Unterlauft J.D.,University Eye Hospital Wuerzburg |
Unterlauft J.D.,University of Leipzig |
Elsasser K.,University Eye Hospital Wuerzburg |
Haigis W.,University Eye Hospital Wuerzburg |
And 2 more authors.
International Ophthalmology | Year: 2015
The purpose of this study was to analyse and compare the visual and refractive results afterDSEKwith manual donor dissection and DSAEK with microkeratome- assisted donor dissection in a retrospective unmasked case control study. DSEK was performed in 15 eyes of 15 patients (74.9 ± 7.9 years; 4♂, 11♀). DSAEK was performed in 15 eyes of 15 patients (76.5 ± 6.6 years; 4♂, 11♀) using the Carriazo-Pendular- microkeratome andSchwindt artificial anterior chamber. The best corrected visual acuity (BCVA), corneal geometry assessed using Scheimpflug photography (SP) and anterior segment optical coherence tomography (ASOCT) was regularly measured in 15 matched pairs receiving DSEK or DSAEK. Mean BCVA improved from 1.1 ± 0.5 to 0.5 ± 0.2 logMAR (p = 0.001) after DSEK and from 1.0 ± 0.5 to 0.2 ± 0.2 logMAR (p = 0.001) in the DSAEK-group. After 6 months, BCVA was significantly better in the DSAEK-group. Corneal refractive power decreased from 36.9 ± 1.5 to 35.9 ± 1.3 D (p = 0.01) in the DSEK-group and from 37.7 ± 1.6 to 36.4 ± 1.6 D (p = 0.01) in the DSAEKgroup. The corneal back surface radius changed from 6.05 ± 1.6 to 5.82 ± 0.45 in the DSEK (p = 0.03) and from 6.72 ± 0.96 to 5.39 ± 0.33 in the DSAEK-group (p = 0.01). Mean central corneal thickness (CCT) measured by SP decreased from 741 ± 105 to 605 ± 63 µm (p = 0.26) after DSEK and from 700 ± 98 to 607 ± 88 µm (p = 0.01) after DSAEK. At no point in time during follow-up, mean CCT was significantly different in both groups. The ratio between central and peripheral transplant thickness decreased slightly from 0.65 ± 0.16 to 0.59 ± 0.16 after DSEK (p = 0.57) and from 0.52 ± 0.08 to 0.43 ± 0.14 after DSAEK (p = 0.17). The ratio difference between DSEK and DSAEK-groups was not statistically significant. The use of a pendular microkeratome for DSAEKresults in faster visual rehabilitation but does not decrease the surgically induced change of cornea-based hyperopisation which is due to posterior corneal curvature. © Springer Science+Business Media Dordrecht 2014.
Reichl S.,TU Braunschweig |
Borrelli M.,University Eye Hospital Wuerzburg |
Borrelli M.,The Second University of Naples |
Geerling G.,University Eye Hospital Wuerzburg
Biomaterials | Year: 2011
Human amniotic membrane (AM) is frequently used as a substrate for ocular surface reconstruction. Its disadvantages (e.g., reduced transparency and biomechanical strength, heterogeneity depending on donor) create the need for standardized alternatives. Keratin from hair or wool has been proposed as an appropriate material for producing films or cell cultivation scaffolds. The current study was performed to develop transparent, stable and transferable films based on human hair keratin that support cellular adhesion and proliferation. The films were engineered by a multi-step procedure including keratin extraction, neutral and alkaline dialysis, drying and a curing process. Keratin films were investigated by SDS-PAGE, SEM and X-ray analyses. Furthermore, swelling and water absorption of the films were studied, as were tensile strength and light transmission (UV/VIS). Finally, the growth behavior of corneal epithelial cells on the keratin films and AM was estimated in proliferation studies. In addition, we assessed the seeding efficiency and cell detachment behavior during trypsinization. The film-forming process resulted in transparent films composed of nanoparticulate keratin structures. The film characteristics could be varied by changing the protein composition, adding softening agents or varying the curing temperature and duration. Based on these findings, an optimized protocol was developed. The films showed improved light transmission and biomechanical strength in comparison to AM. Furthermore, cell behavior on the films was similar to that found on AM. We conclude that keratin films may represent a new, promising alternative for ocular surface reconstruction. © 2011 Elsevier Ltd.
PubMed | University Eye Hospital Wuerzburg
Type: Comparative Study | Journal: Cornea | Year: 2011
We performed a comparative study using Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) to measure intraocular pressure (IOP) in eyes with keratoconus.IOP was measured in 114 eyes of 75 patients with keratoconus (51 men and 24 women; mean age, 36.1 11.2 years) using GAT and DCT in randomized order. Central corneal thickness (CCT), minimal corneal thickness (MCT), and corneal topography were recorded using the Pentacam. Four groups according to Amslers keratoconus classification were composed and analyzed for significant differences of CCT, MCT, GAT, and DCT results.Mean CCT in the 114 keratoconus eyes was 481.1 46.2 m (range, 334-601 m). Mean MCT was 453.3 56.3 m (range, 239-573 m). Mean IOP measured using GAT was 13.1 2.9 mm Hg, whereas mean IOP measured using DCT was 14.8 2.6 mm Hg. Neither the results for GAT nor those for DCT showed a significant correlation with CCT (Pearson correlation: P < 0.05). Multifactorial analysis revealed that CCT and MCT, but not GAT and DCT, results were significantly different in corneas of varying curvatures.This study shows that DCT measures IOP higher than GAT in eyes with keratoconus. In keratoconus, both methods seem to be independent of CCT and therefore are equally, but not interchangeably, applicable when monitoring IOP. Further analysis revealed that CCT and MCT are significantly different in corneas of varying Amsler grade.