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.

Influence of hyperbaric oxygen therapy on central corneal thickness.

BACKGROUND/AIMS: Hyperbaric oxygen (HBO) therapy is used in the treatment of several disorders. Little is known about the effects of HBO treatment on corneal thickness. The aim of this study was to investigate the effect of HBO treatment on central corneal thickness. METHODS: Thirty-two subjects (18 males and 14 females, mean age 57.3 ± 16.7 years) undergoing HBO treatment were consecutively enrolled. The subjects were assigned into diabetic (n = 16) and nondiabetic groups (n = 16). Best-corrected visual acuity was recorded before HBO treatment, and anterior and posterior segment examinations were performed on a slit lamp biomicrosope. Central corneal thickness was measured with an ultrasonic pachymeter before and immediately after HBO treatment, which lasted 120 min at 2.4 atmospheres absolute with three 30-min oxygen and two 5-min air breathing periods. RESULTS: HBO treatment did not change the central corneal thickness in diabetic subjects (547.6 ± 34.5 vs. 548.6 ± 34.6 µm; p = 0.606). In nondiabetic subjects, however, the central corneal thickness was significantly reduced after HBO treatment (576.5 ± 34.8 vs. 569.0 ± 34.8 µm; p < 0.001). CONCLUSION: A single exposure to HBO treatment reduced the central corneal thickness in nondiabetic subjects but not in diabetic subjects. However, the change in central corneal thickness was minor.

Selective laser trabeculoplasty induced changes in the thickness of ciliary body and iris evaluated by ultrasound biomicroscopy.

BACKGROUND: Selective laser trabeculoplasty (SLT) is widely used for the treatment of glaucoma. The main target tissue of this treatment modality is trabecular meshwork. We aimed to detect the SLT-induced changes in the thickness of ciliary body (CBT) and iris (IT), quantitatively. METHODS: Thirty-one patients treated by SLT were examined by ultrasound biomicroscopy (UBM) at different locations of ciliary body and iris at four quadrants, before and after (3rd, 7th, and 30th days) SLT. The IT was measured at various locations; 500 µm anterior to the scleral spur (IT(1)), 2 mm from the iris root (IT(2)) and near the pupillary edge where the iris thickness was maximum (IT(3)) at four quadrants. The CBT at positions 1 and 2 mm posterior to the scleral spur were measured (CBT(1-2)). Additionally, intraocular pressure (IOP) levels were measured in all visits and post-laser 1 h. RESULTS: There were statistically significant higher CBT values at 3rd and 7th-day measurements in the study compared to pre-treatment levels (p < 0.0001, p < 0.0001, respectively). CBT(2) values at day 30 were similar compared to pre-treatment values (overall p = 0.140), but CBT(1) values at day 30 were not exactly similar compared to pre-treatment values in superior and nasal quadrants (overall p = 0.027). IT values obtained in the 3rd and 7th days were significantly higher in all quadrants and regions when compared to the pre-treatment values (p < 0.0001, p < 0.0001, respectively). There were no statistically significant differences in any of the IT values at the 30th day in comparison to the pre-treatment values (p = 0.45). CONCLUSIONS: The results suggest that SLT induces prominent increases in CBT and IT returning to baseline thickness in a month, which may be caused by inflammation, vascular engorgement, or mechanical muscular contraction.

Autofluorescence findings in Vogt-Koyanagi-Harada disease.

