopic (mean spherical equivalent refraction ≤ - 0.50 D) and the hyperopia group (mean spherical equivalent refraction ≥ + 0.50 D). The two groups were further subdivided according to severity (myopic group: mild, ≤ - 0.50 and ≤ - 3.00 D; moderate, < - 3.00 and ≤ - 6.00 D; severe, < - 6.00 D; hyperopic group: mild, ≥ + 0.50 and ≤ + 2.00 D; moderate, > + 2.00 and ≤ + 4.00 D; severe, > + 4.00 D). The pupil and iris barycenter distance measurements and other parameters were obtained through optical low-coherence reflectometry. RESULTS: Of the 197 patients, 109 (55.3%) were female and 88 (44.7%) were male individuals; their ages ranged from 7 to 60 years (mean, 35.16 ± 14.75 years). The average pupil barycenter distances were 0.38 ± 0.15 and 0.21 ± 0.11 mm in hyperopia and myopia patients, respectively (p < 0.01). Corneal and lens thickness measurements were higher in hyperopia patients (p < 0.01, p < 0.01, respectively), whereas anterior chamber depth and pupil diameter measurements were higher in myopia patients (p < 0.01, p < 0.01, respectively). No significant difference in astigmatism or white-to-white measurements was observed between hyperopia and myopia patients (p > 0.05). CONCLUSION: The measurements for the apparent chord mu of the pupil and iris barycenter origins were higher in hyperopic than in myopic cases.

Relationship between homocysteine levels, anterior chamber depth, and pseudoexfoliation glaucoma in patients with pseudoexfoliation.

PURPOSE: This study investigates the relationship between plasma homocysteine levels, anterior chamber depth (ACD), and pseudoexfoliation glaucoma (PEXG) in patients with pseudoexfoliation syndrome. METHODS: Sixty patients (F:M = 35:25) with pseudoexfoliation (PEX) were divided into two groups based on their plasma homocysteine levels; group 1 (< 20 µmol/L, normal) and group 2 (≥ 20 µmol/L, high). Intraocular pressure (IOP) and ACD values as well as plasma homocysteine levels were compared between the two groups. Moreover, the mean values for ACD and IOP were compared between patients stratified according to the reference upper limit for the homocysteine level (above and below 14 µmol/L), and the prevalence of high IOP was estimated. RESULTS: Groups 1 and 2 showed no statistically significant differences in the mean ACD (3.04 ± 0.28 vs. 3.07 ± 0.31 mm, respectively) and mean IOP (20.63 ± 10.22 vs. 21.67 ± 7.55 mmHg, respectively). Patients with PEX and homocysteine levels > 14 µmol/L had a significantly increased prevalence (P < 0.05) of high IOP (≥ 22 mmHg). CONCLUSIONS: Patients with PEX and high homocysteine levels have an increased prevalence of high IOP. No relationship exists between plasma homocysteine levels and ACD. Thus, PEXG should be suspected in patients with PEX and high plasma homocysteine levels. Plasma homocysteine levels could be helpful for the diagnosis of PEXG, although larger sample studies are required to confirm this finding.

MRI Results of Patients with Acute Isolyted Cranial Nerve Palsies.

AIM: To investigate the magnetic resonance imaging (MRI) results of patients complaining from diplopia with ocular nerve palsy. MATERIAL AND METHODS: A routine ophthalmic examination was performed, a neurological consultation was requested, and cranial MRI was performed for all patients. The image results were sorted into four groups: ischemic lesions, demyelinating disease lesions, tumors, and no lesions. White matter gliosis and cerebral infarcts were included in the ischemic lesion group. The medical histories of the patients were acquired from medical records. The chi-squared test was used to analyze the relationship between age and cranial MRI images and to analyze the relationship between the image and paresis type. The statistical significance threshold was set at p < 0.05, unless otherwise stated. RESULTS: Ischemic MRI images were the most common image type seen in our study. Third nerve paresis was significantly correlated with ischemic cerebral lesions observed by MRI (p=0.009). Furthermore, lesions were significantly correlated with patients aged above 50 years (p=0.004). There were no significant correlations between fourth or sixth nerve paresis and cranial ischemic images (p=0.680 and p=0.678, respectively). There were two instances of cerebral artery aneurysm, three instances of cerebral infarct, and one instance of intracranial mass, all in patients aged over 50 years. CONCLUSION: Although our patients had minimal or nonexistent neurological symptoms, some had serious cranial pathologies. These pathologies were commonly seen in patients aged over 50 years. We recommend performing MRI on all patients with binocular diplopia.

