Effect of light intensity on the tear production, central corneal thickness, and intraocular pressure in broiler chickens.

OBJECTIVE: The objective of the present study was to examine the effect of different light intensities on tear production, corneal thickness, and intraocular pressure in broilers. ANIMALS STUDIED: Both eyes of 72 male broilers were evaluated in this study. MATERIALS AND METHODS: Broilers were divided into the following three groups: low light intensity (n = 24, 5 lux), moderate light intensity (n = 24, 20 lux), and high light intensity (n = 24, 80 lux). The eyes of all birds (n = 72) underwent a complete ophthalmic examination, which included the Schirmer tear test (STT-I), intraocular pressure (IOP), and the central cornea thickness measurement (CCT). The effect of light intensity on the Schirmer test, intraocular pressure, and central corneal thickness values was examined at eye and animal level (right and left eyes separately and cumulatively/no distinguishing left or right) by using one-way ANOVA. RESULTS: At the animal level, without discrimination of left and right eye measurements, statistically significant differences were found between 5-20 and 20-80 lux groups on IOP measurements (p < .05). The difference in CCT measurements between the 5 and 20 lux groups was statistically significant (p < .05), and the corneal thickness of the 5 lux group animals was found to be statistically significant and higher than the 20 lux group (p < .05). CONCLUSIONS: In conclusion, light intensity has an influence on eye health in broilers. Present results may attribute to the future studies as a reference value for broilers raised under different light intensities.

Comparison of Intraocular Pressure Changes Due to Exposure to Mobile Phone Electromagnetics Radiations in Normal and Glaucoma Eye.

PURPOSE: The aim of this study is to investigate the effects of electromagnetic waves (EMWs) emitted by a mobile phone on the intraocular pressure (IOP) in the eyeball. METHODS: This quasi-experimental study was conducted on 166 eyes from 83 individuals in the 40-70 age range who referred to "Khatam-al-Anbia Hospital, Mashhad, Iran" in 2016. There were two groups of participants, and the first one consisted of 41 participants who had normal eyes, whereas the second one comprised 42 participants who suffered from open-angle glaucoma disease. The IOP in both groups was measured and recorded by a specialist before and after talking 5 min on the cellphone with the help of the Goldman method. Statistical analysis such as paired t-test and analysis of variance was performed and all tests are statistically significant at (P < 0.05). For this purpose, the SPSS software (version 16) was applied. RESULTS: IOP in the glaucoma eye (42 eyes) ipsilateral to mobile phone before and after the intervention was 18.64 ± 6.7 and 23.53 ± 6.3, respectively (P < 0.001). However, IOP in the control group (41 eyes) ipsilateral to mobile phone before and after the intervention was 12.95 ± 3.5 and 13.39 ± 2.8, respectively (P = 0.063). IOP change in the opposite glaucomatous eye to mobile phone in glaucoma group (39 eyes) and normal group (44 eyes) was not significantly different before and after the phone call (P = 0.065 and P = 0.85, respectively). CONCLUSION: We found that the acute effects of EMWs emitted from the mobile phones can significantly increase the IOP in glaucoma eye, while such changes were not observed in normal eyes.

Ocular hypertension suppresses homeostatic gene expression in optic nerve head microglia of DBA/2 J mice.

Glaucoma is the leading cause of irreversible vision loss. Ocular hypertension is a major risk factor for glaucoma and recent work has demonstrated critical early neuroinflammatory insults occur in the optic nerve head following ocular hypertension. Microglia and infiltrating monocytes are likely candidates to drive these neuroinflammatory insults. However, the exact molecular identity / transcriptomic profile of microglia following ocular hypertensive insults is unknown. To elucidate the molecular identity of microglia after long-term exposure to ocular hypertension, we used a mouse model of glaucoma (DBA/2 J). We performed RNA-sequencing of microglia mRNA from the optic nerve head at a time point following ocular hypertensive insults, but preceding detectable neurodegeneration (with microglia identified as being CD45lo/CD11b+/CD11c-). Furthermore, RNA-sequencing was performed on optic nerve head microglia from mice treated with radiation therapy, a potent therapy preventing neuroinflammatory insults. Transcriptomic profiling of optic nerve head microglia mRNA identifies metabolic priming with marked changes in mitochondrial gene expression, and changes to phagocytosis, inflammatory, and sensome pathways. The data predict that many functions of microglia that help maintain tissue homeostasis are affected. Comparative analysis of these data with data from previously published whole optic nerve head tissue or monocyte-only samples from DBA/2 J mice demonstrate that many of the neuroinflammatory signatures in these data sets arise from infiltrating monocytes and not reactive microglia. Finally, our data demonstrate that prophylactic radiation therapy of DBA/2 J mice potently abolishes these microglia metabolic transcriptomic changes at the same time points. Together, our data provide a unique resource for the community to help drive further hypothesis generation and testing in glaucoma.