PURPOSE: To report shortwave autofluorescence (SW-AF) and near infrared autofluorescence (NIR-AF) findings in a case of Vogt-Koyanagi-Harada (VKH) disease. METHODS: A 22-year-old man presented with a 2-week history of headache, moderate hearing loss, discolored hair, and bilateral gradually decreased vision (20/800 bilaterally). Ophthalmologic examinations revealed bilateral granulomatous anterior uveitis and multiple patchy bullous retinal detachments. Fundus fluorescein angiography (FFA), SW-AF, and NIR-AF imaging were performed with a confocal scanning laser ophthalmoscope at the beginning and after resolution. The patient responded well to systemic prednisolone treatment. Visual acuity and hearing loss improved quickly (visual acuity 16/20 bilaterally). RESULTS: Multilobular dye pooling with a dark rim was observed in serous detached retinal areas on late-phase FFA. These areas were observed as hypoAF in SW-AF and NIR-AF mode due to the blockage. After resolution of serous detachment, numerous hypoAF granular dots were observed scattered over the previously serous detached areas in SW-AF and NIR-AF mode. These hypoAF granular dots were seen as window defect lesion in FFA and interpreted as retinal pigment epithelial damage or atrophy. CONCLUSIONS: SW-AF and NIR-AF imaging confirmed granular retinal pigment epithelium atrophy which corresponds to FFA findings. SW-AF and NIR-AF imaging methods are noninvasive and useful techniques for documentation of fundus changes in VKH disease.

Carbon monoxide-induced cortical visual loss: treatment with hyperbaric oxygen four years later.

OBJECTIVE: We present a patient who developed visual loss after carbon monoxide (CO) poisoning and was treated with hyperbaric oxygen. CLINICAL PRESENTATION AND INTERVENTION: A 21-year-old woman poisoned with CO (with coma lasting 4 h and carboxyhemoglobin level 46%) developed seizures and cortical blindness 3 days after poisoning. Four years later, her visual acuity was 0.2 in both eyes. An (18)F-fluorodeoxyglucose positron emission tomography (PET) scan showed reduced metabolism in the bilateral posterior temporal and occipital lobes. The patient received a total of 50 hyperbaric oxygen sessions over 3 months for visual loss and the visual acuity improved to 0.5 in both eyes. In addition, increased metabolism was detected in the brain in post-treatment PET scans. CONCLUSION: PET documented brain hypoperfusion 4 years after CO poisoning and hyperbaric oxygen therapy improved visual acuity. However, we cannot endorse routine use of hyperbaric oxygen for such patients, until results of further clinical trials demonstrate efficacy of hyperbaric oxygen in CO-induced chronic brain injury.

Validation of the ocular trauma score for intraocular foreign bodies in deadly weapon-related open-globe injuries.

BACKGROUND AND OBJECTIVE: To evaluate the prognostic value of the Ocular Trauma Score (OTS) in cases of deadly weapon-related open-globe injuries with intraocular foreign bodies. PATIENTS AND METHODS: A retrospective, interventional case series included 20 eyes of 20 patients who had deadly weapon-related open-globe injuries with intraocular foreign bodies. The OTS was calculated for each patient by adding the determined numbers of OTS variables at presentation (initial visual acuity, rupture, endophthalmitis, perforating injury, retinal detachment, and afferent pupillary defect). Patients were categorized based on their score (category 1 through 5). Final visual acuities in the OTS categories were calculated and compared to those in OTS study group. RESULTS: No statistically significant difference was found between the categorical distributions of the study patients and those in the OTS study group. No patient in the study was in category 5. CONCLUSION: The OTS, which was designed to predict visual outcomes of general ocular trauma, may also provide reliable information about the prognosis of deadly weapon-related open-globe injuries with intraocular foreign bodies.

Cytokine profile in Behçet uveitis.

