A strip of partially hydrolyzed poly (2-hydroxyethyl methacrylate) containing 65%-75% H2O was implanted into the anterior eye chamber of 11 Chinchilla rabbits. No pathological changes were found in the iris or in the ciliary body. The pathological findings in the cornea accompanying implantation of a hydrogel strip to the anterior chamber were rare and not significant. The low occurrence of the foreign body giant multinucleate cells was observed on the implant surface 6 months after the implantation. Favorable properties of this hydrogel depend probably on its high water and acidic groups content.

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A practical demonstration of pH measurement in real biological samples with an in-house developed fiber-optic pH sensor system is presented. The sensor uses 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) fluorescent dye as the opto-chemical transducer. The dye is immobilized in a hybrid sol-gel matrix at the tip of a tapered optical fiber. We used 405 nm and 450 nm laser diodes for the dye excitation and a photomultiplier tube as a detector. The sensor was used for the measurement of pH in human aqueous humor samples during cataract surgery. Two groups of patients were tested, one underwent conventional phacoemulsification removal of the lens while the other was subjected to femtosecond laser assisted cataract surgery (FLACS). The precision of the measurement was ±0.04 pH units. The average pH of the aqueous humor of patients subjected to FLACS and those subjected to phacoemulsification were 7.24 ± 0.17 and 7.31 ± 0.20 respectively.

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The aim of this study was to evaluate the changes in IOL position (axial shift, tilt and decentration) in the capsular bag after Nd:YAG laser capsulotomy and to create a user-friendly software that is optimized for the output of available imaging technology, then verify the relationship between the biometric parameters of the eye and the extent of changes in the IOL position. Patients and Methods. The study included 35 artephakic eyes that underwent laser capsulotomy. Before and at least one hour after capsulotomy, all patients underwent the following assessments: optical biometry (Lenstar LS900), OCT with anterior segment module (Optovue Avanti) and IOL photography in infrared mode using reference unit (Verion). The original software solution was designed for the graphical evaluation of the differences between centering, axial displacement and tilt of IOL. Changes in IOL position were evaluated as simple differences before and after the laser procedure and as differences in absolute values (abs). Results. The following results show the average differences in IOL position: ACD=0.02±0.23 mm (abs=0.11±0.20 mm), IOL decentration in x-axis =-0.001±0.091 mm (abs=0.065±0.063 mm), IOL decentration in y-axis =0.012±0.119 mm (abs=0.048±0.53 mm), tilt in horizontal plane TILT-H=0.11±0.83° (abs=0.51±0.66°) and tilt in vertical plane TILT-V =-0.14±0.49° (abs=0.26±0.44°). All changes were insignificant (P>>0.05). In total, 74.29% of IOLs showed a hypermetropic shift. A moderate positive correlation was found between the absolute differences in horizontal tilt and keratometry (r=0.45). Relationship with other changes and parameters were weak. Conclusion. In conclusion, the use of the original software solution developed by the authors showed that changes in IOL centering, axial displacement and tilt occur after Nd:YAG capsulotomy, but average differences were insignificant. In almost 3/4 cases, there was a hypermetropic axial displacement of the IOL.

Purpose: Evaluation of the cost and effectiveness of therapy for patients with the wet form of age-related macular degeneration (AMD) in routine clinical practice. Methods: A retrospective multicentre evaluation of changes in the best-corrected visual acuity in applied kinds of therapy and a comparison with the cost of individual therapeutic procedures. Results: An overall total of 788 eyes of 763 patients with an average age of 73.2 ± 8.6 years was evaluated for a 1-year minimum period. In the ranibizumab and pegaptanib therapy groups, a reduction of 1.3 letters (p = 0.303) and 1.4 letters (p = 0.197) was found, respectively. In the group of photodynamic therapy (PDT) with verteporfin, a reduction of 5.2 letters was achieved (p < 0.001). Under the conditions of routine practice in the Czech Republic, the annual cost is highest (EUR 5,467.63/patient) in patients with pegaptanib therapy. The annual cost in patients with ranibizumab therapy is lower by EUR 1,220.16. The cost is nearly half (EUR 2,783.65) in the group treated with PDT with verteporfin. Conclusion: An initiation of AMD therapy by ranibizumab is cost-effective as compared to pegaptanib. Both ranibizumab and pegaptanib are significantly more efficient as compared to PDT with verteporfin. Therapy with ranibizumab and pegaptanib, as compared to PDT with verteporfin, prevents the loss of 1 line of vision on the ETDRS chart for EUR 1,225.98 and 2,286.18, respectively.

The study provides an up-to-date overview of pathogenesis, functional and structural changes in normal tension glaucoma (NTG) and its differences from high tension glaucomas (HTG). The authors point to less known facts which make both diagnostic groups different. First of all, there are electrophysiological findings that verify pathology in the complete visual pathway in HTG in contrast to NTG where the retinal ganglion cell response is relatively normal but the abnormalities are in the visual pathway. This corresponds to the findings of functional magnetic resonance imaging of the brain with a significant decrease in activity in HTG compared to NTG. We found a higher decrease in activity in HTG following application of the colour paradigm compared to NTG where we did not see a similar difference. We also investigated the central corneal thickness (CCT) in both diagnostic groups. We did not find a statistically significant difference. However, we found the effect of CCT on progression of the changes in visual fields in HTG. In relation to suspicion of abnormally low cerebrospinal pressure and a possible cerebrovascular fluid flow disturbance in NTG, we examined the optic nerve thickness (OND) and optic nerve sheath diameter (OSD) at a distance of 4, 8, 16 and 20mm from the posterior pole of the eye. In the comparison with the healthy population, we did not find any abnormalities except for the width of the optic chiasma that was markedly lower in NTG. In relation to a possible impairment of cerebral perfusion we determined the degrees of cerebral atrophy using magnetic resonance imaging by measuring the bicaudate ratio (BCR) and white matter lesions using the Fazekas scale. We did not find a difference between HTG and NTG in BCR. We found statistically significant changes in BCR which correlated with the changes in visual fields. The higher values of the pattern defect were associated with increased brain atrophy (BCR). We did not detect similar relations in the Fazekas scale. We found a significant difference in this parameter among NTG, HTG and a control group. We found the most advanced changes in the patients with HTG. Conclusion: In HTG, impairment of retinal ganglion cells and subsequently also their axons, including visual cortex occurs because of a high intraocular pressure. In NTG, the retinal ganglion cells are relatively normal like the visual cortex, but alteration occurs in their axons. The cause is not a high intraocular pressure but most probably ischemia.