Biocompatibility of light responsive materials prepared for accommodative intraocular lenses manufacturing

AIM:To investigate the biocompatibility and bacterial adhesion properties of light responsive materials(LRM)and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular lenses(AIOLs).METHODS:Employing fundamental experimental research techniques,LRM with human lens epithelial cells(hLECs)and human retinal pigment epithelium cells(ARPE-19 cells)were co-cultured.Commercially available intraocular lenses(IOLs)were used as controls to perform cell counting kit-8(CCK-8),cell staining under varying light intensities,cell adhesion and bacterial adhesion experiments.RESULTS:LRM exhibited a stronger inhibitory effect on the proliferation of ARPE19 cells than commercially available IOLs when co-cultured with the undiluted extract for 96h(P<0.05).Under other culturing conditions,the effects on the proliferation of hLECs and ARPE-19 cells were not significantly different between the two materials.Under the influence of light irradiation at intensities of 200 and 300 mW/cm^(2),LRM demonstrated a markedly higher inhibitory effect on the survival of hLECs compared to commercially available IOLs(P<0.0001).They also showed a stronger suppressive effect on the survival rate of ARPE-19 cells,with significant differences observed at 200 mW/cm^(2)(P<0.001)and extremely significant differences at 300 mW/cm^(2)(P<0.0001).Additionally,compared to commercially available IOLs,LRM had a higher number of cells adhering to their surface(P<0.05),as well as a significantly greater number of adherent bacterium(P<0.0001).CONCLUSION:LRM,characterized by their excellent non-contact tunable deformability and low cytotoxicity to ocular tissues,show considerable potential for use in the fabrication of AIOLs.These materials demonstrate strong cell adhesion;however,during photothermal conversion processes involving shape deformation under various light intensities,the resultant temperature rise may harm surrounding cells.These factors suggest that while the material plays a positive role in reducing the incidence of posterior capsule opacification(PCO),it also poses potential risks for retinal damage.Additionally,the strong bacterial adhesion of these materials indicates an increased risk of endophthalmitis.

Encouraging Visual Outcome of a New Accommodative Intraocular Lens: A Retrospective Long-Term Study with a Mean Follow-Up of 5.3 Years

Purpose: To assess the visual outcome after implantation of the new Hydrophylic IOL type 41 B/G accommodating intraocular lens (AIOL). Methods: The presented lens was implanted during cataract surgery. All patients were offered follow-ups, allowing two postoperative measurements to be performed at 3 months and between 2020 and 2021. The mean time between lens implantation and last follow-up was 5.3 years (min. 1 year, max. 10 years). Excluded were patients with age-related macular degeneration or amblyopia. Patients with a foreign lens implanted into the second eye were included in a separate control group. Corrected distance (CDVA) and uncorrected distance visual acuity (UDVA) at 5 m, and corrected near (CNVA) and uncorrected near visual acuity (UNVA) at 40 cm were assessed. Furthermore, the postoperative spherical equivalent (SE), the dependence on spectacles and the occurrence of optical phenomena were evaluated. Results: The final study cohort consists of 65 patients with 119 implanted AIOLs. Significantly better visual results were obtained in both postoperative follow-ups compared with the preoperative results. The mean values of the last follow-up for the UNVA, CNVA, UDVA, and CDVA were 0.107 ± 0.10;0.039 ± 0.08;0.097 ± 0.11;and 0.040 ± 0.09 logMAR, respectively. Visual outcomes remained on a high level for up to 10 years and showed significantly better results compared to the control group. Postoperative SE was significantly improved. Nearly 70% of patients were no longer dependent on glasses. Furthermore, the occurrence of disturbing optical phenomena was denied by all patients. Conclusion: The results of this AIOL are particularly promising, especially since gratifying visual results could still be measured 10 years after implantation.