OBJECTIVES: Investigate the role of cytokines in Behçet uveitis. BACKGROUND: Cytokines may take part in this pathogenetic mechanism. Elevated and/or altered levels of specific cytokines have been found in patients with Behçet's disease in many studies. METHODS: Twenty patients with Behçet uveitis and 20 patients with Behçet's disease without uveitis were included to the study in compliance with International Study Group Criteria. Twenty non-Behçet uveitis patients were included in the study. In this group, active uveitis was found in 30 % and arthritis in 35% of patients. Serum levels of cytokines (Interleukin-2-4-6-8, IL-2-4-6-8), tumor necrosis factor-alpha, TNF-alpha) and local growth factor (vascular endothelial growth factor, VEGF) were measured. RESULTS: Levels of all cytokines were highest in Behçet patients without uveitis except for IL-2 and IL-6. These cytokines were also highest in patients with non-Behçet uveitis too. Despite the tendency of this distribution of cytokines, only three cytokines, TNF-alpha, IL-8 and IL-4 were significantly different from the controls. The levels of TNF-alpha, IL-8 and IL-4 were significantly lower in patients with Behçet uveitis than in Behçet patients without uveitis. Interestingly, the levels of IL-2 and IL-6 were statistically similar in all groups. VEGF showed no significant difference between the studied and control groups. However, in contrast to cytokines, only the levels of VEGF were correlated with the activity of uveitis (p<0.05). CONCLUSION: Consistent with previous reports of different immune effectors in Behçet uveitis, it may be suggested that its underlying immunopathogenesis may be much different from other causes of endogenous uveitis (Tab. 3, Fig. 1, Ref. 20). Full Text (Free, PDF) www.bmj.sk.

Photodynamic therapy for posterior capsule neovascularization.

We report a 71-year-old man with posterior capsule opacification with severe neovascularization who was treated with photodynamic therapy and neodymium:YAG capsulotomy. Treatment was performed using a diode laser at 692 nm, a light dose of 50 J/cm(2), and 6 mg/m(2) body surface area verteporfin. The initial visual acuity was hand motions; 6 months after therapy, the visual acuity was stable at 20/200. In 9 months of follow-up, there was no recurrence of neovascularization and the pupil area remained clear; no retreatment was needed. Photodynamic therapy provided safe and effective occlusion of neovascular vessels in the posterior capsule area.

A predictive score for retinopathy of prematurity by using clinical risk factors and serum insulin-like growth factor-1 levels.

AIM: To detect the impact of insulin-like growth factor-1 (IGF-1) and other risk factors for the early prediction of retinopathy of prematurity (ROP) and to establish a scoring system for ROP prediction by using clinical criteria and serum IGF-1 levels. METHODS: The study was conducted with 127 preterm infants. IGF-1 levels in the 1st day of life, 1st, 2nd, 3rd and 4th week of life was analyzed. The score was established after logistic regression analysis, considering the impact of each variable on the occurrences of any stage ROP. A validation cohort containing 107 preterm infants was included in the study and the predictive ability of ROP score was calculated. RESULTS: Birth weights (BW), gestational weeks (GW) and the prevalence of breast milk consumption were lower, respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD) and necrotizing enterocolitis (NEC) were more frequent, the duration of mechanical ventilation and oxygen supplementation was longer in patients with ROP (P<0.05). Initial serum IGF-1 levels tended to be lower in newborns who developed ROP. Logistic regression analysis revealed that low BW (<1250 g), presence of intraventricular hemorrhage (IVH) and formula feeding increased the risk of ROP. Afterwards, the scoring system was validated on 107 infants. The negative predictive values of a score less than 4 were 84.3%, 74.7% and 79.8% while positive predictive values were 76.3%, 65.5% and 71.6% respectively. CONCLUSION: In addition to BW <1250 g and IVH, formula consumption was detected as a risk factor for the development of ROP. Breastfeeding is important for prevention of ROP in preterm infants.

Intraocular pressure at a simulated altitude of 9000 m with and without 100% oxygen.

