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Intraoperative corneal thickness monitoring during corneal collagen cross-linking with isotonic riboflavin solution with and without dextran.

Purpose: The aim of this study was to analyze and compare corneal thickness changes during corneal collagen cross-linking procedures performed with isoosmolar riboflavin solution with 20% dextran and without dextran in corneal ectatic diseases. Methods: The patients in this study were analyzed in 2 groups: group 1 receiving riboflavin solution containing 20% dextran and group 2 receiving dextran-free riboflavin solution. Corneal thickness measurements were obtained with ultrasonic pachymetry at 6 different time points: preoperatively and at 0, 15, 30, 45, and 60 minutes after epithelial removal and initiation of ultraviolet A irradiation. Results: Twenty-seven eyes of 27 patients with progressive keratoconus were included in the study. In group 1 (n = 13), the mean preoperative thinnest pachymetric readings were 469.3 ± 8.5 &mgr;m, which decreased to 423.8 ± 8.9 &mgr;m after deepithelization and further decreased to 385.9 ± 10.9 &mgr;m at 15 minutes. The corneal thickness assumed a steady course at the 30-, 45-, and 60-minute measurements (378.9 ± 9.8 &mgr;m, 384.5 ± 10.5 &mgr;m, and 396.7 ± 9.4 &mgr;m, respectively). The initial change was statistically significant (P < 0.01). In group 2 (n = 14), the corneal thickness decreased from 459.4 ± 3.8 &mgr;m to 414.7 ± 2.6 &mgr;m with deepithelization, after which it increased steadily with the initiation of the dextran-free riboflavin solution. The final measurement in group 2 was 474.1 ± 9.4 &mgr;m; the increase at each time point was statistically significant when compared with the previous measurement (P < 0.01). Conclusions: Using isoosmolar riboflavin solution without dextran causes a steady increase in the corneal thickness during the cross-linking procedure, as opposed to riboflavin with dextran. This result might be beneficial in broadening the spectrum of cross-linking indications in patients with thin corneas.

Characteristics of the cornea in patients with pseudoexfoliation syndrome

PURPOSE To quantify the morphological alterations in corneal nerve fibers and cells in patients with pseudoexfoliation syndrome (PEX) and their relationship with the presence of hyperreflective endothelial deposits observed using in vivo confocal microscopy. METHODS One eye each of 37 patients with PEX and 20 age-matched healthy control subjects was evaluated by in vivo corneal confocal microscopy. Patients with PEX were further classified into two groups: those with and without hyperreflective endothelial deposits. We evaluated the densities of basal epithelial cells, anterior and posterior stromal keratocytes, and endothelial cells and structure of sub-basal nerve fibers. RESULTS The mean anterior and posterior stromal keratocyte and endothelial cell densities and corneal sub-basal nerve plexus variables were significantly lower in patients with PEX compared with those in healthy control subjects. The mean basal epithelial cell density did not significantly differ. CONCLUSION Eyes with PEX presented decreased corneal sub-basal nerve plexus variables and cell densities in all corneas, except for the mean basal epithelial cell density. Further, a trend of lower corneal sub-basal nerve plexus measurements in patients with hyperreflective endothelial deposits compared with those without endothelial deposits was observed.

The Effect of Dehydration and Fasting on Corneal Biomechanical Properties and Intraocular Pressure.

Purpose: To evaluate the changes in corneal biomechanical properties and intraocular pressure (IOP) during fasting period in healthy subjects. Methods: Seventy-two eyes of 72 fasting subjects (study group), and 62 eyes of 62 nonfasting subjects (control group) were enrolled in this prospective study undertaken at a single university hospital. All subjects underwent complete ophthalmologic examination including ocular biomechanical evaluation with ocular response analyzer. Ocular response analyzer measurement was performed on the right eyes of the subjects between 5.00 and 6.00 PM after approximately 14 hr of fasting for the study group and after a nonfasting period for the control group. The corneal hysteresis, corneal resistance factor, mean corneal compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg) values were measured with a patented dynamic bidirectional applanation process. Results: Goldmann-correlated IOP and IOPcc measurements in the study group and the control group were found as 13.8±2.8 mm Hg, 14.6±2.6 mm Hg and 16.3±2.2 mm Hg, 15.7±2.4 mm Hg, respectively. There was statistically significant difference within the two groups in IOPg and IOPcc (P<0.001). In addition, corneal hysteresis and corneal resistance factor significantly decreased in study group compared with control group (P<0.001, P=0.012, respectively). Conclusion: Prolonged fasting causes a significant decrease in IOPg, IOPcc, corneal hysteresis, and corneal resistance factor in healthy subjects, altering the biomechanical properties of the cornea.

