Depth- and direction-dependent changes in solute transport following cross-linking with riboflavin and UVA light in ex vivo porcine cornea.

Diffusion is an important mechanism of transport for nutrients and drugs throughout the avascular corneal stroma. The purpose of this study was to investigate the depth- and direction-dependent changes in stromal transport properties and their relationship to changes in collagen structure following ultraviolet A (UVA)-riboflavin induced corneal collagen cross-linking (CXL). After cross-linking in ex vivo porcine eyes, fluorescence recovery after photobleaching (FRAP) was performed to measure fluorescein diffusion in the nasal-temporal (NT) and anterior-posterior (AP) directions at corneal depths of 100, 200, and 300 µm. Second harmonic generation (SHG) imaging was also performed at these three corneal depths to quantify fiber alignment. For additional confirmation, an electrical conductivity method was employed to quantify ion permeability in the AP direction in corneal buttons and immunohistochemistry (IHC) was used to image collagen structure. Cross-linked corneas were compared to a control treatment that received the riboflavin solution without UVA light (SHAM). The results of FRAP revealed that fluorescein diffusivity decreased from 23.39 ± 11.60 µm2/s in the SHAM group to 19.87 ± 10.10 µm2/s in the CXL group. This change was dependent on depth and direction: the decrease was more pronounced in the 100 µm depth (P = 0.0005) and AP direction (P = 0.001) when compared to the effect in deeper locations and in the NT direction, respectively. Conductivity experiments confirmed a decrease in solute transport in the AP direction (P < 0.0001). FRAP also detected diffusional anisotropy in the porcine cornea: the fluorescein diffusivity in the NT direction was higher than the diffusivity in the AP direction. This anisotropy was increased following CXL treatment. Both SHG and IHC revealed a qualitative decrease in collagen crimping following CXL. Analysis of SHG images revealed an increase in coherency in the anterior 200 µm of CXL treated corneas when compared to SHAM treated corneas (P < 0.01). In conclusion, CXL results in a decrease in stromal solute transport, and this decrease is concentrated in the most anterior region and AP direction. Solute transport in the porcine cornea is anisotropic, and an increase in anisotropy with CXL may be explained by a decrease in collagen crimping.

Redefining vision assessment.

PURPOSE OF REVIEW: This review outlines ophthalmic diagnostic systems, which objectively evaluates the human visual system and its potential beyond that of Snellen acuity. RECENT FINDINGS: Advances in ophthalmic diagnostic systems have allowed for a deeper understanding of the optical principles of the human eye and have created the opportunity to evolve our current standards of vision assessment beyond Snellen acuity charts. Definitive comparative and validation trials will continue to be necessary in order for these advanced diagnostics to gain more widespread acceptance in the specialty, in addition to providing the guidance on the specific indications and utilities. SUMMARY: Advancements in wavefront analysis, light scatter measurements, and adaptive optics technologies can provide greater insight into an individual optical system's potential and irregularities. Modalities that test for anterior corneal surface and whole eye aberrations, light scatter and contrast sensitivity can be an excellent educational tool for our patients to help them better understand their visual dysfunction and can prove useful for medical or surgical decision-making.

Dysfunctional tear syndrome: dry eye disease and associated tear film disorders - new strategies for diagnosis and treatment.

Dysfunctional tear syndrome (DTS) is a common and complex condition affecting the ocular surface. The health and normal functioning of the ocular surface is dependent on a stable and sufficient tear film. Clinician awareness of conditions affecting the ocular surface has increased in recent years because of expanded research and the publication of diagnosis and treatment guidelines pertaining to disorders resulting in DTS, including the Delphi panel treatment recommendations for DTS (2006), the International Dry Eye Workshop (DEWS) (2007), the Meibomian Gland Dysfunction (MGD) Workshop (2011), and the updated Preferred Practice Pattern guidelines from the American Academy of Ophthalmology pertaining to dry eye and blepharitis (2013). Since the publication of the existing guidelines, new diagnostic techniques and treatment options that provide an opportunity for better management of patients have become available. Clinicians are now able to access a wealth of information that can help them obtain a differential diagnosis and treatment approach for patients presenting with DTS. This review provides a practical and directed approach to the diagnosis and treatment of patients with DTS, emphasizing treatment that is tailored to the specific disease subtype as well as the severity of the condition.

