Corneal innervation changes in Alzheimer's: implications for sensory dysfunction.

PURPOSE: To compare, between Alzheimer's disease (AD) patients and healthy individuals, corneal subbasal nerve plexus (CSNP) parameters and corneal sensitivities. METHODS: Twenty-two patients who were followed up with Alzheimer's disease (Alzheimer's group) and 18 age- and gender-matched healthy individuals (control group) were included in this cross-sectional study. CSNP parameters, including nerve fiber length (NFL), nerve fiber density (NFD), and nerve branch density (NBD), were evaluated using in vivo confocal microscopy. Corneal sensitivity was evaluated using a Cochet-Bonnet esthesiometer. The results were compared between the two groups. RESULTS: In the Alzheimer's group, NFL was 12.2 (2.4) mm/mm2, NFD was 12.5 [3.1] fibers/mm2, and NBD was 29.7 [9.37] branches/mm2. In the control group, NFL was 16.5 (2.0) mm/mm2, NFD was 25.0 [3.13] fibers/mm2, and NBD was 37.5 [10.9] branches/mm2. All three parameters were significantly lower in the Alzheimer's group compared to the control group (p < 0.001, p < 0.001, and p = 0.001, respectively). Similarly, corneal sensitivity was significantly lower in the Alzheimer's group (55.0 [5.0] mm) compared to the control group (60.0 [5.0] mm) (p < 0.001). CONCLUSION: We determined that, in AD, corneal sensitivity decreases significantly, in parallel with the decrease in corneal nerves. Changes in the corneal nerve plexus and a decrease in corneal sensitivity may be used in the early diagnosis and follow-up of AD. In addition, ocular surface problems secondary to these changes should also be kept in mind.

Ocular-symptoms-related Google Search Trends during the COVID-19 Pandemic in Europe.

PURPOSE: To investigate the correlation between the daily relative search volume (RSV) of keywords related to coronavirus and ocular symptoms, and the numbers of the daily coronavirus disease 2019 (COVID-19) new cases and new deaths in Europe using Google Trends (GT). METHODS: The RSVs of the selected keywords related to coronavirus and ocular symptoms between 24 January and 1 June 2020 in the United Kingdom, Spain, Italy, Germany and Turkey were accessed from GT. The numbers of daily COVID-19 new cases and new deaths in the same time interval in the aforementioned countries were compared with the RSVs of the keywords and terms. RESULTS: The United Kingdom, Spain, Italy, Germany, and Turkey were the most affected countries from the COVID-19 pandemic in Europe. In these countries, statistically significant and strong correlations were found between the daily RSVs of most keywords related to coronavirus and ocular symptoms, and the daily numbers of COVID-19 new cases and new deaths ranging from 0.175 to 0.807. CONCLUSIONS: Ocular symptoms are not the frequent signs of COVID-19, but the ocular surface is a possible route for the transmission of COVID-19. The preliminary outcomes of this study demonstrated that there are significant correlations with the ocular symptoms and COVID-19. The news about the relation of eye and COVID-19 in the mass media may have influenced the Google internet search activity of the public for ocular symptoms.

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.

Traumatic luxation of the globe: A 6-year follow-up.

A 25-year-old man was involved in a motor vehicle accident. The left globe was luxated out of orbit with total optic nerve avulsion. The globe was intact without any penetration and put back into the orbit. Although the patient has no light perception, he is grateful for satisfactory cosmetic results with 6-year follow-up.

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

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.

GAPO syndrome: four new patients with congenital glaucoma and myelinated retinal nerve fiber layer.

This article reports on the ophthalmological features of four Turkish children with GAPO syndrome, a very rare autosomal recessive condition characterized by growth retardation (G), alopecia (A), pseudoanodontia (P) (failure of tooth eruption), and optic atrophy (O). The children were from two unrelated families born to consanguineous parents. They had the characteristic facial appearance of alopecia, rarefaction of eyebrows and eyelashes, frontal bossing, high forehead, midfacial hypoplasia, hypertelorism, and thickened eyelids and lips. Two children had severe end-stage glaucoma in both eyes and unilateral corneal opacity, whereas other two children had myelinated retinal nerve fiber layer; one with bilateral optic atrophy and the other one with persistent pupillary membrane in the left eye.