Argon laser-assisted hypotony model in the rabbit.

To investigate whether ocular hypotony formation with 360 degrees endocyclophotocoagulation is possible. Twelve male New Zealand White rabbits were used. Entire ciliary body epithelium was destructed with green laser photocoagulation after pars plana lensectomy and anterior vitrectomy in six rabbits. Endocyclophotocoagulation was not performed to the remaining six rabbits (control group). Intraocular pressure (IOP) was measured preoperatively and followed up everyday in the first week and weekly until the end of month one. All of the rabbits were sacrificed and ciliary bodies were left for gross and light microscopic examination. Mean baseline IOPs were similar in laser and non-laser group (14.8 ± 1.4 (range 12.2-17.3) vs 14.4 ± 1.4 (range 12.2-15.9), p = 0.650). Mean IOP was 6.6 ± 0.45 mmHg (range 5.9-7.1) in the laser group and 11.5 ± 1.2 mmHg (range 10.2-13.4) in the non-laser group in postoperative day 1. IOP was below 4 mmHg in all eyes on the second day and after in laser group. In the macroscopic evaluation, the entire ciliary body had a white (loss of pigmentation) and atrophic appearance in all of the eyes in the laser-treated group compared to non-laser group. In the laser group, light microscopic examination demonstrated a severe 360 degrees disruption of ciliary processes. Ciliary processes were covered with fibrin exudation consisting of fibroblasts. There was a mild inflammation with disruption or atrophy of ciliary body epithelium with cystic vacuolar degeneration. Three hundred sixty degrees endocyclophotocoagulation yielded severe ciliary epithelium damage. IOP reduction started very early and continued in hypotonic levels during follow up period.

Cambios en la presión intraocular en pacientes con neuralgia trigeminal sometidos a radiofrecuencia del ganglio de Gasser / Changes in intraocular pressure in patients with trigeminal neuralgia subject to radio frequency of the Gasserian ganglion

Introducción: La neuralgia del trigémino es un cuadro caracterizado por ataques paroxísticos de dolor intenso, lancinante como descargas eléctricas, acompañado de sensación urente y de aparición periódica en la distribución de una o más ramas trigeminales. La relación anatómica entre el ganglio de Gasser y el seno cavernoso pudiera producir un incremento en la tensión intraocular después de la aplicación de la radiofrecuencia del ganglio trigeminal al modificar el drenaje venoso del ojo, situación que hasta el momento no se ha estudiado. El objetivo fue determinar si la aplicación de radiofrecuencia convencional en el ganglio de Gasser produce modificaciones en la tensión intraocular en pacientes con neuralgia trigeminal primaria de segunda y/o tercera rama. Material y métodos: Estudio longitudinal que incluyó a pacientes con diagnóstico de neuralgia del trigémino de segunda y/o tercera rama; en quirófano y bajo anestesia general, se les realizó procedimiento de radiofrecuencia en Ganglio de Gasser, con generador Neurotherm R 500, agujas de 100 mm de longitud y 22 G, con punta activa de 5 mm, estimulación sensitiva a 50 Hertz con 0,3-0,5 V aplicando 80 °C por 60 segundos en dos o tres fases. La presión intraocular se midió 24 horas previas al procedimiento, 24 horas posteriores al procedimiento y siete días después del mismo. El análisis de la presión intraocular, así como la escala EVA de dolor, se determinó mediante un análisis de ANOVA de medidas repetidas. Resultados: Se incluyeron 30 pacientes de los cuales 26 fueron mujeres, la edad promedio fue de 59,6 ± (DE 11,16). La tensión intraocular 24 h antes, un día después y una semana después de la realización de la radiofrecuencia del ganglio de Gasser no mostró modificaciones significativas con ANOVA para muestras repetidas (p = 0,916). Conclusiones: La tensión intraocular no se modificó a corto plazo después de realizar radiofrecuencia del ganglio de Gasser

