Light-adjustable Intraocular Lens Research Articles

Research advances on light-adjustable intraocular lens

Refractive error is a key determinant of visual acuity post-cataract surgery. Traditional methods for addressing refractive errors have been invasive, posing the risk of permanent surgical complications. Thus, the pursuit of non-invasive techniques for correcting refractive errors after cataract surgery is of significant clinical importance. Recently, a novel class of intraocular lenses (IOL), termed light-adjustable IOL, has emerged as a potential solution for refining refractive outcomes. These IOL possess the unique ability to alter their dioptric power in vitro through exposure to specific wavelengths of light, facilitating a non-invasive approach to refractive error correction. The landscape of light-adjustable IOL is diverse, encompassing ultraviolet light-adjustable IOL, novel nitinol-based thermomechanically adjustable IOL, IOL with refractive index changes induced by femtosecond lasers, and IOL utilizing two-photon effects for dioptric adjustment. This review article aims to summarize the advancements in light-adjustable lenses, providing insights and references for ongoing research and clinical practice in this field.

Panuveitis after ultraviolet light treatments for light adjustable intraocular lens.

To resport a case of panuveitis after light adjustable intraocular lens (LAL) implantation and ultraviolet (UV) light treatment. Case report. A 68-year-old woman with a history of herpes zoster without ocular involvement presented with panuveitis in her right eye two weeks after a UV light lock-in treatment for a recently implanted LAL. An infectious and inflammatory workup was only notable for positive HSV-1 and VZV IgG, but the patient did not have any history of ocular HSV or VZV. Over the course of five months, the panuveitis resolved completely with topical steroids and the patient had a good visual outcome. Though causality cannot be established in this case, physicians should be aware of the possibility of uveitis after UV light treatments. Extra caution should be observed in patients with history of herpetic disease.

Explantation of a light-adjustable intraocular lens: case report with laboratorial analyses

Introduction: A case in which a light-adjustable lens (LAL) underwent explantation and extensive laboratory analyses is reported. Patient and Clinical Findings: A 61-year-old man underwent uneventful cataract surgery with in-the-bag implantation of a first-generation LAL in the right eye. Examination on the second postoperative day revealed limbus-to-limbus corneal edema, moderate anterior chamber cells, and a mid-dilated, minimally responsive pupil, suggesting toxic anterior segment syndrome (TASS). Diagnosis, Intervention, and Outcomes: Endothelial keratoplasty was performed 2 months after LAL implantation. The patient reported noncompliance with required UV-protective eyewear, and an attempted light adjustment confirmed macromer reserve depletion, likely secondary to ambient UV contamination. Gross and microscopic examinations of the explanted LAL showed a decentered round elevation on the optic. The light transmittance (%T) curve was normal, with 95.9%T on average in the visible spectrum. Optical coherence tomography revealed irregular curvatures of the anterior and posterior optic surfaces. Wavefront analysis displayed aberrations and large power variations, which corresponded to decreased focus and contrast through the optic. Conclusions: To the authors' knowledge, this is the first reported case of LAL implantation complicated by TASS, leading to a prolonged clinical course and nonadherence to proprietary UV-protective spectacles. Extensive laboratory analyses of the explanted LAL demonstrated findings that can be expected with uncontrolled polymerization of the LAL.

Comparing Visual Outcomes of Light Adjustable Intraocular Lenses in Patients With and Without Prior History of Corneal Refractive Surgery

