Corneal ablation with new 193 nm solid-state laser: preliminary experiments

PURPOSE: To assess the ability of a newly developed 193 nm solid-state laser to ablate the cornea. SETTING: Osaka University, Osaka, Japan. METHODS: A prototype laser engine was developed by combining a 1547 nm laser diode, fiber amplifiers, and 5 stages of a frequency-conversion system using CsLiB6O10 crystals as the last stage. Poly(methyl methacrylate) (PMMA) plates were exposed to the prototype laser beam to determine the relationship between the fluence and ablation rate. Laser irradiation of porcine corneas was performed to induce morphological changes, and the quality of the lesions was determined by light and scanning electron microscopy. RESULTS: The relationship between the fluence and ablation rate of the 193 nm solid-state laser was comparable to that of the argon-fluoride excimer laser. Light and scanning electron microscopy of the porcine corneas showed that the linear and square lesions had sharp, clean edges. CONCLUSIONS: Smooth ablations of PMMA plates and porcine corneas were obtained by the laser. Further investigations must be conducted to determine whether this laser can be an alternative laser source for keratorefractive surgery.     

Quantitative evaluation of reduction of plaque-like hard exudates in diabetic macular edema after intravitreal triamcinolone injection

Background To describe a new method of quantifying the amount of plaque-like hard exudates after intravitreal triamcinolone acetonide injection in diabetic macular edema. Methods This study included 22 eyes of 14 patients (mean age, 63 years) with chronic diabetic macular edema and plaque-like hard exudates. The patients were injected with a single dose of 4 mg intravitreal triamcinolone acetonide. The optic disc size as relative size unit was taken to quantify the hard exudates: Total areas of exudates and the optic nerve head were computed from fundus pictures with a digital analysis program on magnified images. The former was divided by the latter, and the results were expressed as a percentage value. The ratio was used to track improvements in a given eye over 6 months. Results Average ratio of hard exudates to optic nerve head area reduced to 81% of its initial value at 1 month (P = 0.007), to 54% at 3 months (P < 0.001) and to 41% at 6 months (P < 0.001). Conclusions The new method allowed detection of a significant reduction of ratio of hard exudates to optic disc area of diabetic plaque-like hard exudates following 4 mg intravitreal triamcinolone. This study was presented in part at the meeting of the American Society of Retina Specialists, Cannes, France, September 2006.     

Immediate intraocular pressure rise after intravitreal injection of ranibizumab and two doses of triamcinolone acetonide

AIM: To evaluate prospectively immediate intraocular pressure (IOP) changes after the intravitreal injection of ranibizumab, 2 and 4mg triamcinolone acetonide. METHODS: Patients who underwent intravitreal injection of 0.1mL (4mg) triamcinolone acetonide (TA, Group T4), 0.05mL (2mg) TA (Group T2) and 0.05mL (0.5mg) ranibizumab (Group R) comprised the study population. Overall, 229 eyes of 205 patients were injected. Fifty-four eyes (23.6%) were in Group T4, 69 eyes (30.1%) in Group T2 and 106 eyes (46.3%) in Group R. If IOP was less than 26mmHg immediately after the injection no further measurement was performed. If IOP was ≥26mmHg, IOP was remeasured till the reading was below 26mmHg at 5, 15 and 30 minutes. RESULTS: Immediately after the injection, the IOP of 28 eyes (51.9%) in Group T4, 22 eyes (31.9%) in Group T2 and 51 eyes (48.1%) in Group R were over 25mmHg. At 30 minutes, IOP of one eye (1.9%) in group T4, two eyes (2.9%) in group T2 and two eyes (1.9 %) in Group R were over 25mmHg. Immediate post-injection IOP was significantly higher in Group T4 and Group R when compared to Group T2 (P<0.001 and P<0.001, respectively). IOP was significantly higher in eyes without vitreous reflux when compared to those with vitreous reflux in all groups (P<0.001). CONCLUSION: IOP may remarkably increase immediately after the intravitreal injection of 2 or 4mg triamcinolone acetonide, and 0.5mg ranibizumab. Absence of vitreous reflux is the most important predicting factor for immediate IOP rise after the injection.     

Oculocerebrocutaneous syndrome

The authors describe a patient with oculocerebrocutaneous syndrome, also called Delleman-Oorthuys syndrome. This patient is the first reported case in Turkey. The 19-month-old boy had characteristic features of oculocerebrocutaneous syndrome, such as unilateral orbital cyst, skin tags and skin hypoplasia, hypoplastic left cerebellar hemisphere, Dandy-Walker variant anomaly, corpus callosum agenesis, and left cerebral hemispheric diffuse migration anomaly.     