Introduction: Trigeminal neuralgia is characterized by paroxysmal attacks of intense pain, lancinating as electric shocks, accompanied by burning sensation and periodic appearance in the distribution of one or more trigeminal branches. The anatomical relationship between the Gasser ganglion and the cavernous sinus could produce an increase in the intraocular tension after the application of the radiofrequency of the trigeminal ganglion when modifying the venous drainage of the eye, a situation that until now has not been studied. The objective was to determine if the application of conventional radiofrequency in the Gasser ganglion produces changes in the intraocular tension in patients with primary trigeminal neuralgia of second and / or third branch. Material and methods: Longitudinal study that included patients diagnosed with trigeminal neuralgia of second and / or third branch; In the operating room and under general anesthesia, radiofrequency procedure was performed in Gasser ganglion, with generator Neurotherm R 500, needles of 100 mm in length and 22 G, with active tip of 5 mm, sensory stimulation at 50 Hertz with 0.3 - 0.5 V applying 80º C for 60 seconds in 2 or 3 phases. Intraocular pressure was measured 24 hours before the procedure, 24 hours after the procedure and seven days after the procedure. The analysis of the intraocular pressure, as well as the EVA scale of pain was determined by an ANOVA analysis of repeated measures. Results: Thirty patients were included of which 26 were women, the average age was 59.6 ± (SD 11.16). Intraocular tension 24 h before, one day after and one week after performing radiofrequency of the Gasser ganglion, did not show significant changes with ANOVA for repeated samples (p 0.916). Conclusions: Intraocular tension was not modified in the short term after radiofrequency of the Gasser ganglion

Síndrome de la transiluminación iridiana aguda bilateral. A propósito de un caso clínico / Bilateral acute iris transillumination syndrome. A case report

OBJETIVO: Presentar el caso clínico de una paciente con el síndrome de la transiluminación iridiana aguda bilateral (BAIT). MÉTODOS: El síndrome de BAIT es una nueva entidad clínica caracterizada por una transiluminación iridiana, dispersión de pigmento en la cámara anterior y una pupila en midriasis media que no responde o es poco sensible a la luz debido a una parálisis del esfínter. Los pacientes con BAIT suelen presentar dolor ocular agudo, fotofobia y ojo rojo. DISCUSIÓN: Presentamos el caso clínico de una mujer de 53 años que, tras ser tratada de una infección del tracto respiratorio superior con moxifloxacino, desarrolló un síndrome de BAIT, diagnosticado en primera instancia de uveítis anterior aguda. CONCLUSIÓN: Este es, hasta donde se conoce, el primer caso reportado en Navarra, aunque es necesaria mayor casuística para establecer patrones claros acerca de esta enfermedad

OBJECTIVE: To present a case report of a patient with a bilateral acute iris transillumination syndrome (BAIT). METHODS: BAIT syndrome is a new clinical condition characterised by severe transillumination of the iris, acute onset of pigment dispersion in the anterior chamber, and a medial mydriatic pupil that is unresponsive or poorly responsive to light, due to a sphincter paralysis. Patients with BAIT generally present with acute ocular pain, photophobia, and red eyes. DISCUSSION: The case is presented of a 53 year-old woman, who, after being treated with moxifloxacin for an upper respiratory tract infection, developed a BAIT syndrome, which was initially diagnosed as acute anterior uveitis. CONCLUSION: As far as is known this is the first case reported in Navarra, but more case reports are needed to establish clear patterns about this condition

Antarctica eye study: a prospective study of the effects of overwintering on ocular parameters and visual function.

BACKGROUND: In 2013 five polar explorers attempted to complete the first Trans-Antarctic Winter Traverse (TAWT). This study presents the ophthalmological findings for this group, who overwintered in Antarctica as part of the White Mars Human Science Protocol. Antarctic crews are exposed to extreme cold, chronic hypoxia and altered day-night cycles. Previous studies of Antarctic explorers have focused on the prolonged effect of ultraviolet radiation including the development of ultraviolet keratitis and accelerated cataract formation. This is the first study of its kind to investigate the effect of overwintering in Antarctica on the human eye. METHODS: Pre and post-expedition clinical observations were made including visual acuity, contrast sensitivity, colour vision, auto-refraction, subjective refraction, retinal examination, retinal autofluoresence and retinal thickness, which were graded for comparison. During the expedition additional observations were made on a monthly basis including LogMAR visual acuity, autorefraction and intraocular pressure. RESULTS: No significant differences between pre and post-expedition observations were found, including visual acuity, contrast sensitivity, colour vision, refraction, visual fields, intraocular pressure and retinal examination. There was a small but statistically significant decrease in retinal thickness across all regions of the retina, except for the macular and fovea, in all explorers. Intra-expedition observations remained within normal limits. CONCLUSION: Reassuringly, the human eye remains largely unchanged by exposure to the extreme conditions encountered during the Antarctic winter, however, further research is needed to investigate changes in retinal thickness. This may have implications for scientists who spend prolonged periods of time in the polar regions, as well as those who have prolonged exposure to the extreme cold or chronic hypoxia in other settings.