Dry eye disease and ocular surface characteristics in patients with keratoconus.

PURPOSE: The purpose of this study is to investigate the ocular surface alterations in patients with mild or severe keratoconus (KC). METHODS: A total of 80 participants were included in the study. The corneal topography was performed on each participant using Pentacam and the grouping was done accordingly. The patients with Kmax ≥52.0 D (severe KC) were considered Group 1 (n = 28), the patients with Kmax ≥47.2 and <52.0 D (mild KC) were considered Group 2 (n = 30). Healthy control participants with Kmax <47.2 D were considered Group 3 (n = 22). Tear breakup time (TBUT), Schirmer-I test, ocular surface disease index (OSDI) questionnaire, and conjunctival impression cytology (CIC) were evaluated among the groups. RESULTS: The mean values of TBUT and Schirmer-I test were significantly lower (P = 0.012, P = 0.012) and the mean scores of OSDI and CIC were significantly higher (P = 0.006, P < 0.001) in Group 1 and Group 2 than in Group 3. The mean values of TBUT and Schirmer-I test were lower and the mean scores of OSDI and CIC were higher in Group 1 than in Group 2 but the differences were insignificant (P > 0.05 for all). CONCLUSION: These results indicated that the tests associated with dry eye disease are correlated with KC. Tear film alterations and goblet cell loss are higher in severe KC.

Evaluation of the Systemic Inflammation in Patients with Pterygium: Monocyte-to- High-Density Lipoprotein Cholesterol Ratio and Hematologic Indexes of Inflammation.

PURPOSE: The purpose of this study is to evaluate systemic inflammation in patients with pterygium using the monocyte-to-high-density lipoprotein cholesterol ratio (MHR) and hematologic indexes of inflammation. METHODS: Thirty-one patients with primary pterygium and 31 age-and sex-matched healthy participants were enrolled in this retrospective study. The MHR, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio, platelet-to-lymphocyte ratio, eosinophil-to-lymphocyte ratio, monocyte-to-eosinophil ratio, mean platelet volume-to-platelet count ratio, platelet distribution width, and red cell distribution width were compared between the two groups. RESULTS: There was not a statistically significant difference in terms of the MHR between the pterygium group and the control group (P = 0.693). The NLR was higher in the pterygium group than in the control group (P = 0.028). In the other hematologic indexes, there were no statistically significant differences between the two groups (P > 0.05 for all). CONCLUSION: The MHR is not associated with the presence of pterygium. An increased NLR in patients with pterygium may be an indicator of systemic inflammation.

The Causes and Frequency of Monocular and Binocular Blindness in Adults Applying to the Health Committee of a University Hospital in Central Anatolia

Objectives: The aim of this study was to investigate the frequency of blindness and the pathologies that cause blindness in the Konya province of Turkey. Materials and Methods: The records of individuals over 18 years of age who applied to the health committee of Meram School of Medicine Hospital between January 2015 and December 2018 were evaluated retrospectively. Results: After reviewing the records of 4,268 applicants, a total of 222 applicants were included in the study (159 patients with monocular blindness, 63 patients with binocular blindness). The most common causes of monocular blindness were optic atrophy (13%), amblyopia (11%), and phthisis bulbi (10%). The most common causes of binocular blindness were retinitis pigmentosa (28%), proliferative diabetic retinopathy (13%), and unoperated cataract (11%). The frequency of monocular blindness was 3.7% (95% confidence interval [CI]: 3.2-4.3%) and binocular blindness was 1.5% (95% CI: 1.1-1.9%) in the sample. The frequency of blindness increased with age, with a positive correlation between mean age and blindness (p=0.002). Monocular blind applicants had a significantly lower mean age than binocular blind applicants (48.8±13.3 vs. 55.0±13.1 years, p=0.002) and binocular blind women had a significantly higher mean age than binocular blind men (62.7±16.0 vs. 53.2±11.7 years, p=0.023). The prevalence of monocular and binocular blindness was significantly higher in men than women (p=0.032). Conclusion: The results of this study show that many of the pathologies that cause blindness are preventable or treatable, and that blindness is associated with age.