Corneal flap thickness with the Moria M2 single-use head 90 microkeratome in 72 consecutive LASIK procedures.

PURPOSE: This study aimed to evaluate the accuracy and consistency of corneal flap thickness in laser-assisted in situ keratomileusis (LASIK) with the Moria M2 single-use head 90 microkeratome. METHODS: The central corneal thickness of 72 (37 right, 35 left) eyes of 37 patients was measured by ultrasonic pachymetry preoperatively and intraoperatively after flap cut. The Moria M2 single-use head 90 microkeratome was used to create a superior hinged flap in all eyes. The right eyes were always operated on before the left eyes in each patient, using the same blade in all bilateral cases. All patients underwent LASIK for myopia and/or myopic astigmatism using VISX Star S4 platform. RESULTS: The mean preoperative spherical equivalent refraction was -3.55±2.30 D (range: -0.625 to -11.00 D), preoperative central corneal thickness by ultrasonic pachymetry was 541±26.82 µm (490-600 µm) and steepest K was 44.08±1.49 D (40-46.75 D) in all eyes. The mean flap thickness was 136.97±20.07 µm (106-192 µm), 131.2±19.5 µm (91-192 µm), and 134.16±19.85 µm (91-192 µm) in the right, left, and both eyes, respectively. A positive significant relationship was found between flap thickness and preoperative ultrasonic pachymetry thickness. No significant relationship was found between flap thickness and the age, preoperative spherical equivalent, and preoperative steepest K. The difference between the first and second eyes was not significant. There were no major intraoperative and postoperative complications in all eyes. CONCLUSION: The Moria M2 single-use head 90 microkeratome cut relatively thicker flaps than were intended. The flap thickness range was quite wide. This was a disadvantage for the accuracy and consistency of corneal flap thickness.

Performance of the SRK/T formula using A-Scan ultrasound biometry after phacoemulsification in eyes with short and long axial lengths.

BACKGROUND: The SRK/T formula is one of the third generation IOL calculation formulas. The purpose of this study was to evaluate the performance of the SRK/T formula in predicting a target refraction ±1.0D in short and long eyes using ultrasound biometry after phacoemulsification. METHODS: The present study was a retrospective analysis, which included 38 eyes with an AL < 22.0 mm (short AL), and 62 eyes ≥24.6 mm (long AL) that underwent uncomplicated phacoemulsification. Preoperative AL was measured by ultrasound biometry and SRK/T formula was used for IOL calculation. Three different IOLs were implanted in the capsular bag. The prediction error was defined as the difference between the achieved postoperative refraction, and attempted predicted target refraction. Statistical analysis was performed with SPSS V21. RESULTS: In short ALs, the mean age was 65.13 ± 9.49 year, the mean AL was 21.55 ± 0.45 mm, the mean K1 and K2 were 45.76 ± 1.77D and 46.09 ± 1.61D, the mean IOL power was 23.96 ± 1.92D, the mean attempted (predicted) value was 0.07 ± 0.26D, the mean achieved value was 0.07 ± 0.63 D, the mean PE was 0.01 ± 0.60D, and the MAE was 0.51 ± 0.31D. A significant positive relationship with AL and K1, K2, IOL power and a strong negative relationship with PE and achieved postoperative was found. In long ALs, the mean age was 64.05 ± 7.31 year, the mean AL was 25.77 ± 1.64 mm, the mean K1 and K2 were 42.20 ± 1.57D and 42.17 ± 1.68D, the mean IOL power was 15.79 ± 5.17D, the mean attempted value was -0.434 ± 0.315D, the mean achieved value was -0.42 ± 0.96D, the mean PE was -0.004 ± 0.93D, the MAE was 0.68 ± 0.62D. A significant positive relationship with AL and K1, K2 and a significant positive relationship with PE and achieved value, otherwise a negative relationship with AL and IOL power was found. There was a little tendency towards hyperopic for short ALs and myopic for long ALs. The majority of eyes (94.74 %) for short ALs and (70.97 %) for long ALs were within ±1 D of the predicted refractive error. No significant relationship with PE and IOL types, AL, K1, K2, IOL power, and attempted value, besides with MAE and AL, K1, K2, age, attempted, achieved value were found in both groups. CONCLUSION: The SRK/T formula performs well and shows good predictability in eyes with short and long axial lengths.