Cyclodestructive procedures for non-refractory glaucoma.

BACKGROUND: Glaucoma is a leading cause of blindness worldwide. It results in a progressive loss of peripheral vision and, in late stages, loss of central vision leading to blindness. Early treatment of glaucoma aims to prevent or delay vision loss. Elevated intraocular pressure (IOP) is the main causal modifiable risk factor for glaucoma. Aqueous outflow obstruction is the main cause of IOP elevation, which can be mitigated either by increasing outflow or reducing aqueous humor production. Cyclodestructive procedures use various methods to target and destroy the ciliary body epithelium, the site of aqueous humor production, thereby lowering IOP. The most common approach is laser cyclophotocoagulation. OBJECTIVES: To assess the effectiveness and safety of cyclodestructive procedures for the management of non-refractory glaucoma (i.e. glaucoma in an eye that has not undergone incisional glaucoma surgery). We also aimed to compare the effect of different routes of administration, laser delivery instruments, and parameters of cyclophotocoagulation with respect to IOP control, visual acuity, pain control, and adverse events. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 8); Ovid MEDLINE; Embase.com; LILACS; the metaRegister of Controlled Trials (mRCT) and ClinicalTrials.gov. The date of the search was 7 August 2017. We also searched the reference lists of reports from included studies. SELECTION CRITERIA: We included randomized controlled trials of participants who had undergone cyclodestruction as a primary treatment for glaucoma. We included only head-to-head trials that had compared cyclophotocoagulation to other procedural interventions, or compared cyclophotocoagulation using different types of lasers, delivery methods, parameters, or a combination of these factors. DATA COLLECTION AND ANALYSIS: Two review authors independently screened search results, assessed risks of bias, extracted data, and graded the certainty of the evidence in accordance with Cochrane standards. MAIN RESULTS: We included one trial (92 eyes of 92 participants) that evaluated the efficacy of diode transscleral cyclophotocoagulation (TSCPC) as primary surgical therapy. We identified no other eligible ongoing or completed trial. The included trial compared low-energy versus high-energy TSCPC in eyes with primary open-angle glaucoma. The trial was conducted in Ghana and had a mean follow-up period of 13.2 months post-treatment. In this trial, low-energy TSCPC was defined as 45.0 J delivered, high-energy as 65.5 J delivered; it is worth noting that other trials have defined high- and low-energy TSCPC differently. We assessed this trial to have had low risk of selection bias and reporting bias, unclear risk of performance bias, and high risk of detection bias and attrition bias. Trial authors excluded 13 participants with missing follow-up data; the analyses therefore included 40 (85%) of 47 participants in the low-energy group and 39 (87%) of 45 participants in the high-energy group.Control of IOP, defined as a decrease in IOP by 20% from baseline value, was achieved in 47% of eyes, at similar rates in the low-energy group and the high-energy groups; the small study size creates uncertainty about the significance of the difference, if any, between energy settings (risk ratio (RR) 1.03, 95% confidence interval (CI) 0.64 to 1.65; 79 participants; low-certainty evidence). The difference in effect between energy settings based on mean decrease in IOP, if any exists, also was uncertain (mean difference (MD) -0.50 mmHg, 95% CI -5.79 to 4.79; 79 participants; low-certainty evidence).Decreased vision was defined as the proportion of participants with a decrease of 2 or more lines on the Snellen chart or one or more categories of visual acuity when unable to read the eye chart. Twenty-three percent of eyes had a decrease in vision. The size of any difference between the low-energy group and the high-energy group was uncertain (RR 1.22, 95% CI 0.54 to 2.76; 79 participants; low-certainty evidence). Data were not available for mean visual acuity and proportion of participants with vision change defined as greater than 1 line on the Snellen chart.The difference in the mean number of glaucoma medications used after cyclophotocoagulation was similar when comparing treatment groups (MD 0.10, 95% CI -0.43 to 0.63; 79 participants; moderate-certainty evidence). Twenty percent of eyes were retreated; the estimated effect of energy settings on the need for retreatment was inconclusive (RR 0.76, 95% CI 0.31 to 1.84; 79 participants; low-certainty evidence). No data for visual field, cost effectiveness, or quality-of-life outcomes were reported by the trial investigators.Adverse events were reported for the total study population, rather than by treatment group. The trial authors stated that most participants reported mild to moderate pain after the procedure, and many had transient conjunctival burns (percentages not reported). Severe iritis occurred in two eyes and hyphema occurred in three eyes. No instances of hypotony or phthisis bulbi were reported. The only adverse outcome that was reported by the treatment group was atonic pupil (RR 0.89 in the low-energy group, 95% CI 0.47 to 1.68; 92 participants; low-certainty evidence). AUTHORS' CONCLUSIONS: There is insufficient evidence to evaluate the relative effectiveness and safety of cyclodestructive procedures for the primary procedural management of non-refractory glaucoma. Results from the one included trial did not compare cyclophotocoagulation to other procedural interventions and yielded uncertainty about any difference in outcomes when comparing low-energy versus high-energy diode TSCPC. Overall, the effect of laser treatment on IOP control was modest and the number of eyes experiencing vision loss was limited. More research is needed specific to the management of non-refractory glaucoma.