To assess visual outcomes of light adjustable intraocular lens (LAL; Calhoun Vision, Inc) implantation after cataract extraction in patients with a history of corneal refractive surgery. The records of patients who received LALs with and without a history of corneal refractive surgery were retrospectively reviewed. Data for 51 eyes (30 patients) with a history of corneal refractive surgery and 52 eyes (44 patients) without refractive surgery were analyzed. A total of 36 eyes of patients with and 43 eyes of patients without a history of corneal refractive surgery had 12-month follow-up data available. The primary outcomes evaluated were uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA). At 12 months, 31% of eyes with a history of corneal refractive surgery had a UDVA of 20/20 or better and 97% of eyes were 20/40 or better. In contrast, 63% of patients with no history of corneal refractive surgery had 20/20 UDVA or better at 12 months and 100% were 20/40 or better. Of patients with a history of corneal refractive surgery, 55% and 83% of eyes at 12 months were within ±0.50 and ±1.00 diopters, respectively, of the target refraction compared to 89% and 96% of eyes without a history of corneal refractive surgery. LALs are a promising platform for achieving excellent visual outcomes following cataract surgery. Patients with a prior history of corneal refractive surgery can achieve excellent visual outcomes with the LAL. However, this study found that patients with a history of corneal refractive surgery demonstrated less predictable visual acuity outcomes when compared to patients without a history of corneal refractive surgery. [J Refract Surg. 2023;39(5):311-318.].

Light Adjustable Intraocular Lens for Cataract Surgery After Radial Keratotomy

To describe a case of light adjustable lens implantation after radial keratotomy. A patient with a 30-year history of radial keratotomy subsequently underwent phacoemulsification with implantation of intraocular light adjustable lenses. Serial refractions were performed at varying hours of the day postoperatively and were repeated for 3 months. The light adjustable lenses were adjusted twice, and the refractive power of the implant was eventually locked. The patient was able to achieve uncorrected distance visual acuity of 20/25 in both eyes, improving from 20/125 in the right eye and 20/80 in the left eye, with no surgical complications. The authors report the first case of light adjustable lens implantation after radial keratotomy, which has yielded promising results for mitigating intraocular lens miscalculations after radial keratotomy. [J Refract Surg. 2020;36(12):852-854.].

Long-term follow-up and clinical evaluation of the light-adjustable intraocular lens implanted after cataract removal: 7-year results.

To determine the long-term safety and effectiveness of a light-adjustable intraocular lens (LAL) over a period that is longer than reported in the literature at the time of the study. University Eye Hospital, Bochum, Germany. Noninterventional observation. In 445 patients, cataract surgery with LAL implantation was performed between April 2008 and December 2012. It was possible to contact 171 of these patients or their relatives through letter or telephone; 61 patients (103 eyes) agreed to participate in the long-term study and were examined. The mean time between the lock-in (final light treatment) and long-term visit was 7.2 years; 61 patients were included and examined. Corrected and uncorrected distance visual acuity was and remained good (n = 93). The refractive outcome was stable with minimal deviation. There were no significant changes in corneal thickness. In 2 patients, there were slight opacities of the IOL material without impact on visual acuity. Other eye diseases were within the normal range of the patients' age. Seven years after implantation and refractive adjustment, eyes with an LAL had stable refraction, good visual acuity, and no IOL-associated pathologies. The findings suggest that LAL technology is a safe and efficient method to achieve good visual results without long-term complications.

Aktueller Stand „light-adjustable lens“

The light-adjustable intraocular lens offers the possibility to correct postoperative residual refractive errors in a non-invasive way. After implantation and healing, a fine-tuning of the refractive power can be performed using ultraviolet light based on the individual requirements of each patient. Up to 2 diopters in sphere, as well as cylinder, can be adjusted in one step. This technology received CE market approval in 2007. This review article summarises published prospective studies on clinical evaluations of the effectiveness, safety and long-term refractive stability of this innovative technique. Moreover, a critical statement about limitations and perspectives will be given and future options will be discussed. For safety reasons, following application of the UV-light during refractive adjustments, examinations of endothelial cell count changes and measurements of corneal thickness have been monitored for 12 months following treatment. Further studies have been performed to evaluate the refractive stability over an 18-month period with a patient population that included average as well as biometrically short and long eyes. An analysis of postoperative refractive data led to optimised constants for preoperative IOL power calculation enabling the surgeon to further enhance visual outcomes with the IOL by using additional nomograms for customised correction of presbyopia, multifocality and increasing depth of focus with individual corrections of asphericity.

Light-adjustable intraocular lens in post-LASIK and post-traumatic cataract patient

The case illustrates the use of a light-adjustable intraocular lens (IOL) in a patient who had had refractive surgery and developed blunt trauma with resultant flap damage and traumatic cataract. Consistent with early reports of the light adjustable IOL, which show positive results in non-LASIK eyes, this case suggests that the light-adjustable IOL may have similar benefits in the post-LASIK eye and other complex situations.