Retrospective evaluation of the influence of pupil size on visual acuity after KAMRA inlay implantation.

PURPOSE: To investigate the influence of pupil size on visual acuity after KAMRA inlay (AcuFocus, Inc., Irvine, CA) implantation. METHODS: Five hundred eighty-four presbyopic eyes of 584 patients who underwent LASIK were evaluated. Uncorrected near visual acuity (UNVA), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and corrected near visual acuity (CNVA) were measured. Two groups were classified: small pupil (pupil diameter < 6 mm) and large pupil (pupil diameter ≥ 6 mm) for both mesopic (pupil diameter < 4 mm) and photopic (pupil diameter ≥ 4 mm) pupil size parameters. The follow-up period was 6 months. RESULTS: There were no significant differences in UNVA (P = .98) and CNVA (P = .16) between the mesopic pupil size groups; however, there were significant differences in UDVA (P = .023) and CDVA (P = .039). There was a weak correlation between pupil size and UDVA of the large mesopic pupil size group (rs = 0.129, P = .04). There were no significant differences in UNVA (P = .78), CNVA (P = .92), UDVA (P = .19), and CDVA (P = .60) for the photopic pupil size groups. CONCLUSIONS: Pupil size does not have an influence on the resultant visual acuity after KAMRA inlay implantation. No correlation was found between preoperative and postoperative pupil size and visual acuity for the mesopic pupil groups.

Outcomes of small aperture corneal inlay implantation in patients with pseudophakia.

PURPOSE: To evaluate the improvement in near visual acuity after KAMRA corneal inlay (AcuFocus, Inc., Irvine, CA) implantation in patients with pseudophakia. METHODS: A retrospective study analysis of patients with pseudophakia undergoing monocular corneal inlay implantation in the non-dominant eye was performed. The inlay was implanted monocularly in the non-dominant eye of patients. Manifest refractive spherical equivalent, uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, and corrected near visual acuity were evaluated. The follow-up period was 3 months. RESULTS: Thirteen eyes from 13 patients were evaluated. Four patients underwent LASIK for improved distance acuity at the time of inlay implantation. Mean uncorrected near visual acuity improved five lines (from J10 to J4) postoperatively. Mean uncorrected distance visual acuity, corrected distance visual acuity, and corrected near visual acuity remained stable and were 20/20, 20/16, and J1, respectively, before and after KAMRA implantation. Three eyes lost two lines and 1 eye lost one line of uncorrected distance visual acuity. Two eyes lost two lines and 1 eye lost 1 line of corrected distance visual acuity. Mean manifest refractive spherical equivalent changed before and after KAMRA implantation from -0.01 ± 1.07 diopters (D) (range: 2.25 to -1.88 D) to -1.12 ± 0.87 D (range: 0.25 to -2.75 D), respectively. CONCLUSIONS: Implantation of a small aperture corneal inlay improved uncorrected near visual acuity while maintaining uncorrected and corrected distance visual acuity in monofocal patients with pseudophakia.

Microkeratome versus femtosecond flaps: accuracy and complications.

PURPOSE OF REVIEW: To update the knowledge on differences between mechanical microkeratome and femtosecond flaps for laser in-situ keratomileusis (LASIK) in terms of accuracy and complications. RECENT FINDINGS: Corneal flaps created with the femtosecond laser present a more planar architecture and provide greater precision in flap diameter and thickness; a more uniform flap thickness across the flap diameter and it allows the surgeon to programme the angulation of the flap periphery. Femtosecond LASIK flaps are classically related to complications derived from a more intense inflammatory response, such as diffuse lamellar keratitis and transient light-sensitivity syndrome. Newer femtosecond models allow for much lower energy delivery to cut the flap, to the point the overall inflammatory response is not significantly different from the microkeratome. The incidence of complications such as epithelial defect and flap dislocations is higher with microkeratome flaps. SUMMARY: This review examines the accuracy and complications of flaps created with femtosecond and microkeratome. Both femtosecond and microkeratome are able to create accurate LASIK flaps. Femtosecond LASIK flaps represent significant improvement in morphology and predictability with implications for safety.

Tolerance to Induced Astigmatism With a Monofocal Intraocular Lens Designed to Extend the Depth of Focus.