INTRODUCTION: Exposure to high altitude may affect intraocular pressure (lOP). This study aimed to determine how IOP was altered by two different inspired oxygen tensions at altitude. METHODS: There were 34 healthy male pilots, ages 26-39 yr (mean 31.9 yr), who were studied at the Air Health Examination and Physiological Training Centre in Eskisehir, Turkey. They were studied at ground level, which is 792 m (2414 ft), and during a training session in a hypobaric chamber at a simulated altitude of 9144 m (30,000 ft). IOP was measured with a Tone-pen XL tonometer before subjects entered the chamber, at altitude while breathing 100% oxygen by mask and after removing the mask, and again 30 min after leaving the chamber. RESULTS: Ground level values for IOP (mean +/- SD) were 12.31 +/* 2.98 mmHg. Levels increased significantly at altitude on oxygen (16.75 +/- 4.14 mmHg) and decreased slightly on breathing ambient air (14.37 +/- 3.44 mmHg). In 30 min after leaving the chamber, IOP was 12.81 +/- 1.74 mmHg, indistinguishable from pre-test values. DISCUSSION: Healthy subjects whose baseline IOP is in the normal range experience only a small, temporary elevation of IOP during passive exposure to high altitude with either normoxia or acute hypoxia.

Results of pars plana vitrectomy in closed-globe injuries.

BACKGROUND AND OBJECTIVE: To assess surgical and visual outcomes with pars plana vitrectomy (PPV) in closed-globe injuries resulting in anterior and posterior segment pathologies and evaluate the factors influencing the prognosis. PATIENTS AND METHODS: Retrospective observational study. Forty-seven eyes of 47 consecutive patients who underwent PPV because of closed-globe injury between January 1992 and August 2003 were reviewed. Surgical and visual outcomes and prognostic factors were analyzed according to the Ocular Trauma Classification System. RESULTS: Preoperative visual acuity was less than 4/200 in 49% of eyes, classified as grades IV to V. After surgery, this ratio was 23% (P < .05). Final visual acuity was statistically significantly better in grade I (P = .0001), grade II (P = .002), and relative afferent pupillary defect-negative (P = .0001) injuries. Maculopathy was the most common adverse outcome influencing final visual acuity (32%), followed by secondary glaucoma (13%) and proliferative vitreoretinopathy (8%). CONCLUSION: PPV is a favorable treatment modality in severe closed-globe injuries. Assessment of injuries with respect to the Ocular Trauma Classification System seemed to predict visual outcomes in this series.

The efficacy of hyperbaric oxygen for the treatment of experimental uveitis induced in rabbits.

OBJECTIVE: The aim of the present study was to examine the efficacy of hyperbaric oxygen (HBO) therapy in the treatment of experimental uveitis induced in rabbits. It was hypothesized that HBO therapy improves the regression of experimental uveitis induced in rabbits. RESEARCH DESIGN AND METHODS: An experimental animal study was conducted on 48 rabbits (48 right eyes of these rabbits) to evaluate the effects of HBO therapy on endotoxin-induced acute anterior uveitis in rabbits. To induce acute anterior uveitis, Salmonella typhimurium lipopolysaccharide endotoxin (LPS) was intravitreally injected into the right eyes of the rabbits. The animals were randomly assigned to five groups. No treatment was given to the rabbits in Group A. Prednisolone acetate was topically administered to the rabbits in Group B. Methylprednisolone acetate was administered by anterior subtenon injection to the rabbits in Group C four hours after LPS application. HBO therapy was administered to the rabbits in Group D. Both HBO therapy and anterior subtenon injection of methylprednisolone therapy were administered to the rabbits in Group E. To compare the effects of the different therapies on the progression of endotoxin-induced uveitis, examinations including clinical scoring of anterior uveitis, microscopic examination of aspirated aqueous humor for inflammatory responses, and aqueous protein level assessment were performed once a day after LPS injection. RESULTS: There was a statistically significant difference between the control group (Group A) and other groups (Groups B-E) with respect to the number of inflammatory cells and protein levels in the aqueous one and three days after LPS injection (p < 0.05), indicating that the treatments resulted in less inflammation in Groups B-E compared to Group A. Moreover, there was no statistically significant difference between Groups B and C, Groups B and D, Groups B and E, Groups C and D, and Groups C and E with regard to the number of inflammatory cells in the aqueous at Day 1 after LPS injection (p > 0.05). In addition, Groups B and C and Groups B and D were comparable with regard to cell counts at Day 3 (p > 0.05), showing that HBO was comparable to corticosteroids in reducing inflammation. The differences between Groups B and E and Groups C and E were significant with regard to aqueous cell counts at Day 3 (p < 0.05), showing that HBO plus steroid was more effective than steroids alone. CONCLUSION: The intensity of ocular inflammation in the group receiving HBO therapy combined with anterior subtenon injection of methylprednisolone therapy was lower than in the other groups. We also demonstrated that HBO therapy was an effective therapeutic modality for the treatment of experimental uveitis induced in rabbits with an efficacy comparable to that of corticosteroids. Moreover, HBO plus steroid was superior to steroids alone in reducing inflammation.