Lichtadjustierbare Linse

The aim of this study was a prospective evaluation of new algorithms for the treatment of presbyopia using a light-adjustable intraocular lens (LAL). A total of 15 patients scheduled for routine cataract surgery were included in the study. Following cataract removal a LAL (CalhounVision, Pasadena, CA) was implanted. At approximately 2 weeks after implantation the IOL was adjusted to correct any residual refractive error (sphere and cylinder) followed by the creation of a customized near add (CNA) that was based on the individual patient pupil size in one eye. The fellow eye was corrected for emmetropia. A final lock-in treatment was then performed. There were no complications observed during the surgery or power adjustments. All patients demonstrated an improvement in near vision (0.97 ± 0.18) and distance vision (0.78 ± 0.18) with good intermediate vision (0.92 ± 0.12) months after the final lock-in. This preliminary study showed that the creation of a CNA based on the individual patient's pupil size, provided patients with a good range of near, intermediate and distance vision following implantation of the LAL.

Evaluation of corneal endothelial cell loss and corneal thickness after cataract removal with light-adjustable intraocular lens implantation: 12-month follow-up

To determine quantitative changes in endothelial cell loss and corneal thickness in patients having cataract surgery and implantation of a light-adjustable intraocular lens (IOL) to correct residual postoperative refractive errors by application of a spatially profiled near-ultraviolet (UV) light. Ruhr University Eye Clinic, Bochum, Germany. Cohort study. The light-adjustable IOLs were implanted after phacoemulsification cataract surgery and treated with spatial-intensity-profiled UV light at 365 nm to induce a targeted refractive change. Once the desired correction was achieved, the light-adjustable IOL was treated again to lock-in the lens power. Noncontact computer-assisted endothelial cell microscopy and corneal pachymetry were performed before surgery; after surgery before adjustment; before lock-in; and 1, 3, 6, and 12 months after final lock-in. One hundred twenty-two eyes were evaluated 12 months after lock-in. The mean cumulative UV light dose at the cornea was 61.47 J/cm(2) ± 2.37 (SD). The mean endothelial cell loss was 6.91% ± 3.66% 2 weeks after surgery before adjustment and 6.57% ± 3.81% 12 months after lock-in. The mean relative change in corneal thickness from preoperatively was 6.18% ± 3.97% 2 weeks postoperatively and -0.64% ± 1.88% 12 months after lock-in. Endothelial cell loss and corneal thickness change 12 months after lock-in agreed well with those reported in the literature after phacoemulsification with IOL implantation. The UV light exposure for adjustment and lock-in procedures did not add to the endothelial damage caused by the cataract surgery.

Optimized constants for an ultraviolet light-adjustable intraocular lens

To determine the accuracy of intraocular lens (IOL) power calculations and to suggest adjusted constants for implantation of ultraviolet light-adjustable IOLs. Center for Vision Science, Ruhr University Eye Clinic, Bochum, Germany. Cohort study. Eyes with a visually significant cataract that had phacoemulsification with implantation of a light-adjustable IOL were evaluated. IOLMaster measurements were performed before phacoemulsification and IOL implantation and 4 weeks after surgery before the first adjustment of the IOL. The difference in the expected refraction and estimation error was studied. The study evaluated 125 eyes. Using the surgical constants provided by the manufacturer of the light-adjustable IOL, the SRK/T formula gave a more hyperopic refraction than the Hoffer Q and Holladay 1 formulas. The mean error of prediction was 0.93 diopter (D) ± 0.69 (SD), 0.91 ± 0.63 D, and 0.86 ± 0.65 D, respectively. The corresponding mean absolute error of prediction was 0.98 ± 0.61 D, 0.93 ± 0.61 D, and 0.90 ± 0.59 D, respectively. With optimized constants for the formulas, the mean error of prediction was 0.00 ± 0.63 D for Hoffer Q, 0.00 ± 0.64 D for Holladay 1, and 0.00 ± 0.66 D for SRK/T. The expected refraction after phacoemulsification and implantation of a light-adjustable IOL toward the hyperopic side of the desired refraction could be considered when using the optimized constants for all formulas.