Effect of serum cytokines and VEGF levels on diabetic retinopathy and macular thickness.

PURPOSE: To investigate the role of serum inflammatory cytokines and vascular endothelial growth factor (VEGF) in diabetic retinopathy (DR) and evaluate their relationship with macular thickness measurements obtained with optical coherence tomography (OCT). METHODS: The study enrolled 28 healthy subjects (Group 1), 31 patients without DR (Group 2), 49 patients with nonproliferative DR (Group 3), and 46 patients with proliferative DR (Group 4). Macular profile was assessed with Stratus OCT-3 and the serum concentrations of VEGF and interleukin-1 alpha (IL-1 alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), macrophage inflammatory protein (MIP-1 alpha), monocyte chemoattractant protein (MCP-1), and epidermal growth factor (EGF) were measured using multiplex bead immunoassay. RESULTS: The median value of the visual acuity was 20/20 (Groups 1 and 2), and 20/100 (Group 3), and 20/125 (Group 4). The median value of central subfield macular thickness was estimated as 165.50 microm in Group 1, 202.5 microm in Group 2, 318 microm in Group 3, and 310 microm in Group 4. The median serum VEGF level, which was 98.20 pg/ml in Group 1, demonstrated a progressive rise to 125.37 pg/ml in Group 2, to 153.07 pg/ml in Group 3, and to 149.12 pg/ml in Group 4. Statistical significance was found between all groups (p<0.05) except between Groups 3 and 4 (p=0.87). The median levels of IL-1 alpha and IL-6 were zero in all groups. The median serum levels of IL-8, IL-10, MIP-1 alpha, and EGF revealed a wide range within each group but no statistical significance between the groups (p>0.05). The median serum levels of IL-8, IL-10, MIP-1 alpha, and EGF revealed a wide range within each group, however, no statistically significant relationship was found between the groups (p>0.05). The median values of the serum MCP-1 concentrations presented a statistically significant rise with the progression of DR (p=0.02). No correlation was found between macular thickness and serum cytokine and VEGF levels (p>0.05). CONCLUSIONS: Increased serum levels of VEGF and MCP-1 may act as a key regulator of DR and provide a potential tool for risk assessment in diabetic patients. Further studies that evaluate both vitreous and serum levels in various stages of DR are needed to provide a better understanding of the interaction between systemic and local inflammatory and angiogenic factors.

The Frequency and Causes of Blindness in a Rural Region of Central Anatolia of Turkey.

OBJECTIVE: This study aimed to evaluate the frequency and primary causes of blindness in adults aged 18 years and more in Sarikaya rural region of Yozgat, Turkey, to contribute to the epidemiologic information about blindness in our country. MATERIALS AND METHODS: Patients who were examined between October 2016 and March 2017 in Sarikaya State Hospital, Clinic of Ophthalmology, were prospectively investigated. Demographic and ophthalmic examination data, presented visual acuities (VA), primary causes of blindness, and monocular blindness were recorded. Blindness was defined as presented visual acuities (VA) definition of World Health Organization criteria. RESULTS: A total of 3423 participants, aged 18-96 years, were examined. Among them, 1887 participants (55%) were female and 1536 (45%) were male. The frequency of blindness was 1.5% (95% CI: 1.1%-2.0%); and cataract was the primary cause of blindness (42%). Age-related macular degeneration (21%) and uncorrected refractive error (13%) were the next main causes of blindness. The frequency of monocular blindness was 4% (95% CI: 3.8%-5.2%), and cataract (27%) followed by phthisis bulbi/evisceration (13%) and glaucoma (12%) were the leading causes of monocular blindness. CONCLUSION: In this rural region of Central Anatolia, the primary cause of blindness and monocular blindness was an unoperated cataract. The patterns of age-specific causes of blindness are variable, but most of them are avoidable or treatable. Thus, awareness should be increased in societies, and people should be prevented from blindness with health-care programs in rural regions of developing countries.

Improvement in rabbit corneal cell suspension viability after freezing with Gingko Biloba extract.