PURPOSE: To determine tolerance to residual astigmatism and visual performance in eyes implanted with a monofocal intraocular lens (IOL) designed to extend the depth of focus (Tecnis Eyhance, DIB00; Johnson & Johnson Vision) compared to eyes implanted with a standard monofocal IOL (Tecnis ZCB00; Johnson & Johnson Vision). METHODS: This prospective, observational study enrolled consecutive patients who underwent routine cataract surgery and implantation of either the DIB00 (n = 20) or ZCB00 (n = 20) IOL. Astigmatic defocus was induced with a plus cylinder from +0.50 to +2.00 diopters (D) in 0.50-D steps for each astigmatic orientation (against-the-rule [ATR], with-the-rule [WTR], and oblique). Outcome measures included the comparison of mean visual acuity at each step of defocus, astigmatic defocus curves, and near and intermediate visual acuity. RESULTS: Eyes implanted with the DIB00 demonstrated greater astigmatic tolerance and were more likely to maintain 20/40 or better visual acuity with up to +2.00 D of induced ATR and oblique astigmatism than the ZCB00 IOLs. The DIB00 group showed 1.3 lines better visual acuity at 2.00 D of ATR astigmatic defocus and 1 line better than the ZCB00 group at 1.50 D of oblique astigmatic defocus. Although the distance visual acuity was comparable, near and intermediate visual acuities (both distance-corrected and uncorrected) were better for the DIB00 IOL than for the standard ZCB00 IOL. CONCLUSIONS: The monofocal IOL designed to extend the depth of focus (DIB00 group) showed greater tolerance to induced astigmatism in ATR and oblique orientations and superior uncorrected and distance-corrected near and intermediate visual acuity than the standard monofocal IOL of the same IOL platform. [J Refract Surg. 2023;39(4):222-228.].

Impact of presbyopia treatment pilocarpine hydrochloride 1.25% on night-driving performance.

CLINICAL RELEVANCE: Patients prescribed pilocarpine ophthalmic solution are advised to be cautious when driving at night, but studies evaluating the effects of pilocarpine hydrochloride ophthalmic solution 1.25% (pilo), approved to treat presbyopia, on driving at night are lacking. BACKGROUND: This double-masked, crossover, phase 3b study evaluated night-driving performance with pilo or the placebo once daily. METHODS: Forty-three adults (40-55 years) with presbyopia impacting daily activities and mesopic, high-contrast, binocular distance-corrected near vision 6/12-6/30 were randomised to bilateral treatment with pilo followed by placebo or placebo followed by pilo (with a ≥7-day washout between interventions). Night-driving performance was evaluated at twilight at a closed-circuit course. Primary efficacy endpoint: overall composite night-driving performance Z score at the end of the 7-14-day intervention period, 1 hour post-instillation. Pilo was considered non-inferior if the lower limit of the 95% confidence interval (CI) for the least squares mean difference (LSMD, pilo minus placebo) was >-0.25. Other efficacy endpoints: individual components of the night-driving performance test (hazard avoidance rate; road sign recognition rate and distance; pedestrians recognition distance; overall driving and lane-keeping times) and night-driving experience questionnaire. Safety included treatment-emergent adverse events (TEAEs). RESULTS: The mean overall composite Z scores were -0.121 (pilo) and 0.118 (placebo). The LSMD (pilo minus placebo) was -0.224 (95% CI, -0.346, -0.103), with 3 of the 7 individual tasks being significantly better with the placebo. The questionnaire did not reveal significant differences between pilo and the placebo. There were no serious or severe TEAEs and no TEAE-related discontinuations. The most common ocular TEAEs were headache and visual impairment with pilo (both 27.9%), and dry eye (7.0%) with the placebo. CONCLUSION: The overall performance of night driving was inferior with pilo, compared with placebo. The study findings are consistent with the current class labelling and provide evidence to inform regulators and assist clinicians considering prescribing pilo to adults who seek treatment of presbyopia symptoms and drive at night.ClinicalTrials.gov identifier: NCT04837482.

Spectral-Domain OCT Lens Meridian Position as a Metric to Estimate Postoperative Anatomical Lens Position.