Clinical Evaluation of an Ultraviolet Light Adjustable Intraocular Lens Implanted after Cataract Removal: Eighteen Months Follow-up

To determine the effectiveness of a light-adjustable intraocular lens (LAL) that can be adjusted postoperatively using ultraviolet (UV) irradiation. A prospective, nonrandomized clinical trial was conducted at Center for Vision Science, Ruhr University Eye Clinic, in Bochum, Germany. We included 122 eyes of 91 patients with significant cataract. All patients had a visually significant cataract and were willing to volunteer for the trial. Participants underwent small-incision phacoemulsification followed by implantation of a LAL and were treated with a spatially profiled UV light delivered by a digital light delivery device to induce a targeted spherical and cylindrical refractive change postoperatively. Once the desired correction was achieved, the LAL was treated again to lock in the lens power. Distance visual acuity and manifest refraction was determined with follow-up time to determine the achieved refractive corrections and their stability. We measured uncorrected visual acuity and best corrected visual acuity achieved versus targeted refractive outcome and refractive stability with a follow-up time of 18 months. Residual postoperative refractive errors of 0.96 ± 0.85 diopters (D) in sphere and -0.98 ± 0.50 D in cylinder were corrected and stable over a follow-up time of 18 months. Final refraction achieved was 0.03 ± 0.17 D in spherical equivalent refraction. Residual spherocylindrical errors up to 2.25 D in sphere and -2.75D in cylinder were successfully corrected with precision. The LAL technology has the potential individually to correct postoperative refractive errors precisely. The achieved refractive corrections are stable for up to 18 months. The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Combined Correction of Axial Hyperopia and Astigmatism Using the Light Adjustable Intraocular Lens

To determine whether residual spherical and cylindrical errors could be corrected postoperatively using spatially profiled UV light irradiation in patients with axial hyperopia undergoing cataract surgery and implantation of a light adjustable, silicone intraocular lens (LAL). We conducted a prospective, nonrandomized clinical trial. The LALs were implanted in eyes with axial lengths <22.20 mm and were treated with a spatial intensity profile delivered by a digital light delivery device to induce a targeted spherical and cylindrical refractive change postoperatively. Once the desired correction was achieved, the LAL was treated again to lock-in the lens power. We studied 15 eyes of 15 patients with axial hyperopia. The manifest refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BCVA) were determined with follow-up time of 12 months to determine the achieved refractive corrections and their stability. We measured UCVA, BCVA, achieved versus targeted refractive outcome, and refractive stability with a follow-up time of 12 months. Of 15 eyes, 14 (93%) achieved ± 0.5 diopters (D), and 10 (67%) were within ± 0.25 D of the targeted refractive adjustment up to 12 months postoperative follow-up. Only 1 treated eye showed a change of 0.38 D in manifest spherical equivalent refraction, the remaining 14 eyes showed <0.25 D change between 1 month post lock-in, and at the 3-, 6-, and 12-month postoperative visits. The light-adjustable lens is a promising technology with the potential to reduce the rate of postoperative refractive surprises up to 2 D of spherical and cylindrical errors after cataract surgery. Postoperative refractive errors were successfully corrected with precision and significant improvement in UCVA and without compromising BCVA using the light-adjustable intraocular lens technology. The data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures.

Corneal endothelial safety after ultraviolet light treatment of the light-adjustable intraocular lens