Intraocular lens explantation or exchange: indications, postoperative interventions, and outcomes

PURPOSE To analyze the indications for explantation or exchange of intraocular lenses (IOLs), which were originally implanted for the correction of aphakia during cataract extraction. METHODS All cases that involved intraocular lens explantation or exchange in one institution between January 2008 and December 2014 were analyzed retrospectively. RESULTS In total, 93 eyes of 93 patients were analyzed. The median time interval between implantation and explantation of the anterior chamber intraocular lenses (AC IOL) and posterior chamber intraocular lenses (PC IOL) was 83.40 ± 83.14 months (range: 1-276 months) and 55.14 ± 39.25 months (range: 1-168 months), respectively. Pseudophakic bullous keratopathy (17 eyes, 38.6%) and persistent iritis (12 eyes, 27.8%) in the AC IOL group and dislocation or decentration (30 eyes, 61.2%) and incorrect IOL power (nine eyes, 18.4%) in the PC IOL group were the most common indications for explantation of IOLs. The mean logMAR best corrected visual acuity (BCVA) improved significantly from 1.30 preoperatively to 0.62 postoperatively in the PC IOL group (p<0.001) but did not improve significantly in the AC IOL group (p=0.186). CONCLUSIONS The primary indication for IOL explantation or exchange was pseudophakic bullous keratopathy in the AC IOL group and was dislocation or decentration in the PC IOL group. PC IOL explantation or exchange is safe and improves visual acuity.

Conjunctival Impression Cytology and Dry Eye in Patients With Ulcerative Colitis: A Pilot Study.

Purpose: The aim of this study was to compare signs of dry eye between ulcerative colitis (UC) patients and healthy subjects. Methods: Fifteen patients with UC (group 1) and 15 healthy subjects (group 2) were enrolled in this study. Tear volume measurement, Schirmer-I test with no anesthetic, tear break-up time, and conjunctival impression cytology (CIC) were evaluated in both groups. Results: Patients with UC showed lower tear volumes when compared with healthy subjects (P<0.05). There was a statistically significant difference in distribution of CIC grades between groups 1 and 2 (P<0.05). Tear break-up time and Schirmer-I measurements were significantly lower in group 1 compared with group 2 (P<0.05). Conclusions: The results of this study indicate that UC is associated with demonstrable disturbances in tear function and conjunctival cytology.

Effect of mydriasis induced by topical 0.5% tropicamide instillation on the corneal biomechanical properties in healthy individuals measured by ocular response analyzer

Abstract Purpose: This observational study aims to investigate the effects of tropicamide (0.5%) on corneal biomechanical properties, with the ocular response analyzer (ORA), in healthy individuals. Methods: Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) measurements of 38 (21 female and 17 male) healthy individuals, before and after 30 min of 0.5% tropicamide instillation, were performed by using the ORA. Results: The mean CH, CRF, IOPg and IOPcc measurements of the eyes were 10.2 ± 1.9 mmHg, 10.3 ± 2.1 mmHg, 15.7 ± 3.4 mmHg, 16.4 ± 3.3 mmHg pre-tropicamide, and 10.4 ± 1.7 mmHg, 10.3 ± 2.1 mmHg, 15.3 ± 3.4 mmHg, 15.8 ± 2.7 mmHg post-tropicamide, respectively. The differences between the pre- and post-tropicamide measurements of the eyes were insignificant (p = 0.184, p = 0.659, p = 0.294, p = 0.150, respectively; paired t-test). Conclusions: A tropicamide instillation does not lead to significant changes in the corneal biomechanical properties. Therefore, it can be used safely in disease, i.e. in the diagnosis and follow-up ORA as it does not cause any change.

Influence of cyclopentolate hydrochloride on corneal biomechanical properties in healthy individuals.