We investigated whether the addition of Gingko Biloba extract (EGb 761) to rabbit corneal epithelial medium before cell freezing improved cell viability after freezing then thawing. After removal of corneas, they were treated with enzymes and the corneal epithelium was prepared as a single cell suspension in freezing media with or without EGb 761. After freezing for two weeks then thawing, a higher cell viability was found in the cornea cell suspensions which had been frozen pretreated with EGb 761 in the media. The improvement with corneal cell viability with EGb 761 pretreatment is postulated to be based on the antioxidant capacity of the plant extract.

Improvement In Rabbit Corneal Cell Suspension Viability After Freezing With Gingko Biloba Extrakt.

We investigated whether the addition of Gingko Biloba extract (EGb 761) to rabbit corneal epithelial medium before cell freezing improved cell viability after freezing then thawing. After removal of corneas, they were treated with enzymes and the corneal epithelium was prepared as a single cell suspension in freezing media with or without EGb 761. After freezing for two weeks then thawing, a higher cell viability was found in the cornea cell suspensions which had been frozen pretreated with EGb 761 in the media. The improvement with corneal cell viability with EGb 761 pretreatment is postulated to be based on the antioxidant capacity of the plant extract.

Prospective, non-interventional, multicenter study of the intraocular pressure-lowering effects of prostaglandin analog/prostamide-containing therapies in previously treated patients with open-angle glaucoma or ocular hypertension.

OBJECTIVE: The objective of this study was to assess the intraocular pressure (IOP)-lowering efficacy, tolerability, safety, and usage patterns of prostaglandin analog/prostamide (PGA/P)-containing topical ocular hypotensives in ocular hypertension (OHT) and primary open-angle glaucoma in the Turkish clinical setting. METHODS: This non-interventional, multicenter study enrolled previously treated patients who failed to achieve target IOP (or experienced unacceptable adverse events [AEs]) and were prescribed a PGA/P-containing IOP-lowering agent. Treatment was initiated at baseline (V1), and patients returned at weeks 4-6 (V2) and 8-12 (V3). The primary efficacy measure was the change in IOP from baseline at V3 in each eye. The secondary measures were physician's assessment of IOP-lowering efficacy, patients (%) reaching target IOP determined at V1, hyperemia score, physician and patient assessment of study treatment tolerability at V3, and AE frequency/severity. A subgroup analysis of patients receiving the most common study treatment was conducted. All analyses were performed using the safety population (patients who received one or more doses and had any data available). RESULTS: Of 358 enrolled patients, 60.6% had primary open-angle glaucoma, 29.9% had secondary open-angle glaucoma (protocol amendment), and 13.1% had OHT; 13 patients had multiple diagnoses. At V3, the mean IOP change from baseline was ≥-4.2 mmHg (≥21.1%). IOP met or was lower than the target in 81.7% of patients, 95% exhibited none to mild conjunctival hyperemia (most common AE), and tolerability was rated good/very good by >91.1% of patients and physicians. The results were similar in patients who received the most common study treatment, bimatoprost 0.03%/timolol 0.5% (bim/tim; n=310). CONCLUSION: PGA/P-containing medications, including bim/tim, significantly reduced IOP in previously treated patients with open-angle glaucoma or OHT; most reached their target IOP or an IOP even lower than their target and reported good/very good tolerability. PGA/P-containing medications such as bim/tim should be considered as a safe, effective therapeutic option for Turkish patients who exhibit poor response, tolerance, or adherence to their previous therapy.

Six-month outcomes of corneal crosslinking with dextran-free isotonic riboflavin solution.