PURPOSE: To evaluate the prediction of postoperative anatomical lens position (ALP) using intraoperative spectral-domain optical coherence tomography (SD-OCT) lens anatomy metrics in patients who underwent femtosecond laser-assisted cataract surgery. METHODS: Intraoperative SD-OCT (Catalys; Johnson & Johnson Vision) and postoperative optical biometry (IOLMaster 700; Carl Zeiss Meditec AG) were used to assess anterior segment landmarks, including lens thickness, lens volume, anterior chamber depth, lens meridian position (LMP), and measured ALP. LMP was defined as the distance from the corneal epithelium to the lens equator, and ALP was defined as the distance from the corneal epithelium to the IOL surface. Eyes were divided into groups according to axial length (> 22.5 mm, 22.5 to 24.5 mm, and > 24.5 mm) and IOL type (Tecnis ZCB00 [Johnson & Johnson Vision]; AcrySof SN-60WF [Alcon Laboratories, Inc], or enVista MX60E [Bausch & Lomb]) to further analyze the correlation between LMP and ALP. Theoretical effective lens position was back-calculated using a specific formula. Primary outcome was correlation between postoperative measured ALP and LMP. RESULTS: A total of 97 eyes were included in this study. Linear regression analysis displayed a statistically significant correlation between intraoperative LMP and postoperative ALP (R2 = 0.522; P < .01). No statistically significant correlation was observed between LMP and lens thickness (R2 = 0.039; P = .06) or between ALP and lens thickness (R2 = 0.02; P = .992). The greatest predictor for ALP was LMP (ß = 0.766, P < .001; R2 = 0.523). CONCLUSIONS: Intraoperative SD-OCT-measured LMP correlated better than anterior chamber depth and axial length to postoperative ALP. Further studies are necessary to analyze the impact of preoperative or intraoperative LMP measurements on postoperative refractive outcomes. [J Refract Surg. 2023;39(3):165-170.].

Optimized Artificial Intelligence for Enhanced Ectasia Detection Using Scheimpflug-Based Corneal Tomography and Biomechanical Data.

PURPOSE: To optimize artificial intelligence (AI) algorithms to integrate Scheimpflug-based corneal tomography and biomechanics to enhance ectasia detection. DESIGN: Multicenter cross-sectional case-control retrospective study. METHODS: A total of 3886 unoperated eyes from 3412 patients had Pentacam and Corvis ST (Oculus Optikgeräte GmbH) examinations. The database included 1 eye randomly selected from 1680 normal patients (N) and from 1181 "bilateral" keratoconus (KC) patients, along with 551 normal topography eyes from patients with very asymmetric ectasia (VAE-NT), and their 474 unoperated ectatic (VAE-E) eyes. The current TBIv1 (tomographic-biomechanical index) was tested, and an optimized AI algorithm was developed for augmenting accuracy. RESULTS: The area under the receiver operating characteristic curve (AUC) of the TBIv1 for discriminating clinical ectasia (KC and VAE-E) was 0.999 (98.5% sensitivity; 98.6% specificity [cutoff: 0.5]), and for VAE-NT, 0.899 (76% sensitivity; 89.1% specificity [cutoff: 0.29]). A novel random forest algorithm (TBIv2), developed with 18 features in 156 trees using 10-fold cross-validation, had a significantly higher AUC (0.945; DeLong, P < .0001) for detecting VAE-NT (84.4% sensitivity and 90.1% specificity; cutoff: 0.43; DeLong, P < .0001) and a similar AUC for clinical ectasia (0.999; DeLong, P = .818; 98.7% sensitivity; 99.2% specificity [cutoff: 0.8]). Considering all cases, the TBIv2 had a higher AUC (0.985) than TBIv1 (0.974; DeLong, P < .0001). CONCLUSIONS: AI optimization to integrate Scheimpflug-based corneal tomography and biomechanical assessments augments accuracy for ectasia detection, characterizing ectasia susceptibility in the diverse VAE-NT group. Some patients with VAE may have true unilateral ectasia. Machine learning considering additional data, including epithelial thickness or other parameters from multimodal refractive imaging, will continuously enhance accuracy. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Management and outcomes of suction loss during LASIK flap creation with a femtosecond laser.

PURPOSE: To evaluate risk factors, management, and outcomes in patients who experienced suction loss during LASIK flap creation with a femtosecond laser (Intra-Lase FS 60, Abbott Medical Optics Inc). METHODS: Pre- and postoperative visual outcomes and refractions for 71 eyes of 70 patients after suction loss during flap creation with the IntraLase FS60 femtosecond laser were analyzed and studied. RESULTS: In patients requiring a second or third lamellar flap cut immediately after suction loss, 97.2% of eyes achieved uncorrected distance visual acuity of 0.00 logMAR (20/20) or better and 100% of eyes achieved corrected distance visual acuity of 0.00 logMAR (20/20) or better at most recent follow-up. CONCLUSIONS: Our study suggests that excellent visual outcomes can be achieved if an immediate lamellar recut is performed after suction loss with a femtosecond laser.

