Use of a T-flex toric intraocular lens to correct clinically significant astigmatism

AbstractPurposeTo investigate the stability and effectiveness of T-flex toric intraocular lenses (IOLs) for the correction of regular corneal astigmatism during cataract surgery.MethodsFrom October 2009 to January 2014 we enrolled patients receiving phacoemulsification and T-flex toric IOL implantation in the capsular bag at the Far Eastern Memorial Hospital. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal astigmatism, refractive astigmatism, and the degree to which the IOL axis deviated from the demanded axis were recorded both before the operation and 6 months postoperatively.ResultsWe enrolled 24 eyes of 24 consecutive patients in this study. The mean spherical power of the implanted toric IOLs was 17.13 ± 4.21 D (range 6.0–24.0 D) and the mean cylindrical power of the IOLs was 3.0 ± 0.86 D (range 2.0–5.0 D). At the 6-month follow up examination, the refractive astigmatism had improved from 3.21 ± 1.50 D to 0.77 ± 0.47 D (p < 0.001) and the spherical equivalence had improved from 4.47 ± 5.43 D to 0.63 ± 0.49 D (p = 0.007). The CDVA improved from 0.81 ± 0.45 logMAR to 0.09 ± 0.11 logMAR (p < 0.001). The mean improvement from the preoperative CDVA to the postoperative UDVA was 5.3 lines on the Snellen chart. Ninety-two percent of our patients achieved a postoperative UDVA ≥20/40 and 67% achieved a postoperative UDVA ≥20/25.ConclusionThe T-flex toric IOL can effectively reduce visually significant corneal astigmatism and improve uncorrected distance visual acuity during cataract surgery

Long-term survival of allogeneic donor cell-derived corneal epithelium in limbal deficient rabbits

Purpose. To investigate the capability of cultivated allogeneic epithelial stem cells to restore a functional ocular surface in a limbal deficient cornea; to verify the long term survival of epithelial allograft; and to examine the host immune response to heterologous cell transplant in a rabbit model. Methods. Limbal deficiency was established by performing limbectomy on rabbits (n = 100). Corneal epithelial stem cells were obtained from the limbus and replicated in vitro without a supporting layer. The cell (3 × 10 5) suspension was then transplanted via topical application as eye drops. Animals were divided into allograft, autograft, and control groups. Females were used as recipients and males as donors for the allograft. Corneas were collected at 7, 14, 21, 40 days as well as 2, 3, 7 and 8 months after cell transplantation. Experimental corneas were evaluated by histology, immunofluorescence, immunohistochemistry and Y chromosome analysis. Results. A well-differentiated corneal epithelium was recognized at 14 to 40 days after cell transfer overlying an infiltrated corneal stroma. Corneal re-epitheliazation was confirmed in 31 of 36 allograft corneas. No significant immune rejection was noted. Stromal abnormality caused by previous limbal deficiency was mostly resolved three months after the regeneration of corneal epithelium. Conclusions. Transplanted corneal epithelial stem cells were able to differentiate into normal corneal epithelium in vivo without the use of membrane scaffolding. This non-autologous donor cell-derived corneal epithelium survived up to 8 months without immunosuppression and was able to reverse the stromal scarring. Thus, cultivated epithelial stem cells have great potential as an alternative to multiple-surgical procedures in the treatment of limbal deficiency states