PURPOSE: To analyze the short-term clinical and topographic outcomes in patients with keratoconus after corneal collagen cross-linking treatment (CXL) with dextran-free isotonic riboflavin solution. METHODS: In this retrospective case series, 26 eyes from 26 patients with keratoconus were studied. The best corrected visual acuity (BCVA) and refractive and topographic findings were analyzed at a 6-month follow-up. RESULTS: The mean BCVA (Snellen lines) values before and 1, 3, and 6 months after CXL were 0.51 ± 0.2, 0.48 ± 0.2, 0.57 ± 0.2, and 0.64 ± 0.2, respectively, and the difference between the preoperative and 6-month values was statistically significant (p=0.006). The mean spherical equivalent refraction decreased from -5.6 ± 2.4 diopters (D) preoperatively to -5.0 ± 2.1 D, and mean simulated keratometry decreased from 48.5 ± 2.5 D to 47.8 ± 2.6 D at 6 months. (p=0.145 and p=0.001, respectively). In addition, the maximum keratometry decreased progressively and significantly from the preoperative value during follow-up (p=0.003). The central and minimal corneal thicknesses, including those of the epithelium, also decreased from 442.8 ± 25.6 µm and 430.5 ± 23.9 µm preoperatively to 420.7 ± 31.8 µm and 409.3 ± 28.7 µm at the most recent follow-up (p<0.001), respectively. No intraoperative or postoperative complications were observed. CONCLUSIONS: CXL with dextran-free isotonic riboflavin solution appears to be a safe treatment alternative for keratoconus and yields sustained short-term improvements in visual acuity, keratometric readings, and corneal thickness. However, long-term results are needed to confirm these outcomes.

Aqueous humor dynamics in monkeys after topical R-DOI.

PURPOSE: To determine the effects of R-DOI, a selective 5-HT2 agonist, on intraocular pressure (IOP) and aqueous humor dynamics in monkeys. METHODS: Normotensive cynomolgus monkeys (n = 8) were treated topically once daily with four 5-muL drops of 0.5% R-DOI in one eye, vehicle in the opposite eye. The 6-hour IOP response (Goldmann applanation tonometry) was determined before the drug application and on the third day of treatment. Aqueous humor formation, or flow (AHF, measured by fluorophotometry), was measured from hours 3 to 8 after the third dose. Beginning 3.5 hours after the fourth or fifth dose, AHF was measured by dilution of radio-iodinated monkey albumin perfused through the anterior chamber and flow to blood by accumulation of albumin in the general circulation. Uveoscleral outflow (Fu) was calculated. Flow to blood was determined at spontaneous and elevated pressures, allowing calculation of trabecular outflow facility. Total outflow facility was determined by two-level constant pressure perfusion from 3.5 to 5 hours and from 5.5 to 6.25 hours after R-DOI treatment. RESULTS: Reduction of IOP in treated eyes was compared to the opposite control eyes corrected for the 6-hour IOP baseline before the first dose. After the third dose of R-DOI, IOP was significantly (P < 0.01, n = 7) decreased by 1.4 to 4.7 mm Hg over the 6 hours. AHF (by fluorophotometry) increased by 13% (P < 0.05, n = 8) in treated compared with control eyes corrected for baseline. AHF (isotope dilution) increased by 30% (P < 0.01, n = 8), flow to blood decreased by 28% (n = 5), and Fu increased by 241% (P < 0.05, n = 5). Total and trabecular outflow facility were unchanged. CONCLUSIONS: R-DOI caused a small but significant increase in AHF and lowered IOP in normotensive monkeys primarily by increasing Fu.

The increase of intra-abdominal pressure can affect intraocular pressure.

OBJECTIVE: This study aims to explore the usage of intraocular pressure measurements as the early indicator of the increase in intra-abdominal pressure. METHODS: In this prospective study, 40 patients undergoing elective surgery were included. Patients were divided into four groups of 10 patients. The control group (Group C) was not subjected to laparoscopic intervention. Laparoscopic surgery was, respectively, performed with an intra-abdominal pressure of 9, 12, and 15 mmHg in Groups L (low), M (medium), and H (high pressure). Intraocular pressure was measured binocularly in each patient at three different times (before, during, and end of surgery) using a contact tonometer. RESULTS: Patients' gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) class, and operative times were not different among the groups. No complications occurred with either the surgery or measurement of intraocular pressure. Intubation was associated with a severe rise in IOP (P < 0.05). An increase in intraocular pressure was seen in groups M and H (P < 0.05). CONCLUSION: Intraocular pressure was increased in the groups with an intra-abdominal pressure of 12 mmHg or more. Measuring the intraocular pressure might be a useful method to estimate the intra-abdominal pressure. This trial is registered with NCT02319213.