A contralateral, randomized comparison of optimized prolate ablation and conventional LASIK for myopia with the NIDEK excimer laser platform.

PURPOSE: To compare the refractive, visual acuity, topographic, and spherical aberration outcomes of LASIK using the Quest excimer laser platform with the optimized prolate ablation (OPA) profile (NIDEK Co Ltd) in one eye and conventional ablation profile in the fellow eye of the same patient. METHODS: Thirty-seven myopic patients underwent LASIK bilaterally, with one eye randomized to receive OPA ablation (-3.88±1.42 diopters [D], range: -1.53 to -7.50 D) and the fellow eye to receive conventional ablation (-3.89±1.37 D, range: -1.75 to -7.00 D). Independent and paired t tests were used for testing differences between groups at last postoperative follow-up (6 or 12 months). RESULTS: Postoperatively, 97% (32/33) of OPA eyes and 94% (31/33) of conventional eyes saw 20/20 or better without correction (P>.05). No eyes lost 2 or more lines of distance corrected visual acuity. Manifest refraction spherical equivalent was -0.16 D in the OPA group and -0.05 D in the conventional group (P>.05). Ocular spherical aberration was -0.003 µm in the OPA group and +0.102 µm in the conventional group (P<.05). Corneal asphericity was statistically lower after OPA (0.07±0.26) compared to conventional ablation (0.30±0.26) (P<.001). The mean programmed optical zone and achieved postoperative horizontal diameter of the effective optical zone were statistically significantly larger in the OPA group (P<.05). CONCLUSIONS: Postoperative visual acuity and refractive outcomes were similar between groups. Laser in situ keratomileusis using the OPA profile for the correction of myopia induced significantly less corneal and ocular spherical aberration, resulted in normal postoperative asphericity in 94% of eyes, and larger horizontal diameter of the effective optical zone compared to the conventional profile.

Ray-tracing Analysis of Accommodation and Pseudoaccommodation in Phakic and Pseudophakic Eyes.

PURPOSE: To compare objective measurements of accommodation and pseudoaccommodation in phakic and pseudo-phakic eyes using ray-tracing aberrometry. METHODS: Patients with normal and hyperprolate corneas (post-hyperopic laser in situ keratomileusis) who underwent cataract surgery from March 2018 to October 2019 at the Medical University of South Carolina were examined and received either a diffractive intraocular lens (IOL) with an echelette design (Tecnis ZXR00 Symfony; Johnson & Johnson Vision), a monofocal IOL with negative spherical aberration (Tecnis ZCB00; Johnson & Johnson Vision), or an aberration-free IOL (MX60E; Bausch & Lomb). The control groups consisted of young and presbyopic phakic patients. Ray-tracing wavefront analysis was performed 1 to 3 months postoperatively. Objective ray-tracing metrics of accommodation and pseudoaccommodation included the effective range of focus, sphere shift accommodation, and depth of focus. RESULTS: Sixty-two eyes received a Tecnis ZCB00, 39 a MX60E, and 43 a Tecnic ZXR00 Symfony IOL; furthermore, 20 young phakic eyes and 19 presbyopic eyes were included in this study. The effective range of focus and sphere shift accommodation in the young control group were statistically larger than in the presbyopic group (P = .005 and P < .001, respectively). There was no difference in effective range of focus, sphere shift accommodation, and pseudoaccommodations between the different IOL groups. The young control group had the highest visual Strehl optical transfer function for near and distant targets (0.64 ± 0.24 and 0.56 ± 0.19, respectively), whereas the aberration-free IOL in the MX60E hyperprolate cornea group presented the lowest visual Strehl optical transfer function value for near (0.49 ± 0.19). CONCLUSIONS: Ray-tracing aberrometry can objectively assess accommodative amplitude in phakic eyes and pseudoaccommodation (depth of focus) in pseudophakic eyes. [J Refract Surg. 2022;38(10):661-667.].