Vision, subjective accommodation and lens mobility after TetraFlex accommodative intraocular lens implantation

Background The TetraFlex accommodating intraocular lens （IOL） was designed to supply the patients both satisfied far and near vision after cataract surgery.So we need to evaluate the safety, distance and near visual acuity, subjective accommodation and IOL mobility with the TetraFlex accommodating IOL implantation.Methods Fifty eyes of 42 study-eligible cataract patients, who gave informed consent at a single eye clinic in China over a 10-month period, underwent phacoemulsification with TetraFlex IOL implantation.At three months postoperation,uncorrected visual acuities （UCVA）, best corrected visual acuities （BCVA）, distance-corrected near visual acuities （DCNVA）, subjective accommodation using the defocus method, and pilocarpine-induced IOL mobility were measured.Results No postoperative complications were noted in the study.Three months postoperation UCVA and BCVA were 20/40 or bettter in 82% （41/50） and 92% （46/50） of eyes, respectively; 66% （33/50） of the eyes had DCNVA of Jager （J） 4or better at 3 months.In addition, the mean subjective accommodation was （0.94±0.61） diopters （D） （range from 0.50 to 1.50 D） and pilocarpine-induced IOL mobility was （337±124） μm （range from 121 to 501 μm） with the TetraFlex.High relationship （r2=0.901, P 〈0.01） was found between these two measurements.Conclusion Implantation of the TetraFlex is safe and leads to excellent uncorrected distance vision and good uncorrected near vision.

Accommodative intraocular lenses:where are we and where we are going

Presbyopia still remains the last frontier of refractive surgery.Its surgical management is under constant evolution due to the limitations that exist today with respect to its management,which is probably in relation with the multifactorial basis in which presbyopia is clinically developed in the human.Until currently,virtually all surgical techniques that have been proposed for its correction are based on the induction of pseudoaccommodation in the presbyopic eye,including multifocality.However,the real restoration of accommodation is more complex,and it has been tried by the use of different,so called,“accommodative”pseudophakic intraocular lenses(AIOL).Overall,the reported results with these lenses by independent authors have been modest in relation with the restoration of the accommodative power of the eye and these modest benefits are usually lost with time due to the long term changes in the capsular bag.This fact made these lenses to be almost abandoned in the last few years,but there are currently other AIOL models being used with innovative mechanisms of action and different anatomical support outside the capsular bag that offer encouraging preliminary results that could bring a new potential of application to these types of lenses.In this article,we will update the modern refractive surgeon about the fundamentals and provide updated information about the outcomes of AIOLs by reviewing the concept of accommodation,the different attempts that have been accomplished in the past,their demonstrated published results in human clinical trials,and the future alternatives that may arrive in the near future.

Clinical application of accommodating intraocular lens

The present review describes recent advances in application of accommodating intraocular lenses （AIOLs）. Standard monofocal intraocular lenses （MIOLs） only correct distance vision, while AIOLs are designed to allow both good distance vision and near vision, which is achieved through the contraction and relaxation of ciliary muscles by providing transformation of the axial movement or curvature of the lens. Thus, AIOLs may be a better choice for those patients who demand a higher level of visual performance. Since techniques to analyze the performance of AIOLs have not been standardized, and there is a variety of both subjective and objective methods, it is hard to measure the performance of these intraocular lenses. By evaluating advantages and disadvantages of various AIOLs, and introducing techniques for measurement the performance postoperative, this paper can provide some relative information on choosing the type of AIOLs in the clinic.

The effects of premium intraocular lenses on presbyopia treatments

Background:Presbyopia has become a global disease affecting the world's aging population.Among various treatments,cataract extraction and intraocular lens(IOL)implantation have become the most popular and common methods of presbyopia correction.During the twentieth century,IOLs have underwent significant innovation and advancements to meet the patients'high demands for functional vision at all distances.Main Text:To meet the increasing needs for excellent near and intermediate vision for daily activities,some premium IOLs with more than one focus have been developed,for example,the refractive MfIOLs,diffractive MfIOLs,extended depth of field(EDOF)IOLs,and accommodating IOLs(AIOLs)were introduced to meet this need.In addition,the add-on MfIOLs have been explored as promising supplementary IOLs for pseudophakic presbyopia.When selecting the MfIOLs,the IOLs'features,patients’characteristics,preoperative eye conditions,and treatment expectations should be considered.Conclusions:In this review,we focus on the multifocal IOLs(MfIOLs)commonly used for presbyopia correction and systematically summarized their optical designs and clinical outcomes.More evidence-based studies are required to provide guidelines for MfIOL selection,provide maximum visual benefits,and develop personalized visual solutions in the future.