To assess the safety to the corneal endothelium of ultraviolet (UV) light treatment to a light-adjustable intraocular lens (IOL). Codet Vision Institute, Tijuana, Mexico. Cohort study. The study evaluated consecutive patients scheduled for phacoemulsification cataract surgery with implantation of a light-adjustable IOL. Endothelial cell density (ECD), variation in the size of endothelial cells, and the percentage of hexagonal cells were determined centrally with a specular microscope preoperatively, 1 week postoperatively (before UV treatment), and 6 months postoperatively. Two adjustments and 2 lock-in procedures were performed with a light-delivery system between 2 weeks and 4 weeks postoperatively. The study enrolled 10 patients. Specular microscopy showed a mean ECD of 2344 cells/mm(2) preoperatively. The mean overall central ECD was 2047 cells/mm(2) 1 week postoperatively and 2130 cells/mm(2) at 6 months, representing an endothelial cell loss of 12.6% and 9.1%, respectively, from preoperative values. There was no statistically significant difference in the coefficient of variation or percentage of hexagonal cells at either postoperative evaluation. The endothelial cell loss at 6 months correlated well with previous reports of endothelial damage after phacoemulsification with IOL implantation. The light-adjustable IOL irradiation protocol for adjustment and lock-in procedures did not seem to add to the endothelial damage caused by the cataract surgery, indicating the protocol is safe to the corneal endothelium.

Combined correction of sphere and astigmatism using the light-adjustable intraocular lens in eyes with axial myopia

To determine the efficacy of light-adjustable intraocular lenses (IOL) in correcting residual spherical and cylindrical errors in patients with axial myopia. Center for Vision Science, Ruhr University Eye Clinic, Bochum, Germany. Prospective cohort study. Light-adjustable IOLs were implanted in eyes with axial myopia and treated with spatial irradiance profiles delivered by a digital light-delivery device to induce a target spherical and/or spherocylindrical refractive change. Once the desired correction was achieved, the power of the IOL was locked in (ie, photo locking). The manifest refraction, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity (CDVA) were determined 1, 6, and 12 months after lock-in to determine the achieved refractive corrections and their stability. Twelve months postoperatively, 20 (96%) of the 21 eyes studied were within ± 0.50 diopter (D) of the intended refractive outcome and 17 (81%) were within ± 0.25 D. One eye had a 0.325 D change in mean refractive spherical equivalent (MRSE). The change in MRSE in the other 20 eyes was less than 0.250 D between 1 month after lock-in and the 3-, 6-, and 12-month postoperative visits. The light-adjustable IOL reduced postoperative spherical and cylindrical errors of up to 2.00 D. Postoperative refractive errors were successfully corrected, and there was a significant improvement in UDVA with concomitant maintenance of CDVA. The achieved refractive change was stable after the adjustment and lock-in procedures.

Retinal safety of the irradiation delivered to light-adjustable intraocular lenses evaluated in a rabbit model

To evaluate the safety to the retina of a light-delivery device used to irradiate a light-adjustable intraocular lens (IOL) after implantation in a rabbit model. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. In this study, rabbits had phacoemulsification with implantation of an ultraviolet (UV)-filtering light-adjustable IOL (study IOL) in 1 eye and a custom-made silicone IOL without a UV filter (control IOL) in the opposite eye. The study IOLs were irradiated at 1.0, 2.0, 3.0, and 5.0 times the expected maximum UV irradiation doses and the control IOLs, at 0.3, 0.6, 1.0, and 2.0 times. One week after irradiation, slitlamp and fundus (indirect ophthalmoscopy) examinations were performed. The rabbits were then humanely killed and their eyes enucleated and processed for histopathology. The 16 eyes with the study IOL (with UV filter) showed no signs of corneal, anterior segment, or retinal toxicity on histopathologic evaluation. The 16 eyes with the control IOL (no UV filter) also showed no signs of corneal or anterior segment toxicity; however, 3 eyes receiving the higher radiation doses had focal areas of retinal damage consistent with laser burn. Pigmented rabbit eyes with a light-adjustable IOL with a UV filter showed no signs of retina toxicity after near-UV light exposure up to 5 times the expected maximum treatment dosage. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Adjustierung von sphärozylindrischen Refraktionsfehlern bei hyperopen Augen: 6 Monatsergebnisse nach Kataraktchirurgie und Implantation einer lichtadjustierbaren Intraokularlinse