The relationship of systemic markers of haemostasis with retinal blood vessel responses in cardiovascular disease and/or diabetes.

Background Hypercoagulability is a leading factor in diabetes and cardiovascular disease. Retinal vessel responses to flickering light are an important tool for assessing ocular function. We hypothesised a significant relationship between systemic markers of haemostasis and retinal vessel function. Methods Intra-ocular pressure and retinal microcirculation function were measured in 116 patients with diabetes and/or cardiovascular disease using unstimulated and stimulated arterial and venous retinal vessel responses to flickering light. Haemostasis was evaluated by platelet microparticles, soluble P selectin, and five functional markers of fibrin clot formation and lysis, hyperglycaemia by HbA1c. Results Intra-ocular pressure was linked to the rates of clot formation (p = 0.006) and clot dissolution (p = 0.013) whilst central retinal vein equivalent was linked to HbA1c (p = 0.017). In the first of three flickering light cycles only, arterial baseline diameter fluctuation was linked to the lag time to clot formation (p = 0.017), whilst maximum venous dilatation was linked to HbA1c (p = 0.001) and clot density (p = 0.011). HbA1c was linked to venous dilatation amplitude (p = 0.003). There were no significant links between any ocular index and any platelet index. Conclusions In addition to glycaemia, several haemostasis measures, but no measures of platelet activity, are linked to ocular and retinal blood vessel indices in patients with diabetes and/or cardiovascular disease. These associations may have pathophysiological significance.

Impact of laser pulse duration on the reduction of intraocular pressure during selective laser trabeculoplasty.

PURPOSE: To evaluate the efficacy of selective laser trabeculoplasty (SLT) to lower intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG), normal tension glaucoma (NTG) or ocular hypertension (OHT), when performed with laser pulse duration of 1 ns compared with standard 3-5 ns. METHODS: Bilateral SLT with a 532 nm Q-switched neodymium-doped yttrium aluminium garnet laser was conducted in 30 patients (60 eyes) with POAG (n = 5), NTG (n = 2) or OHT (n = 23). Pulse duration was 1 ns in the right eye (30 eyes; cases) and 3-5 ns in all left eyes (controls). Main outcome measures were IOP at 1 h, 1 day, 8 weeks and 6 months, and the rate of adverse ocular tissue reactions in all eyes. RESULTS: Mean 1 ns and 3-5 ns SLT IOPs were 24.1 and 24.3 mmHg, respectively, at baseline. No statistically significant difference in mean 1 ns and 3-5 ns SLT IOP was observed at 1 h (P = 0.761), 1 day (P = 0.758), 8 weeks (P = 0.352) and 6 months postoperatively (P = 0.879). No significant difference in postoperative anterior chamber inflammation was observed between the eyes (P = 0.529). Treatment with both laser pulse durations resulted in minor ultrastructural changes in the drainage angle. CONCLUSIONS: SLT performed with a 1 ns laser pulse duration does not appear to be inferior to SLT performed with the standard 3-5 ns duration at lowering IOP in treatment-naïve patients with POAG, NTG or OHT.

Palladium-103 plaque radiation therapy for ciliary body melanoma through a functioning glaucoma filtering bleb.