Visual loss as a late complication of carbon monoxide poisoning and its successful treatment with hyperbaric oxygen therapy.

PURPOSE: To present recovery from vision loss due to CO poisoning with Hyperbaric Oxygen (HBO) therapy in two patients. METHODS: Two female patients developed visual deterioration after carbon monoxide (CO) poisoning and were treated with hyperbaric oxygen therapy (HBO). Clinical examination, including visual acuity assessment, visual field examination and visual evoked potentials (VEPs) before and after the HBO therapy were performed. RESULTS: In Case 1 the visual loss started on the third day with visual acuity at the level of perception of hand movements at 10 cm in the right eye and finger count at 10 cm in the left eye. The visual evoked potentials (VEPs) had low amplitudes and prolonged (128 msec bilaterally) latencies (implicit times). After 48 sessions and 52 days of HBO therapy, the visual acuity became 0.2 in the right eye and 0.15 in the left eye. Visual field examination revealed homonymous right lower quadrant anopsia. The VEPs also improved. In Case 2 the visual acuity was 0.2 in the right eye and 0.1 in the left eye on the 6th day following the accident when the patient was admitted for treatment. The VEP latencies were within normal limits. After 36 days and 35 sessions of HBO therapy, the visual acuity became 0.7 on both eyes. The visual fields completely normalised. The VEP latencies in this case also became shorter. CONCLUSION: It appears that the adverse effects of CO poisoning continue to progress during the late period and we believe that HBO treatment in this period may still be effective and will prevent some of the neurological sequelae such as visual loss from becoming permanent. Clinical, neurological, neuropsychological, visual outcome seems to be favourable even if HBO treatment started as late as 6 or 8 days after the exposure to CO.

Management of retinal detachment due to closed globe injury by pars plana vitrectomy with and without scleral buckling.

BACKGROUND AND PURPOSE: To investigate the effect of circumferential scleral buckling on the prognosis for patients undergoing pars plana vitrectomy and lensectomy for severe closed globe injury. METHODS: A total of 33 cases in which pars plana vitrectomy and lensectomy were performed after severe closed globe injury between January 1990 and January 2003 were studied retrospectively. All patients had zone III contusion type injury according to The Ocular Trauma Classification Group criteria. Of the 33 patients, 15 (group 1) also underwent peripheral scleral buckling; 18 did not (group 2). RESULTS: The mean age +/- SD was 34.8 +/- 17.5 years (range, 8-73 years). There were 6 female (18%) and 27 male (82%) patients. The two groups did not differ significantly in terms of preoperative visual acuity (P = 0.76) or postoperative visual improvement (P = 0.46). In groups 1 and 2, 4 (26%) and 3 (17%) patients developed recurrent retinal detachment for which they underwent reoperation. Other postoperative complications were as follows: group 1-phthisis (1 patient; 7%), proliferative vitreoretinopathy (1 patient; 7%), and optic atrophy (1 patient; 7%); group 2, proliferative vitreoretinopathy (2 patients; 11%) and optic atrophy (2 patients; 11%). CONCLUSION: Circumferential scleral buckling did not appear to offer advantages for patients undergoing pars plana vitrectomy and lensectomy for severe closed ocular injury involving the posterior chamber.