The aim of this study was to determine whether residual spherical and cylindrical errors could be corrected postoperatively in a non-invasive manner using ultraviolet irradiation in patients with axial hyperopia undergoing cataract surgery and implantation of a light-adjustable lens, silicone intraocular lens (LAL) (Calhoun Vision, Pasadena, CA). In a prospective, non-randomised clinical trial at Center for Vision Science, Ruhr University Eye Clinic, Bochum, Germany, 15 eyes of 15 patients with axial hyperopia (less than 22.2 mm) were studied. The manifest refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA) were determined with a follow-up time of six months to determine the achieved refractive corrections and their stability. The adjustment and lock-in procedures were well tolerated by patients. Preoperative refraction was in mean + 2.56 D as spherical equivalent, postoperative before adjustment + 1.01 D, one month after lock-in procedure + 0.03 D, after 3 months + 0.12 D and after 6 months 0.0 D (± 0.21 D). 6 months after lock-in all patients reached an uncorrected visual acuity of 20/30 or better, 10 of 15 patients reached 20/25 and 1 patient 20/20. The data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures. Postoperative refractive errors were successfully corrected with precision and significant improvement in UCVA and without compromising BSCVA using the light adjustable intraocular lens technology. Our data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures. The light-adjustable lens is a promising technology with the potential to eliminate postoperative refractive surprises of up to 2 diopters of refractive and cylindrical error following cataract surgery.

Clinical Results With the Light Adjustable Intraocular Lens After Cataract Surgery

The accuracy of intraocular lens (IOL) calculation is limited by the variation of the measurement of corneal power, axial length, anterior chamber depth, and effective postoperative lens position. Therefore, IOL predictability is limited. The aim of this study was to evaluate the performance of the novel light adjustable lens (LAL, Calhoun Vision). Ten eyes with cataracts (seven patients) were included. After standard phacoemulsification, the LAL was implanted. Two to 3 weeks after surgery, all IOL adjustments had been completed. Preoperatively, pre-adjustment, pre-lock-in, and 1 month post-lock-in, a full ophthalmic examination including objective (autorefraction) and subjective refraction (ie, manifest uncorrected visual acuity [UCVA] and manifest best spectacle-corrected visual acuity [BSCVA]) and topography were performed. All cataract surgeries were performed with no complications. Two weeks after surgery, the mean refraction was +0.78+/-0.79 diopters (D). After adjustment and lock-in, the refraction was -0.07+/-0.21 D. In 4 of 10 eyes, second adjustments were necessary. One month after surgery, all patients were within +/-0.50 D of the intended refraction. Preoperatively, the cylinder was 0.88+/-0.77 D, but was reduced after adjustments to 0.15+/-0.20 D. Mean UCVA was 1.02, and all eyes gained at least two lines on the Snellen visual acuity test (ie, BSCVA) after surgery. The LAL is a new IOL with the ability to correct up to 2.00 D of sphere and cylinder after implantation. Our first clinical results are promising and indicate effective safety and stability.

Correction of Residual Hyperopia After Cataract Surgery Using the Light Adjustable Intraocular Lens Technology

Correction of Residual Hyperopia After Cataract Surgery Using the Light Adjustable Intraocular Lens Technology

Correction of Residual Hyperopia After Cataract Surgery Using the Light Adjustable Intraocular Lens Technology

To determine whether residual hyperopia could be corrected postoperatively using the light adjustable lens technology in patients undergoing cataract surgery and light adjustable lens implantation. Prospective, nonrandomized clinical trial. Fourteen eyes of 14 patients were studied. The manifest refraction, uncorrected visual acuity (UCVA), and best-corrected visual acuity (BCVA) were determined with follow-up time to determine the achieved refractive corrections and their stability. Of 14 eyes, 13 eyes (92.9%) achieved +/- 0.25 diopters (D) of the target refraction at one day post lock-in, with 100% of the eyes achieving the targeted refractive adjustment within 0.5 D or better up to six months postoperative follow-up. All eyes treated show no change in manifest spherical refraction >0.25 D between one day post lock-in, and three and six months postoperative visits. The data demonstrate the stability of the achieved refractive change after the adjustment and lock-in procedures. The mean rate of change was 0.006 D per month, which is six times more stable than that of refractive procedures. Residual hyperopia errors in the range of +0.25 to +2.0 D were successfully corrected with precision and significant improvement in UCVA and without compromising BCVA using the light adjustable intraocular lens technology.