PURPOSE: To provide a clinical description of the long-term outcome of a 103Pd plaque-irradiated ciliary body melanoma with extrascleral extension while attempting to preserve a subadjacent glaucoma filtering bleb. METHODS: A 75-year-old woman with pseudoexfoliative glaucoma for 17 years, 16 years status post argon laser trabeculoplasty, and 15 years status post trabeculectomy in the left eye, was diagnosed with an ipsilateral ciliary body melanoma with visible extrascleral extension. Treatment involved insertion of a 103Pd radioactive plaque over the functioning trabeculectomy, with removal 7 days later. At plaque insertion, amniotic membrane grafts were used to cover the plaque and protect the filtering site. RESULTS: The tumor was successfully treated without clinical evidence of harm to the filtering bleb, with resultant stable intraocular pressure. However, the patient developed blebitis 1.5 years later. Though it resolved with topical antibiotic therapy, the bleb became less succulent. Two years postoperatively, she developed a spontaneous hyphema that resolved after one injection of transscleral bevacizumab 1.25 mg. Her tumor continually regressed in thickness. Without additional glaucoma surgery, her intraocular pressure remained well-controlled on topical medications for 6 years. CONCLUSIONS: Ciliary body melanoma with minimal extrascleral extension beneath a functioning filtering bleb can be treated using radioactive plaque therapy. In this case, we were able to achieve both tumor regression and glaucoma control by covering the plaque with an amniotic membrane graft.

Effects of a high level of illumination before sleep at night on chorioretinal thickness and ocular biometry.

The choroid is affected by many factors. One of the factors, change in illumination has been suggested to influence choroidal thickness. However, the effects of bright light before sleep at night on the human eye are not well established. The purpose of this study was to investigate the effects of a high level of illumination in the evening on ocular measurements. Twenty-seven men with myopia spent seven consecutive nights in the sleep laboratory. During the first two nights, subjects were exposed to light at 150 lux between 20:00 and midnight. Then, for five consecutive nights, they were exposed to ambient light at 1000 lux between 20:00 and midnight. Ocular parameters and their diurnal variations were compared between the two periods and the effects of a high level of illumination were analyzed. After subjects were exposed to 1000 lux of illumination, axial length increased with borderline significance (p = 0.064). Macular volume and retinal thickness did not change. However, subfoveal choroidal thickness after exposure to 1000 lux of illumination (245.37 ± 52.84 µm) was significantly lower than that after 150 lux of illumination (268.00 ± 57.10 µm), (p < 0.001). Significant diurnal variations were found in mean keratometry (p = 0.039), intraocular pressure (IOP, p = 0.003), ocular perfusion pressure (OPP, p < 0.0001), macular volume (p = 0.019), and subfoveal choroidal thickness (p < 0.0001). A high level of illumination had significant effects on only IOP and OPP (p = 0.027 and 0.017, respectively). Bright light exposure before sleep at an intensity as high as 1000 lux reduced subfoveal choroidal thickness in healthy young men. In conclusion, diurnal variation in choroidal thickness can be affected by bright light exposure before sleep.

Establishment and Characterization of an Acute Model of Ocular Hypertension by Laser-Induced Occlusion of Episcleral Veins.

Purpose: This study was designed to develop and characterize a laser-induced model of acute intraocular hypertension that permits the study of the anterior segment of the eye. Methods: CD1 mice aged 5 and 8 weeks were examined for elevation of IOP induced by laser photocoagulation. We compared between occlusion of episcleral veins alone and when combined with 270° limbal vessel occlusion. Anterior chamber angle, corneal thickness, and retinal nerve fiber layer (RNFL) thickness were evaluated by anterior- and posterior-segment optical coherence tomography (OCT). Additionally, at day 7 post-procedure, the anterior segment was evaluated for inflammatory cellular presentation by histologic analysis and OCT, and limbal vessels and whole-mount retina were immunostained for CD31 and Brn3a, respectively. Brn3a-positive retinal ganglion cells (RGCs) were quantified with ImageJ software. Results: After single or combined laser treatment in mice aged 5 or 8 weeks, IOP was significantly elevated for 5 to 6 days before returning to the baseline by day 7 post-procedure. Anterior segment assessment indicated less synechiae in the anterior chamber angle and better preserved limbal vessels with single versus combined laser treatment. Corneal thickness was significantly increased after single or combined treatment. No inflammatory cells were detected in the anterior chamber. The thickness of the RNFL and the density of RGCs were both significantly reduced after single or combined treatment. Conclusions: Laser photocoagulation of episcleral veins alone in CD1 mice aged 5 to 8 weeks may be used to induce ocular hypertension resulting in RNFL thinning and ganglion cell loss. This model permits the study of the anterior as well as the posterior segment of the eye.