Transfer of single dose of intravitreal injection of ranibizumab and bevacizumab into milk of sheep

AIM: To investigate whether single-dose intravitreal injections of bevacizumab and ranibizumab transfer into milk. METHODS: This study included lactating 12 sheep and a single 3-month old suckling lamb of each sheep. Two groups consisting of 6 sheep and their lambs were constituted; the ranibizumab group and the bevacizumab group before the administration of intravitreal injections, blood and milk samples were obtained from all sheep and, following the injections, blood and milk samples of all sheep and blood samples of all lambs were collected at regular time points. Serum and milk concentrations of bevacizumab and ranibizumab were measured using an enzyme-linked immunosorbent assay (ELISA) kit. The limit of determination was 0.9 ng/mL for bevacizumab and 0.62 ng/mL for ranibizumab. RESULTS: At 6h after intravitreal injections, bevacizumab concentration was above the limit of determination in the blood of all sheep. At 3wk, when the study was terminated, bevacizumab concentrations were high in 4 sheep. Even though bevacizumab concentrations in milk showed fluctuations, the drug transferred into the milk of all sheep at detectable concentrations. Ranibizumab drug concentrations in the blood and milk of sheep and those in the blood of lambs were below the limit of determination by the ELISA kit. CONCLUSION: This sheep model study demonstrate that intravitreal injection of ranibizumab, which did not transfer into the milk of sheep and suckling lambs, is safer than bevacizumab during lactation period.     

Retinal and Choroidal Thickness in Adult Patients with Familial Mediterranean Fever

Purpose: We aimed to evaluate changes in retinal, choroidal, ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL) thicknesses in genetically diagnosed adult patients with familial Mediterranean fever (FMF).

Methods: A total of 50 eyes of 50 genetically diagnosed patients with FMF and 50 eyes of controls were analyzed. Patients were recruited from the Genetic Diagnostic Center of D??kap? Y?ld?r?m Beyaz?t Research and Training Hospital, Turkey. Retinal and choroidal thicknesses were obtained using spectral-domain optical coherence tomography from choroid, retina, GCC, and RNFL.

Results: Average baseline choroidal thickness was statistically significantly thinner in patients with FMF than controls at C_center (325.85 ± 30.8 µm and 338.97 ± 23.9 µm, respectively, p = 0.038), C_nasal500 (328.77 ± 31.6 µm and 349.00 ± 23.3 µm, respectively, p = 0.002), C_nasal1000 (324.97 ± 33.6 µm and 351.23 ± 23.8 µm respectively, p = 0.0001) and C_nasal1500 (324.75 ± 37.1 µm and 344.61 ± 27.3 µm, respectively, p = 0.008). However, there was no significant difference in temporal choroidal thickness (C_temporal500, C_{temporal1000 and} C_temporal1500) in patients with FMF compared to controls (p > 0.05). There were no significant differences in retinal, GCC and RNFL thicknesses between the groups (p > 0.05).

Conclusion: We hypothesize that the chronic inflammation seen in FMF could be the reason for the reduction seen in choroidal thickness in adult patients with FMF. Retinal, GCC and RNFL thicknesses did not differ from controls.     

Is there an association between flow diverter fish mouthing and delayed-type hypersensitivity to metals?—a case-control study

Purpose

Flow diverters are increasingly used in the treatment of complex and giant intracranial aneurysms. However, they are associated with complications like late aneurysmal rupture. Additionally, flow diverters show focal structural decrease in luminal diameter without any intimal hyperplasia. This resembles a “fish mouth” when viewed en face. In this pilot study, we tested the hypothesis of a possible association between flow diverter fish-mouthing and delayed-type hypersensitivity to its metal constituents.

Methods

We retrospectively reviewed patient records from our center between May 2010 and November 2015. A total of nine patients had flow diverter fish mouthing. A control group of 25 patients was selected. All study participants underwent prospective patch test to detect hypersensitivity to flow diverter metal constituents. Analysis was performed using logistic regression analysis and Wilcoxon sign rank sum test. Univariate and multivariate analyses were performed to test variables to predict flow diverter fish mouthing.

Results

The association between flow diverter fish mouthing and positive patch test was not statistically significant. In multivariate analysis, history of allergy and maximum aneurysm size category was associated with flow diverter fish mouthing. This was further confirmed on Wilcoxon sign rank sum test.

Conclusion

The study showed statistically significant association between flow diverter fish mouthing and history of contact allergy and a small aneurysmal size. Further large-scale studies are needed to detect a statistically significant association between flow diverter fish mouthing and patch test. We recommend early and more frequent follow-up imaging in patients with contact allergy to detect flow diverter fish mouthing and its subsequent evolution.