Clinical performance of presbyopia correction with a multifocal corneoscleral lens

AIM:To assess the clinical performance of a multifocal corneoscleral lens for the presbyopia correction.METHODS:A prospective clinical trial of the OnefitTM A multifocal corneoscleral lens was conducted with 40 participants with presbyopia.At 4 wk of continuous wear of the corneoscleral lens,changes in the distance,intermediate,and near visual acuity(VA)were evaluated.The safety of the corneoscleral lens,central corneal thickness(CCT),corneal endothelial cell count,binocular stereopsis,tear film break-up time(BUT),corneal staining,corneal edema,corneal neovascularization(NV),and conjunctival hyperemia were examined.In addition,a subjective questionnaire addressing satisfaction(rated from 1 to 5 points)and discomfort(rated from 1 to 5 points)was administered.RESULTS:Forty participants were enrolled in this study.Six participants were excluded because of poor compliance with lens fitting(n=2)and loss to follow-up(n=4).The mean age of the participants was 53.0±4.9 y.At 4 wk of continuous wear of the corneoscleral lens,the best corrected far,intermediate,and near VA was 0.08±0.11,0.10±0.12,and 0.10±0.12 log MAR,respectively.These results were significant improvements over the baseline uncorrected VA(far:P=0.004;intermediate:P=0.004;near:P=0.002).CCT,corneal endothelial cell count,binocular stereopsis,BUT,corneal staining,corneal edema,corneal NV,and conjunctival hyperemia were not significantly different between baseline and after corneoscleral lens use.The average satisfaction scores for fit sensation;corrected far,intermediate,and near VA;and ease of handling were 4.1,3.4,3.6,3.5,and 3.4,respectively.The average discomfort scores for dryness,irritation,foreign body sensation,redness,fogging,and halo were 1.7,1.8,1.5,1.7,1.7,and 1.3,respectively.CONCLUSION:Far,intermediate,and near VA are improved in presbyopic patients with the multifocal corneoscleral lens compared to uncorrected baseline VA,without adverse ocular effects.This evidence supports the safety and effectiveness of presbyopia correction with multifocal corneoscleral lenses.

Differentiation of embryonic stem cells into corneal epithelium

Our project was to determine whether embryonic stem (ES) cells could be induced to differentiate into corneal epithelia by superficial corneoscleral limbal stroma. To achieve this goal, ES-GFP cell line D3 was pre-induced by retinoic acid (RA). The pre-induced cells were seeded on deepithelialized superficial corneoscleral slices (SCSS) to form a monolayer, and di-vided into three groups. Group 1 was cultured and passaged in vitro for direct detection. Group 2 was exposed to air-liquid interfaces for 10 days and implanted into the subcutaneous layer of nude mice for 2 weeks for further induction in vivo. Group 3 was cultured in vitro without any in-ducing factors for control. There were no teratomas found in nude mice which were implanted with differentiated ES cells after two weeks. The differentiated cells showed an appearance of epithelia both in vitro and in vivo. Expression of CK3, P63 and PCNA was detected by immuno-histochemical staining in the differentiated cells in group 1 and 2. Microvillis and zonula oc-cludens were observed on the surface of the differentiated cells under an electron microscope. In the control group, ES cells differentiated freely without any inducing factors. Most cells were shed and formed a neuronal dendrite-like structure, and a minority of cells appeared polymorphic. These results demonstrate that ES cells can differentiate into corneal epithelia on the surface of SCSS under the controlled condition. Differentiated ES cells could be used as epithelial seeding cells for the reconstruction of ocular surface and corneal tissue engineering in the future.