Effects of dorzolamide/timolol fixed combination on retrobulbar hemodynamics in pseudoexfoliative glaucoma.

In our study we aimed to evaluate the short-term effects of dorzolamide/timolol on ocular perfusion pressure and retrobulbar blood flow in patients with pseudoexfoliative glaucoma (PXG). This prospective observational cross-sectional study enrolled 22 eyes of 22 newly-diagnosed patients with PXG in a single center. All of the patients received a fixed combination of dorzolamide/timolol. Besides routine ophthalmologic examination, the retrobulbar hemodynamic parameters in the ophthalmic artery, central retinal artery, and short posterior ciliary arteries were measured in all participants at baseline and the 3(rd) month using color Doppler imaging. The mean intraocular pressure (IOP) was 22.3 ± 2.1 mmHg at baseline and reduced to 17.4 ± 2.3 mmHg at the 3(rd) month (p < 0.05). None of the retrobulbar parameters, except peak systolic velocity and resistive index in temporal short posterior ciliary arteries, changed significantly on therapy with dorzolamide/timolol fixed combination when the results were analyzed at Month 3. The drug significantly decreased the peak systolic velocity (p = 0.044) and reduced the resistive index in 0.04 units, 95% confidence interval 0.03-0.05, (p < 0.001) in the temporal short posterior ciliary arteries. This study reports that the retrobulbar hemodynamics might be affected less than expected by dorzolamide/timolol fixed combination in patients with PXG although the reduction of IOP was statistically significant.

Evaluation of bacterial contamination rate of the anterior chamber during phacoemulsification surgery using an automated microbial detection system.

AIM: To assess the incidence of anterior chamber bacterial contamination during phacoemulsification surgery using an automated microbial detection system (BacT/Alert). METHODS: Sixty-nine eyes of 60 patients who had uneventful phacoemulsification surgery, enrolled in this prospective study. No prophylactic topical or systemic antibiotics were used before surgery. After antisepsis with povidone-iodine, two intraoperative anterior chamber aqueous samples were obtained, the first whilst entering anterior chamber, and the second at the end of surgery. BacT/Alert culture system was used to detect bacterial contamination in the aqueous samples. RESULTS: Neither aqueous samples obtained at the beginning nor conclusion of the surgery was positive for microorganisms on BacT/Alert culture system. The rate of bacterial contamination during surgery was 0%. None of the eyes developed acute-onset endophthalmitis after surgery. CONCLUSION: In this study, no bacterial contamination of anterior chamber was observed during cataract surgery. This result shows that meticulous surgical preparation and technique can prevent anterior chamber contamination during phacoemulsification cataract surgery.

Late onset diffuse lamellar keratitis as a result of the toxic effect of Ecballium elaterium herb.

PURPOSE: To report a case of late onset diffuse lamellar keratitis (DLK) 11 months after LASIK due to Ecballium elaterium exposure. METHODS: A 25-year-old man underwent bilateral LASIK. No complications were observed during the early postoperative period. RESULTS: Eleven months after LASIK surgery, grade II DLK was diagnosed after an Ecballium elaterium herb seed burst and splashed into the patient's left eye. Topical steroid treatment was administered and DLK healed in 2 weeks without complication. CONCLUSIONS: Although DLK typically develops in the early postoperative period, it could occur months after surgery. Treatment should begin as soon as DLK is diagnosed.