Objective: This observational study aims to investigate the effects of cyclopentolate hydrochloride (1%) on corneal biomechanical properties, with the ocular response analyzer (ORA), in healthy individuals. Methods: Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) measurements of 36 (15 female and 21 male) healthy individuals, before and after 45 min of 1% cyclopentolate hydrochloride instillation, were performed by the ORA. Results: The mean CH and IOPcc measurements of the eyes were 10.63±1.17 mm Hg and 15.15±2.69 mm Hg, precycloplegia, and 11.09±1.32 mm Hg and 14.16±2.77 mm Hg, postcycloplegia, respectively. The differences between the precycloplegia and postcycloplegia in both measurements were statistically significant (P=0.031, P=0.016, respectively; paired t test). The mean CRF and mean IOPg measurements of the eyes were 10.40±1.16 mm Hg and 14.83±2.56 mm Hg, precycloplegia, and 10.61±1.33 mm Hg and 14.25±2.65 mm Hg, postcycloplegia, respectively. The differences between the precycloplegia and postcycloplegia measurements of the eyes were insignificant (P=0.264 and P=0.100, respectively; paired t test). Conclusions: A 1% cyclopentolate hydrochloride instillation leads to significant changes in the CH values and IOPcc measurements. This should be taken into account during the evaluation of refractive surgery candidates and in clinical conditions where ORA measurements are considered in the diagnosis and follow-up.

Behcet's disease presenting with cerebral vasculitis: a case report.

IntroductionBehcets disease encompasses a group of multisystemic complications secondary to occlusive vasculitis. It presents usually with oral or genital ulcers however, other system involvements may be the first sign as well.Case presentationA 26-years-old man admitted to our clinic for his decreased visual acuity. Ophthalmologic examination revealed bilateral vitritis and optic disc swelling. However, the meticulously taken history included other complains like headache and oral ulcers. Further investigation with cranial MRI demonstrated cerebral vasculitis secondary to Behcets disease.ConclusionBehcets disease may be easy to diagnose when it presents with oral and genital ulcers or panuveitis, however presentation with optic disc swelling may warrant a thorough investigation.

The Association of Cataract and Lens Epithelial Cell Apoptosis in Patients with Pseudoexfoliation Syndrome

ABSTRACT Purpose: The aim of this study was to measure the density of apoptotic lens epithelial cells (LECs) and to determine its association with cataract formation in eyes with pseudoexfoliation syndrome (PEX). Materials and Methods: Twenty-one eyes of 21 patients diagnosed with PEX without glaucoma (Group 1) and 22 eyes of 22 subjects without PEX (Group 2) were enrolled in this study. During cataract surgery, anterior capsule samples were obtained by the 5.5 mm continuous curvilinear capsulorhexis method. Apoptosis was determined with a TUNEL kit (Boster, Wuhan, China) according to the manufacturer’s protocol. Four fields in each pathology preparation were chosen randomly under a microscope, and 100 cells were counted in each field to calculate the apoptosis rates. Results: Forty-three eyes of 43 subjects were enrolled in this study. There were no significant differences in age or sex between the two studied groups (p > 0.05). Under a microscope, the LECs were stained light blue and their nuclei were oval shaped. Positive stained cells were found occasionally in Group 2, while a significant amount of black-brown positively stained LECs with condensed nuclei was found in Group 1. The apoptosis rates were 35.2 ± 2.1% and 14.1 ± 1% in Groups 1 and 2, respectively. The proportion of positively stained LECs was higher in Group 1 (p < 0.001). Conclusion: Our study suggests that apoptosis in LECs is the pathophysiological mechanism for the higher rate of cataracts in PEX patients, in addition to the ocular ischemia hypothesis.

Unilateral Recurrent Anterior Uveitis as the Presenting Sign of Bladder Carcinoma.

A 79-year-old male patient was followed for unilateral uveitis with 3 attacks in 10 months, despite initial improvement with steroid therapy. The patient had visual acuity (VA) of counting fingers in right eye, hypopyon and vitritis with no chorioretinal lesions. The left eye was normal. The patient was evaluated for intraocular foreign body, intraocular lymphoma and associated systemic disease and malignancy. Computed tomography of the abdomen showed a mass in the bladder. Biopsy confirmed bladder carcinoma. After resection of the mass, intraocular inflammation improved completely and no attack was noted in the follow-up. In his last examination, two years after the operation, VA was light perception; seclusio pupilla and mature cataracts were seen on biomicroscopy. There was no sign of vitritis on ocular ultrasonography. Evidence is discussed that suggests a link and potential etiology between refractory uveitis with hypopyon and bladder carcinoma. This is the first case of unilateral recurrent uveitis with hypopyon as the initial presenting sign of bladder carcinoma.