Effect of low-dose latrunculin B on anterior segment physiologic features in the monkey eye.

OBJECTIVES: To determine if low doses of topical latrunculin B (LAT-B) will increase outflow facility and decrease intraocular pressure without damaging the cornea and if they will inhibit miotic and accommodative responses to pilocarpine in monkeys. METHODS: We measured intraocular pressure (Goldmann tonometry) before and after 1 and 9 doses of 0.005% and 0.01% topical LAT-B and vehicle given twice daily on successive weeks; outflow facility (perfusion) following 15 doses; central corneal thickness (ultrasonic pachymetry) before and after 1 and 9 doses of 0.01% LAT-B and vehicle; pupillary diameter (calipers); and accommodation (refractometry) before and after 1 dose of 0.005% and 0.02% LAT-B. RESULTS: Latrunculin-B dose-dependently decreased intraocular pressure, multiple doses more than a single dose. Maximal mean +/- SEM hypotension after 1 dose was 2.5 +/- 0.3 mm Hg (0.005% LAT-B; n = 8; P<.001) or 2.7 +/- 0.6 mm Hg (0.01% LAT-B; n = 8; P<.005); maximal mean +/- SEM hypotension after 9 doses was 3.2 +/- 0.5 mm Hg (0.005% LAT-B; n = 8; P<.001) or 4.4 +/- 0.6 mm Hg (0.01% LAT-B; n = 8; P<.001). Outflow facility was increased by mean +/- SEM 75% +/- 13% (n = 7; P<.005). Central corneal thickness was not changed after 1 or 9 doses of 0.01% LAT-B. Miotic and accommodative responses to intramuscular pilocarpine were dose-dependently inhibited. With 0.02% LAT-B, inhibition of miosis was substantial, whereas the inhibition of accommodation was only about 25%. With 0.005% LAT-B, the effects were trivial. CONCLUSIONS: In ocular normotensive monkeys, 0.005% and 0.01% LAT-B administered topically increases outflow facility and/or decreases intraocular pressure without corneal effects. Multiple doses reduce intraocular pressure more than a single dose. Latrunculin-B dose-dependently relaxes the iris sphincter and ciliary muscle, with some separation of miotic and accommodative effects. Clinical Relevance Multiple treatments with low topical doses of LAT-B may substantially reduce outflow resistance in eyes with glaucoma without adversely affecting the cornea.

Plasma homocysteine level and uveitis in Behçet's disease.

BACKGROUND: Behçet's disease is a chronic relapsing systemic vasculitis of unknown origin in which orogenital ulceration, skin lesions and uveitis are prominent features. Patients with BD have been recognized to be at greater risk for vascular diseases such as thrombosis and aneurysms. Uveitis in BD is usually accompanied by retinal vaso-occlusive disease. OBJECTIVE: To investigate the possible role of hyperhomocysteinemia as a prethrombotic disorder in the development of uveitis. METHODS: The study population consisted of 29 patients with BD (13 males and 16 females with a mean age of 32.3 years, range 21-52) and 24 healthy controls. All patients fulfilled the criteria of the International Study Group for BD. The patients were categorized as having active (n = 8) or inactive disease (n = 11) or only uveitis (n = 10). Plasma fasting homocysteine and C-reactive protein levels were studied in all patients and controls. The fasting homocysteine level was significantly higher in patients with only uveitis than in inactive patients and controls (P = 0.029 and P = 0.26 respectively). It was also higher in patients with active disease compared to healthy controls (P = 0.,001). However, no significant difference was found between homocysteine levels of patients with active or inactive disease (P = 0.69). CRP, as a marker of disease activity, was higher in active BD and in patients with only uveitis than in controls (P = 0.01 and P = 0.001 respectively). CONCLUSION: Homocysteine may play a role in ocular involvement of BD. Chronic inflammation can induce hyperhomocysteinemia, thereby leading to thrombosis in the retinal vascular bed in a way similar to that recently proposed for the pathogenesis of coronary artery disease.