Garg P, Shokrollahi P, Phan CM, Jones L. 3D printed contact lenses for the delivery of polyvinyl alcohol as a wetting agent The Association for Research in Vision and Ophthalmology Annual Meeting, Salt Lake City, May 7, 2025 [ Show Abstract ]

Purpose
To print a proof-of-concept 3D printed contact lenses to release polyvinyl alcohol (PVA) as a wetting agent, using 3D printing technology.

Methods
A model CL was designed using a computer-aided design software (FreeCAD 0.19) and 3D-printed using a commercial masked-stereolithography 3D printer. The printer was retrofitted with a humidity and temperature control kit to enable printing at ~95% humidity and 37°C. The polymer solution consisted of 10% (w/v) GelMA, 5% (w/v) PVA as a wetting agent, a photoinitiator, and yellow dye as a light absorbing agent to reduce unwanted light leaks. These 3D printed lenses were washed with warm PBS to remove any uncured polymer solution and post-cured with UV light. The print quality was assessed by determining the ratio between the theoretical area vs the actual printed area and the theoretical circumference vs the actual printed circumference. To study the PVA release from these CLs, they were incubated in glass vials with gentle agitation with 8 mL PBS at 35°C. At each indicated time point 300 µL of the solution was removed for detection of PVA and replaced with fresh PBS. The release kinetics was studied by different mathematical models using GraphPad software.

Results
The CLs were 3D printed in an hour and the print quality scores were 0.96 and 1.04 for area and circumference ratios respectively. The minimum thickness for the lenses that was reliably printed each time using the current 3D printing setup was 400 µm. Around 4711 µg of PVA was released over the study duration of 8 hours, supporting our concept PVA-loaded 3D printed lenses. The release kinetics showed high linearity with Higuchi’s model which describes the release rate of drugs from matrix systems based on diffusion.

Conclusions
This study attempted to print a proof-of-concept 3D printed contact lens that can release PVA from GelMA. Also, these 3D printed contact lenses displayed a good print quality score. Future work will focus on optimizing the thickness and transparency of these lenses as well as tuning the release kinetics of PVA.

Luensmann D, Woods J, Jones L. Coverage of ametropia with a planned replacement soft contact lens portfolio AOA Optometry's Meeting, Minneapolis, USA, Jun 27, 2025 [ Show Abstract ]

BACKGROUND: Soft lens power ranges are often broad for spherical prescriptions, but there is typically less coverage for astigmatic prescriptions, particularly with multifocal lenses. This unequal coverage within a lens brand may mean refitting previously successful lens wearers with a different brand when they need a toric or multifocal correction. This could increase chair time and requires adaptation to a different lens fit, which could negatively impact lens comfort and/or handling and therefore patient satisfaction. This analysis reviewed the coverage of a specific planned replacement portfolio.

METHODS: In a secondary analysis, prescription data of 101,973 optometric clinic patients aged 14-70 years were evaluated: 59,631 female and 42,342 male . The prescriptions available in a planned replacement portfolio spanning spherical and toric prescriptions were evaluated to calculate the coverage in non-presbyopic and presbyopic age groups.

RESULTS: In the non-presbyopic group (age 14-39; n=47,195) and presbyopic group (age 40-70; n=54,778), astigmatism of at least -0.75DC was present in 39% and 44% of eyes respectively.
Spherical corrections are acceptable for eyes with no more than 0.50DC astigmatism. If a lens brand is available in single-vision prescriptions +6.00 to -12.00D and multifocal prescriptions +6.00 to -10.00D, they would cover 99.9% and 99.7% of eyes respectively.

Toric corrections are warranted for eyes with astigmatism of at least -0.75DC, and if a lens brand is available in single vision: sphere +6.00 to -9.00D and up to -2.75DC in all axes, and multifocal: sphere +4.00 to -6.00D and up to -1.75DC in all axes, plus up to -2.75DC in axes 90±20 and 180±20, these ranges would cover 95.3% and 92.3% of astigmatic eyes in the respective age groups.
This results in a total coverage of 97.3% across all age groups and prescriptions. In contrast, if the toric multifocal option was not available, the total brand coverage reduced to 78.3%.

CONCLUSION: This analysis demonstrates that robust coverage was achieved for both presbyopic and non-presbyopic populations in this planned replacement portfolio. Such high coverage helps facilitate a smooth transition and adaptation for practitioners and patients when needing to switch from single vision spherical lenses to toric and/or multifocal lenses.