Safety and Efficacy of AGN-190584 in Individuals With Presbyopia: The GEMINI 1 Phase 3 Randomized Clinical Trial.

IMPORTANCE: AGN-190584 (Allergan, an AbbVie company) is an optimized topical formulation of pilocarpine hydrochloride, 1.25%, designed for managing presbyopia and enhanced with a proprietary vehicle. OBJECTIVE: To evaluate the efficacy and safety of pilocarpine hydrochloride, 1.25%, in individuals with presbyopia. DESIGN, SETTING, AND PARTICIPANTS: This vehicle-controlled, participant- and investigator-masked, randomized, phase 3 clinical study, GEMINI 1, enrolled individuals with presbyopia, aged 40 to 55 years, at 36 sites in the United States from December 21, 2018, to October 31, 2019. Analysis took place between February 2020 and December 2021. INTERVENTIONS: AGN-190584 or the AGN-190584 formulation vehicle was administered bilaterally, once daily for 30 days. MAIN OUTCOMES AND MEASURES: The proportion of participants with improvement of 3 or more lines in mesopic, high-contrast, binocular distance-corrected near visual acuity (DCNVA) at hours 3 and 6 on day 30 were the primary and key secondary efficacy end points, respectively. Safety measures included adverse events. RESULTS: Of 323 participants who were randomized, 235 (72.8%) were female and 292 (90.4%) were White. The mean (SD) age was 49.6 (3.5) years, and the baseline mean (SD) mesopic DCNVA was 29.2 (6.3) letters. A total of 163 individuals were randomized to AGN-190584 and 160 were randomized to vehicle. GEMINI 1 met its primary and key secondary efficacy end points. On day 30, hour 3, the percentage of participants with improvement of 3 or more lines in mesopic DCNVA was 30.7% (50 of 163) in the AGN-190584 group and 8.1% (13 of 160) in the vehicle group (difference, 22.5% [95% CI, 14.3%-30.8%]; adjusted P < .001). At hour 6, those percentages were 18.4% (30 of 163) and 8.8% (14 of 160), respectively (difference, 9.7% [95% CI, 2.3%-17.0%]; adjusted P = .01). At hour 8, the between-group difference in 3 or more lines of mesopic DCNVA gains was not statistically significant, but clinically relevant prespecified outcome measures demonstrated AGN-190584 superiority to vehicle in least-squares mean (SE) mesopic DCNVA change from baseline at hour 8 (5.4 [0.51] vs 3.6 [0.52] letters; P = .009) and photopic distance-corrected intermediate visual acuity at hour 8 (3.9 [0.44] vs 2.4 [0.45] letters; P = .01) and hour 10 (3.5 [0.46] vs 1.7 [0.47] letters; P = .004). No participants with mesopic DCNVA improvement of 3 or more lines at hour 3 had losses of more than 5 letters in mesopic, high-contrast, binocular-corrected distance visual acuity. The onset of effect was at 15 minutes. AGN-190584 demonstrated an acceptable safety and tolerability profile. CONCLUSIONS AND RELEVANCE: AGN-190584 demonstrated superiority over vehicle in mesopic DCNVA on day 30, hours 3 and 6, with an acceptable safety profile. AGN-190584 is a safe and efficacious topical therapy for presbyopia through 30 days. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03804268.

In Vitro and In-Eye Comparison of Commercial Pilocarpine Ophthalmic Solution and an Optimized, Reformulated Pilocarpine for Presbyopia Treatment.

INTRODUCTION: Pilocarpine hydrochloride (pilo) ophthalmic solution has traditionally been used for the treatment of glaucoma, with opportunities to improve the tolerability profile experienced by patients. Pilocarpine hydrochloride ophthalmic solution 1.25% (Vuity™, Allergan, an AbbVie company) was approved in late 2021 for the treatment of adults with presbyopia. This publication describes the properties of the optimized, proprietary vehicle of this new ophthalmic solution developed with the aim of improving tolerability upon instillation. METHODS: An in vitro method determined the time required for the pH of pilo 1.25% in the proprietary vehicle (Optimized Formulation) and a commercially available 1% pilo ophthalmic solution (Generic Formulation) to equilibrate with the pH of simulated tear fluid (STF). In a pilot study, five of the six screened participants received one drop of the Optimized Formulation in one eye and Generic Formulation in the other. Ocular discomfort and vision blur were evaluated for each eye just prior to and at multiple times after drop instillation using visual analog scales (VAS), and adverse events were assessed. RESULTS: The in vitro method showed that the Optimized Formulation achieved faster pH equilibration than the Generic Formulation. The pilot study revealed that the Optimized Formulation demonstrated less ocular discomfort, vision blur, and adverse events compared to the Generic. CONCLUSION: The in vitro and pilot study of the Optimized Formulation indicated that it rapidly equilibrates to the physiologic pH of the tear film, providing greater comfort and tolerability while also minimizing vision blur. Overall, the proprietary vehicle is expected to improve comfort, result in less vision blur, and provide a well-tolerated alternative method to deliver pilo for the treatment of presbyopia when compared to what is commercially available.