Neovascular glaucoma after proton beam therapy of choroidal melanoma: incidence and risk factors.

PURPOSE: To analyze the risk factors for the development of neovascular glaucoma (NVG) of patients with choroidal melanoma after proton beam therapy (PBT). METHOD: Clinical case series, retrospective study. We evaluated 629 consecutive patients receiving proton beam therapy for the treatment of a choroidal melanoma at the oncology service at Charité, Berlin and Helmholtz-Zentrum, Berlin between 05/1998 and 11/2008 regarding the development and risk factors of NVG. Patients with tumor resection, salvage proton beam therapy for recurrent disease and known glaucoma of other origin were excluded from the cohort. RESULTS: Of the 629 patients matching the inclusion criteria, 20.8% developed neovascularization of the iris after a mean time of 2.0 years (range 0.45 to 8.4 years) after PBT. Forty-seven percent of the patients with a neovascularization of the iris developed NVG after a mean time of 2.0 years after PBT, ranging from 5 months to 11.6 years. Univariate analysis revealed tumor height [p < 0.001, hazard ratio (HR): 2.71, 95% confidence interval (CI): 1.36-5.35 for tumors >6 mm ≤9 mm and 11.32 (4.03-31.73) for tumors >9 mm], distance of the tumor to the optic disc (p < 0.001, HR: 0.43, 95% CI: 0.24-0.77 for >0 mm ≤3 mm and HR: 0.13, 95% CI: 0.04-0.37 for >3 mm), dose to the ciliary body (p < 0.001, HR: 9.21, 95% CI: 5.08-16.71 (21-40 cobalt gray equivalents (CGE), HR 27.23, 95% CI: 6.33-116.97 (41-60 CGE)), dose to the optic disc (p < 0.001, HR: 3.53, 95% CI: 1.11-11.27 (21-40CGE), HR: 5.37, 95% CI: 2.72-10.63 (41-60CGE)), the irradiated length of the optic nerve (p < 0.001, HR: 4.48, 95% CI: 2.47-8.13) and diabetes mellitus (p < 0.05, HR: 2.53, 95% CI: 1.4-4.5) were found to be risk factors for the development of NVG. Multivariate regression analysis identified the dose to the ciliary body [p < 0.001, HR: 4.39, 95% CI: 2.28-8.44 (21-40 CGE), HR: 11.04, 95% CI: 1.97-61.69 (41-60 CGE)], the irradiated length of the optic nerve (p < 0.001, HR: 3.88, 95% CI: 2.11-7.16), the existence of diabetes mellitus (p < 0.01, HR: 1.28, 95% CI: 1.24-4.21) and tumor height [p < 0.05, HR: 2.28, 95% CI: 1.17-4.83 (>6 mm ≤9 mm), HR: 3.74, 95% CI: 1.05-13.23, (>9 mm)] to be independent risk factors for the development of NVG. CONCLUSIONS: In the present analysis we found tumor height, dose to the ciliary body, irradiated length of the optic nerve and diabetes mellitus to be risk factors for the development of NVG. Whenever possible, critical structures of the anterior and posterior segment should be spared by beam shaping or changing of the beam entry angle.

Effect of Riboflavin/UVA Collagen Cross-linking on Central Cornea, Limbus and Intraocular Pressure. Experimental Study in Rabbit Eyes.

The Purpose of present study was to investigate the effect of riboflavin/ultraviolet-A-induced collagen cross-linking (CXL) on central cornea, limbus and intraocular pressure (IOP). This was an animal experimental study. The right corneas of 10 rabbits were ultraviolet-A irradiated (3 mW/cm2 for 30 minutes) after de-epithelialization and instillation of 0.1% riboflavin / 20% Dextran drops. Left corneas served as controls. Samples were examined histologically one month postoperatively. Before and after treatment, IOP measurements were recorded bilaterally. At central cornea of eyes underwent CXL keratocyte repopulation, normal arrangement of collagen fibres and a statistically significant change in fibres diameter were detected, compared to controls. At limbus area, there were not any significant histological differences after CXL. There was no statistically significant difference between pre- and postoperative IOP in all eyes.