Luensmann D, Woods J, Jones L. ePoster: Coverage of ametropia with a planned replacement soft contact lens portfolio AOA Optometry's Meeting, ePoster, May 29, 2025 [ Show Abstract ]

BACKGROUND: Soft lens power ranges are often broad for spherical prescriptions, but there is typically less coverage for astigmatic prescriptions, particularly with multifocal lenses. This unequal coverage within a lens brand may mean refitting previously successful lens wearers with a different brand when they need a toric or multifocal correction. This could increase chair time and requires adaptation to a different lens fit, which could negatively impact lens comfort and/or handling and therefore patient satisfaction. This analysis reviewed the coverage of a specific planned replacement portfolio.

METHODS: In a secondary analysis, prescription data of 101,973 optometric clinic patients aged 14-70 years were evaluated: 59,631 female and 42,342 male . The prescriptions available in a planned replacement portfolio spanning spherical and toric prescriptions were evaluated to calculate the coverage in non-presbyopic and presbyopic age groups.

RESULTS: In the non-presbyopic group (age 14-39; n=47,195) and presbyopic group (age 40-70; n=54,778), astigmatism of at least -0.75DC was present in 39% and 44% of eyes respectively.
Spherical corrections are acceptable for eyes with no more than 0.50DC astigmatism. If a lens brand is available in single-vision prescriptions +6.00 to -12.00D and multifocal prescriptions +6.00 to -10.00D, they would cover 99.9% and 99.7% of eyes respectively.

Toric corrections are warranted for eyes with astigmatism of at least -0.75DC, and if a lens brand is available in single vision: sphere +6.00 to -9.00D and up to -2.75DC in all axes, and multifocal: sphere +4.00 to -6.00D and up to -1.75DC in all axes, plus up to -2.75DC in axes 90±20 and 180±20, these ranges would cover 95.3% and 92.3% of astigmatic eyes in the respective age groups.
This results in a total coverage of 97.3% across all age groups and prescriptions. In contrast, if the toric multifocal option was not available, the total brand coverage reduced to 78.3%.

CONCLUSION: This analysis demonstrates that robust coverage was achieved for both presbyopic and non-presbyopic populations in this planned replacement portfolio. Such high coverage helps facilitate a smooth transition and adaptation for practitioners and patients when needing to switch from single vision spherical lenses to toric and/or multifocal lenses.

Phan C, Walther H, Ho B, Jones L. Development of a novel in vitro blink model for measuring prelens non-invasive break-up time
The Association for Research in Vision and Ophthalmology Annual Meeting, Salt Lake City, May 8, 2025 [ Show Abstract ]

Purpose
To develop an in vitro blink model for measuring prelens non-invasive break-up time of contact lenses with a keratograph.

Methods
The model was designed using CAD (computer-aided design) software and fabricated using a combination of 3D printing, CNC (computer numerical control) machining, and molding processes. The base structure of the eyeball was 3D-printed, and the front surface of the eyeball was cast using acrylic resin mixed with graphite powder in an ultrasmooth polydimethylsiloxane (PDMS) mould. The lower eyelid was designed to hold the eyeball and the lower tear meniscus. The base structure of the eyelid was 3D-printed using flexible resin (Flex 50A) on the FormLabs 3B (Formlabs Inc., Somerville, MA, USA), and then moulded into its final shape with polyvinyl alcohol. The blink speed of the model was set to 150 mm s-1 for both opening and closing. The model’s ability to generate a stable tear film over a contact lens (senofilcon A) was validated using non-invasive keratographic break-up time (NIKBUT) with the OCULUS Keratograph 5M. 20 µL of phosphate-buffered saline (PBS) is added to the upper eyelid using a pipette, and the model is allowed to equilibrate for three blinks before each measurement.

Results
The resulting eyeball is black in the central corneal region, providing the necessary contrast to reflect the concentric rings projected by the keratograph. During each blink, the hydrogel in the upper eyelid comes into contact with the lower tear meniscus and evenly distributes the tear fluid across the eyeball during the upward motion of the blink. Without a contact lens, the tear film breaks immediately over the hydrophobic acrylic surface of the eyeball. The NIKBUT for senofilcon A ranged from approximately 5 to 7 seconds, aligning with clinical observations. The model also includes a fluid reservoir located in the lower eyelid, used to rehydrate the hydrogel. Additionally, two inlets can be attached to the lower eyelid to control fluid flow into and out of the model.

Conclusions
The developed blink model consistently forms a tear film over a contact lens during the upward blink motion, using the lower tear meniscus as the fluid source.