Correction of presbyopia with a small aperture corneal inlay.

PURPOSE: To assess the efficacy of a small aperture corneal inlay (KAMRA, AcuFocus Inc) to improve near vision in emmetropic presbyopes. METHODS: Prospective, nonrandomized, multicenter clinical trial in presbyopic emmetropes aged 45 to 60 years. A small corneal pocket or flap was created in the nondominant eye by femtosecond laser or mechanical microkeratome, and the inlay (N=507) placed on the stromal bed. Uncorrected visual acuity was measured for the implanted eye at near (40 cm), intermediate (80 cm), and distance (20 ft) using ETDRS charts with the Optec 6500 Vision Tester (Stereo Optical Inc) at the preoperative, and 1-, 3-, 6-, 9-, 12-, and 18-month postoperative examinations. Contrast sensitivity (CS) was measured with best distance correction in the implanted eye using the Optec system and FACT chart under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) conditions preoperatively and at 1-year follow-up. RESULTS: Mean patient age was 52.87±3.64 years. Monocular mean uncorrected near visual acuity was J8 (0.482±0.925 logMAR) preoperatively, J3 (0.185±0.848 logMAR) at 1 month (n=506, P<.0001), and J2 (0.139±0.851 logMAR) at 18 months (n=99, P<.0001). Mean uncorrected intermediate visual acuity was 20/35 (0.239±0.837 logMAR) preoperatively and 20/26 (0.139±0853 logMAR) at 18 months (P<.0001). Mean uncorrected distance visual acuity (UDVA) was 20/20 (0.011±0.890 logMAR) at 18 months. Photopic (P<.001) and mesopic (P<.0001) monocular contrast sensitivities were within the range of the normal population at 1 year. CONCLUSIONS: The KAMRA corneal inlay improved near visual acuity with minimal impact on UDVA or mesopic contrast sensitivity in the implanted eye.

Presbyopia Treatments by Mechanism of Action: A New Classification System Based on a Review of the Literature.

Presbyopia, a loss of accommodative ability associated with aging, is a significant cause of vision impairment globally. At the clinical level, it is a frustrating and difficult issue that negatively impacts patients' quality of life. Less appreciated is the fact that loss of accommodative ability and its current treatments methods may present safety concerns, for example, increasing the risk of falls. Therefore, a more complete understanding of treatment options with respect to how they relate to the natural ability of the eye is needed to improve decision making and to aid clinicians in individualizing treatment options. This article reviews the options for expanding functional through focus-a term coined to describe the ability of the eye to see at all distances with minimal latency-by how they vary the refractive power over time, across the visual field, between eyes, or across a range of distances.

Future Trends in Presbyopia Correction.

Presbyopia affects 1.8 billion people worldwide. This reduction in distance corrected near visual acuity impacts quality of life, which prompts patients to seek treatment. Presbyopia is an early manifestation of the "crystalline lens optical dysfunction through aging," or dysfunctional lens syndrome, and appropriate management of presbyopia is dependent on coexisting factors such as increased higher order aberrations, reduced contrast sensitivity, light scatter, and lenticular opacification. This review of published literature (PubMed and MEDLINE) is presented in narrative format and discusses medical and surgical treatments available to patients who experience presbyopia, while highlighting future therapies. Numerous strategies exist for the management of presbyopia. These strategies include pharmacological therapy, glasses and contact lenses, corneal, scleral, and lenticular procedures. This article discusses the role of several new and existing presbyopia treatments, as well as which patients are candidates for these novel therapies. Although no single treatment is ideal for all patients with presbyopia, new medical and surgical strategies increase the number of options available when addressing different stages of presbyopia and dysfunctional lens syndrome. [J Refract Surg. 2021;37(6 Suppl):S28-S34.].