Intraocular pressure fluctuations of growing chick eyes are suppressed in constant light conditions.

We report measurements of intraocular pressure (IOP) in growing domestic chicks at 12 h intervals, with three different lighting conditions. One group of chicks was raised in 12 h light and 12 h darkness (N), another in constant light (CL), and the third group was initially exposed to CL for three weeks then returned to N for either one week or four weeks (CLN). Pressures were measured in the middle of the light and dark periods (noon and midnight) for N and CLN birds, and at corresponding 12 h intervals for CL birds (also noon and midnight). The IOP of N chicks fluctuated from a light period average value of 25 mm Hg ( ±1.3 SD), to a dark period average value of 17.5 mm Hg ( ±1.1 SD mm Hg; P < 0.0001). These pressures were established by 4 days of age. At 7 weeks, (N) IOP continued to fluctuate: light values were 21.7 mm Hg (±1.2 SD), and dark values were 18.3 mm Hg ( ±0.7 SD). The IOP of CL birds did not fluctuate, remaining steady at 17 mm Hg ( ±1.4 SD). Chicks exposed to CL for 3 weeks required more than one week in N to re-establish (N) IOP values. We conclude that IOP fluctuates in hatchling chicks under N light conditions, that fluctuation is suppressed in CL light conditions, and that IOP recovery from 3 weeks suppression in CL requires more than one week in N light conditions.

Evaluation of Color-Changing Effect and Complications After Nd: YAG Laser Application On Iris Surface.

BACKGROUND: The aim of this study was to evaluate the color-changing effect and adverse effects after Nd: YAG laser application on the iris surface of rabbit eyes. MATERIAL/METHODS: The study was performed on right eyes of 12 pigmented rabbits. A laser device that produces frequency doubled 532 nm wavelength Nd: YAG laser with 900 µm spot diameter was used. The laser was applied in 3 sessions at 2-week intervals, at energy levels of 0.8 mJ in Group A and 1.5 mJ in Group B. Slit-lamp examinations and measurements of intraocular pressure (IOP) using a Tono-Pen were performed before and 1 day after each laser session. Iris thickness (IT) was measured at the beginning and the end using an ultrasonic biomicroscope. The eyes were enucleated for histopathologic examination on day 60. RESULTS: On the first day after each laser session, maximum grade 1 anterior chamber flare and cells were observed in both groups. In all eyes, flare and cells disappeared at the end of the first week. There was no significant difference in the IOP and IT values between measurements performed prior to and after laser sessions during the study (p>0.05). None of the eyes showed complications such as corneal edema, hypopyon, posterior synechia, transillumination defect, or pupillary defect. In histopathological examinations, reduction in pigment density was more profound in Group B compared to Group A, which was statistically significant (p<0.019). CONCLUSIONS: There were no serious complications apart from mild transient inflammatory signs. Change in iris color was more evident at the end of the second month.

Treatment outcomes of micropulse transscleral cyclophotocoagulation in advanced glaucoma.

Glaucoma is the leading cause of irreversible blindness worldwide. The goal of this study was to describe our experience with the novel micropulse transscleral cyclophotocoagulation (MP-TSCPC; IRIDEX IQ810 Laser Systems, CA) in patients with advanced glaucoma. Patients with advanced glaucoma who underwent MP-TSCPC were included in our study. Laser settings were 2000 mW of 810 nm infrared diode laser set on micropulse delivery mode. The laser was delivered over 360° for 100-240 s. The duty cycle was 31.3 %, which translated to 0.5 ms of "on time" and 1.1 ms of "off time." Surgical success was defined as an intraocular pressure (IOP) of 6-21 mmHg or a reduction of IOP by 20 % at the last follow-up visit. Failure was defined as an inability to meet the criteria for success or a need for incisional glaucoma surgery. Nineteen patients underwent MP-TSCPC with mean follow-up of 60.3 days. Mean IOP dropped from 37.9 mmHg preoperatively to 22.7 mmHg at last follow-up, representing a 40.1 % decrease. The success rate for initial treatment was 73.7 % (n = 14). Three patients underwent a second treatment, increasing the overall success rate to 89.5 % (n = 17). Four patients gained one line of vision, and four patients lost one line of vision. The novel MP-TSCPC laser had a high rate of surgical success after a short follow-up period in patients with advanced glaucoma. Further long-term evaluation and comparison to the traditional transscleral cyclophotocoagulation are warranted.