Shokrollahi P, Garg P, Hui A, Phan,C, Jones,L. PVA-Based Hydrogel Inserts for Atropine Delivery for Myopia Treatment The Association for Research in Vision and Ophthalmology Annual Meeting, Salt Lake City, May 4, 2025 [ Show Abstract ]

Purpose
Myopia progression is a global problem, with 50% of the world’s population predicted to be myopic by 2050. This project aimed to develop atropine (ATR)-releasing ocular inserts based on polyvinyl alcohol (PVA) hydrogels for the treatment of myopia, which could be complementary to other myopia control methods, such as spectacles or contact lenses.

Methods
PVA was dissolved in water at 80°C to prepare a 10% (w/v) solution. The solution was divided into two parts. ATR was added to one part to give 0.6% (w/v) concentration, and the other part acted as a control. Both groups were transferred to a silicon mold (5.5mm diameter, 0.2mm height, ~100µl) and subjected to six freeze-thaw cycles, alternating between freezing at -20°C for 16 hours and thawing at room temperature for 8 hours
Mechanical properties were studied via a compression test (TA instruments, Hamilton, USA), and the morphology was assessed using scanning electron microscopy (Quanta FEG 250, FEI, USA). The release of atropine was then measured in 1mL of phosphate-buffered saline every 30 minutes for 6 hours.

Results
SEM analysis revealed a highly interconnected porous structure and a narrow pore size distribution (12±8µm, Figure 1A). The hydrogels displayed about 0.86 kPa compression modulus and 21.81 kPA compression strength at 30% strain (Figure 1B) and withstood 5 compression cycles with minimal changes in modulus. The discs released about 25% of the initial ATR loaded (~600 µg) in the first 30 min and about 50% in 1 hour. Nearly, 100% of the cargo was released in 3.5 hours (Figure 1C). The release profile followed first-order kinetics (R2 = 0.9628).

Conclusions
The open pore network of the discs can accommodate water and improve the elastic soft “feel” of the insert, while being structurally robust and easy to handle. This hydrogel insert based on PVA, a polymer with FDA approval for biomedical applications, can support the gradual release of ATR up to 3.5 hours and helps avoid the side effects of 1% ATR eye drops, while providing a similar cumulative concentration of the drug to the eye. Future studies will focus on optimizing parameters to extend the release duration.

Walsh K, Vega J, Chisholm R, Cvarch B, Schwiegerling J, Luensmann D, Marullo R. Performance of two contact lens designs in a clinical setting and through computational optical modelling Global Specialty Lens Symposium, Las Vegas, Jan 17, 2025

Woods J, Luensmann D, Guthrie S, Vega J, Richdale K. Do objective and subjective outcomes align when evaluating multifocal soft lens performance? British Contact Lens Association Meeting, Birmingham, UK, Jun 5 to 7, 2025 [ Show Abstract ]

Purpose:
The success of multifocal soft lenses (MF) can differ depending on whether objective or subjective evaluations are considered. This study compared vision results for in-practice acuity and subjective feedback after participants had worn two different MF designs for 1-month.

Methods:
This prospective, participant-masked, randomised, cross-over, daily-wear study involved habitual MF wearers at 5 sites. Study lenses were monthly replacement, silicone hydrogel: comfilcon A (comMF) and lehfilcon A (lehMF). After 1-month wearing each lens, high-contrast logMAR distance, intermediate and near acuities were measured, and participants rated their experience using 0-100 visual-analogue scales, 4-point agreement questions and 5-point preference Likert scales.

Results:
59 participants completed; mean(SD) demographics: 53.2±6.7 years, -1.57±2.14 refractive spherical component, +1.86±0.46 near addition. Both lenses were worn >12 hours/day (p=0.96). Comfort was not different between lenses (all >80, p>0.05). High-contrast acuity was not different (p>0.05) between lenses for distance and intermediate, but near was 2.5 letters better with comMF (p<0.05). Also, more participants preferred comMF for vision for ‘digital device use’ and ‘near’ (both p0.05); no preferences favoured lehMF. While ratings for ‘overall satisfaction with vision’, ‘vision in dim/dark light conditions’, ‘consistent vision throughout the day’ and ‘crisp, clear vision overall’ showed no differences (all p>0.05), comMF was rated 9 points better for ‘crisp, clear vision when using digital devices’ (p<0.01). Differences favouring comMF were reported in all four near vision task agreement questions: when using ‘laptop’, ‘phone’, ‘reading’, ‘digital devices’) plus for ‘crisp vision at all distances’ (all p<0.05). No rating or agreement data favoured lehMF.

Conclusions:
Both lenses provided good overall performance. comMF demonstrated better near acuity which aligned with better subjective visual performance outcomes related to near-work and digital device use. These results support the value of including real-world experience and subjective feedback in multifocal fitting and evaluation.