Comparing conventional and wavefront-optimized LASIK for the treatment of hyperopia.

PURPOSE: To compare differences in visual outcomes and induced spherical aberration after conventional and wavefront-optimized LASIK for the treatment of hyperopia. METHODS: In a prospective, randomized, single-center clinical trial, 51 consecutive eyes underwent LASIK for the treatment of hyperopia. Eyes were divided between groups treated with conventional LASIK with the Alcon LADAR4000 excimer laser (n=25) and wavefront-optimized LASIK with the WaveLight ALLEGRETTO excimer laser (n=26). Refractive and visual outcomes, induced spherical aberrations, and contrast sensitivity were analyzed. RESULTS: On postoperative day 1, 20% of eyes treated with a conventional profile had uncorrected visual acuity (UCVA) of 20/20 or better compared to 65% of eyes receiving wavefront-optimized treatment (P=.0011). By 6 months, UCVA was 20/20 or better in 72% and 84% of the conventional and wavefront-optimized treatment groups, respectively (P=.3254). At 6 months, the manifest refraction spherical equivalent was -0.21+/-0.47 diopters (D) and 0.16+/-0.27 D (P=.6469) whereas the cylinder was -0.41+/-0.47 D and -0.17+/-0.27 D (P=.0332) for the conventional and wavefront-optimized treatment groups, respectively. Induced spherical aberration was -0.54+/-0.32 microm and -0.42+/-0.21 microm for the conventional and wavefront-optimized treatment groups, respectively (P=.1195). The respective change in mesopic and photopic area under the log contrast sensitivity function was -0.05+/-0.29 and -0.05+/-0.23 for the conventional treatment group and 0.08+/-0.39 and 0.08+/-0.41 for the wavefront-optimized treatment group (P=.1970). CONCLUSIONS: Wavefront-optimized (ALLEGRETTO) and conventional (LADAR4000) ablation predictably and safely correct low to moderate hyperopia. Wavefront-optimized ablation showed superior results with regards to rapid visual recovery and residual cylinder. Although not statistically significant, a trend towards less induced negative spherical aberrations and improved mesopic and photopic contrast sensitivity was noted with wavefront-optimized treatment.

Impact of a Chromatic Aberration-Correcting Intraocular Lens on Automated Refraction.

PURPOSE: To compare ray-tracing aberrometry, Hartmann-Shack wavefront analysis, automated refraction, and manifest refraction in patients with echelette diffractive intraocular lenses (IOLs) and patients with monofocal IOLs with negative spherical aberration. METHODS: Pseudophakic patients implanted with an echelette diffractive IOL (Tecnis ZXR00; Johnson & Johnson Vision) and a control group consisting of patients implanted with a negative spherical aberration monofocal IOL (Tecnis ZCBOO, Johnson & Johnson Vision) were included in this study. Ray-tracing aberrometry (iTrace; Tracey Technologies Corp.), Hartmann-Shack wavefront analysis (LADARWave; Alcon Laboratories, Inc.), automated refraction (Topcon KR-8800; Topcon Medical Systems, Inc.), and manifest refraction spherical equivalent were performed 1 to 3 months postoperatively. RESULTS: Thirty-two eyes implanted with a ZXR00 IOL and 30 eyes implanted with a ZCBOO IOL were enrolled in this study. The ZXR00 IOL group yielded more myopic results with automated refactions (-0.62 ± 0.41 diopters [D]), Hartmann-Shack wavefront analysis (-0.85 ± 0.40 D), and ray-tracing aberrometry (-0.45 ± 0.64 D), compared to manifest refraction (-0.12 ± 0.44 D) (P < .001). Hartmann-Shack wavefront analysis showed a statistically significant myopic shift (-0.39 ± 0.47 D) in the ZCBOO group compared to ray-tracing aberrometry, automated refraction, and manifest refraction spherical equivalent (-0.14 ± 0.56, -0.14 ± 0.50, and -0.06 ± 0.44 D, respectively; P < .001). CONCLUSIONS: Manifest refraction techniques unique to echelette technology should be used to avoid over-minus end points. Autorefractors and aberrometers commonly use near-infrared light; thus, myopic results are expected with echelette achromatic technology. [J Refract Surg. 2020;36(5):334-339.].