Anterior movement of the crystalline lens in the process of accommodation in children.

PURPOSE: To investigate changes of crystalline lens position during accommodation in children with emmetropia, myopia, and hyperopia. METHODS: A total of 188 children (372 eyes) from 4 to 19 years old (mean age 11.3+/-4.43) with cycloplegic refractive error within a range +9.00 D to -9.00 D were enrolled. After a general ophthalmic examination, ultrasound biometry was performed, with the eye at a maximal accommodative effort. Cycloplegia was induced by triple installation of 1% tropicamide drops and 30 minutes later the biometric examination was repeated. RESULTS: In emmetropic eyes in the process of accommodation, the anterior pole of the crystalline lens moved forward by 0.144+/-0.14 mm (p< or =0.001); the position of the posterior pole did not change. In myopic eyes, the anterior pole moved forward by 0.071+/-0.13 mm (p< or = 0.001) and the posterior pole moved backward by 0.039+/-0.10 mm (p=0.003). In hyperopic eyes, the whole lens translocated anteriorly: anterior pole moved forward by 0.242+/-0.16 mm (p< or = 0.001) and posterior pole moved forward by 0.036+/-0.09 mm (p< or = 0.001). Differences among emmetropia, myopia, and hyperopia were statistically significant. Forward movement of the posterior pole correlated with a low axial length of the eye, and also with plus refractive error and with a smaller accommodative increase of lens thickness. CONCLUSIONS: In children, accommodative changes of the crystalline lens position depend on refractive status.

Retinal imaging by spectral optical coherence tomography.

PURPOSE: To demonstrate applicability of high speed spectral optical coherence tomography (SOCT) method for imaging retinal pathologies in clinical conditions. METHODS: SOCT was performed in 67 eyes with different macular diseases. Examinations were carried out with the prototype SOCT instrument constructed in the Institute of Physics, Nicolaus Copernicus University, Torun, Poland. A broadband superluminescent diode was used as a light source. RESULTS: The disturbances of retinal layer structure concerning mainly outer segments of photoreceptors were observed in case of central serous chorioretinopathy and choroidal neovascularization in age-related macular degeneration. Large drusen were often related to significant changes of outer nuclear layer thickness and reflectivity. CONCLUSIONS: SOCT detects small disturbances of the retinal structure and helps to precisely determine layers involved in different pathologies.

[Evaluation of the surface of the new intraocular lenses in the scanning electron microscope]. / Ocena powierzchni nowych soczewek wewnatrzgalkowych w elektronowym mikroskopie skaningowym.

PURPOSE: To evaluate the surface of the new PC IOLs commercially available in Poland in 2000. MATERIAL AND METHODS: Representative samples of new posterior chamber IOLs produced by 6 different companies (Alcon, Lensita, Medicontur, Opsia, Rayner, Storz), 5 of each, underwent surface examination with Novoscan 30 scanning electron microscope. RESULTS: Although, in general, smooth surface of optic and haptic parts were observed, three samples with irregularities were found. CONCLUSIONS: Comparing to previous evaluation performed in 1994, significant improvement in quality of IOLs surface was noted. No considerable differences in this field between above mentioned producers were observed.

[Post-steroid elevations of intraocular pressure in patient after radial keratotomy]. / Posteroidowe zwyzki cisnienia wewnatrzgalkowego u osób po keratotomii radialnej.

PURPOSE: The evaluation of frequency and amplitude of IOP elevations in patients after RK who were administrated topically dexamethasone. MATERIAL AND METHODS: RK was carried out in 90 eyes (55 patients). All these patients had been treated topically with 0.1% dexamethasone (Maxitrol, Alcon) since the first day after surgery till the period of 3 months in lowering doses. IOP was measured using air-puff tonometer (Reichert, USA) before surgery and on 1, 2, 3, 14, 30, 50, 90 day after RK. In case of IOP elevations the measurements were made more often. RESULTS: The mean IOP before surgery was 14.88 +/- 2.86 mm Hg for women and 16.14 +/- 2.83 mm Hg for men. In the period of 3 months after RK maximum IOP increased significantly both for women (mean: 21.46 +/- 7.51 mm Hg) and men (mean: 26.14 +/- 8.87 mm Hg). IOP higher than 25 mm Hg was observed in 35 eyes (37.7%). These IOP elevations were observed more often in men than women but this difference was not statistically significant. There was no correlation between frequency of IOP elevations and preoperative refractive error or the age of patients. CONCLUSIONS: The usage of steroids after RK requires careful monitoring of IOP. This subject needs further studies to answer if these IOP elevations can damage eye functions.