We know that astigmatism can significantly affect visual acuity and quality of life when left uncorrected. Even mild astigmatism can reduce patient satisfaction and lead to visual fatigue. So why do we, as clinicians, tend to leave astigmatism uncorrected or try to mask it in our contact lens-wearing patients with astigmatism? Studies show that almost 50% of patients have astigmatism greater than 0.75D in one eye, and approximately 30% of these patients require toric lens correction.1 So, why the gap?
Common Misconceptions
Many eye care professionals tend to focus on masking astigmatism, and Dr. Patel believes that some practitioners may avoid fitting toric contact lenses due to a few misconceptions:
- They are harder to fit due to rotational instability.
- Toric lenses tend to be thicker, which may cause some patients to notice a difference in comfort.
However, recent advancements have made toric lenses easier to fit and have improved their rotational stability.
An Astigmatic Overview
Prevalence
Astigmatism is a prevalent eye condition that affects approximately 40% of adults and 15% of children.2 Those with myopia exhibit a significantly higher rate of astigmatism of 0.75D or more, occurring in 31.7% of patients, while this rate is only 15.7% for individuals with hyperopia.1 There are three types of astigmatism: with-the-rule (WTR), against-the-rule (ATR), and oblique.3
The average amount of astigmatism among contact lens wearers is 0.83D.4 A study by Young et al. (2011) reported the following data (Table 1) regarding the percentage of astigmatism in contact lens wearers.1
Table 1. The percentage of contact lens wearers exhibiting astigmatism of 0.75D, 1.00D, 1.50D, and 2.00D or more1
Signs and Symptoms
Common signs and symptoms include distorted vision, eyestrain, double vision (diplopia), headaches, glare, and halos around lights. Correction options include eyeglasses, contact lenses, and refractive surgery.3
Pathophysiology
The exact cause of astigmatism is not completely understood. Several factors contribute to its development, including age, race or ethnicity, genetic predisposition, environmental influences, extraocular muscle tension, visual feedback, and eyelid pressure.3
Risk Factors
Astigmatism is associated with several risk factors. One significant risk factor is age, as the incidence of astigmatism tends to increase with age. Additionally, pre-existing refractive errors, such as myopia, can elevate the risk of developing astigmatism. Studies show that male patients are more likely to develop both overall and against-the-rule (ATR) astigmatism. In contrast, female patients are more prone to developing corneal and with-the-rule (WTR) astigmatism.3
Other contributing factors include race, educational status, whether individuals live in urban or rural areas, the degree of nuclear and cortical cataracts, the axial length of the eye, and the presence of internal astigmatism.3
Astigmatism and the Impact on Quality of Life
Uncorrected and under-corrected astigmatism can significantly impact a patient’s vision and health-related quality of life, affecting their overall well-being in various ways. It affects visual acuity and contrast sensitivity in all lighting conditions. Visual disturbances, such as halos and glare caused by astigmatism, can interfere with daily activities, particularly nighttime driving. Additionally, cataract patients with astigmatism face an increased risk of dizziness and falls.3
It can also impact visual development, as children with oblique astigmatism are more likely to develop amblyopia.5 Additionally, it can reduce reading speed and fluency in both adults and children, leading to decreased productivity and limiting educational and employment opportunities. Individuals with this condition are more prone to making errors at work and tend to perform vision-related tasks more slowly.3
Putting Astigmatism In Focus
We have all encountered that new contact lens patient in the clinic who, despite having astigmatism, was told by their previous doctor that a “standard contact lens” (spherical equivalent) would be "good enough." This presents you with two options:
Keep It Simple: Choose to proceed with the spherical equivalent of the patient’s current prescription, even though this may not provide the best possible visual acuity for the patient.
Try To Improve The Visual Experience: Take the initiative to educate the patient about correcting their astigmatism and allow them to experience the difference between a spherical equivalent and toric correction, with the goal of providing them with a lens that optimizes their vision and enhances their overall experience.
What would you do?
Astigmatism and Contact Lens Dropout
Many patients choose to wear contact lenses to correct refractive errors because they seek freedom from glasses.5 A significant reason many patients discontinue the use of spherical soft contact lenses is their inability to tolerate the visual effects of residual astigmatism.5 For those using toric contact lenses, dropout is linked to an increased likelihood of experiencing visual issues related to cylinder power, lens rotation, and stability. Research shows that images lacking high spatial frequency details, such as ‘blurred’ images, can worsen symptoms of asthenopia. Discomfort ratings tend to increase more rapidly when experiencing blurred vision compared to when vision is clear.6
Benefits of Toric correction
Toric correction provides clear and stable vision, enhanced visual acuity, and freedom from glasses.3 Using toric contact lenses enhances vision quality and significantly reduces fatigue scores.5 Contact lens wearers have reported improved visual comfort when using a computer after correcting astigmatism compared to when it is uncorrected.6
Patients prefer toric correction over spherical contact lenses and report greater satisfaction when addressing astigmatism. Even correcting mild forms of astigmatism (<1.50D) can improve the quality of life for patients.3 A standard selection of toric soft lenses, which includes sphere powers ranging from +6.00 D to -9.00 D, alongside 3 cylinder powers and 18 different axes, effectively meets the needs of 90% of individuals with astigmatism,1 meaning practitioners have an abundance of contact lens brands to choose from.
Optimizing Patient Outcomes with CooperVision Toric Lenses
Comfort plays a key role in achieving optimal results and preventing dropout among contact lens wearers. For established contact lens wearers, discomfort is the main reason for lens dropout, while for new wearers, vision issues are the primary reason.7 Research indicates that symptoms of ocular discomfort tend to become more pronounced when there are perceived visual issues, particularly with daily disposable soft toric lenses. Therefore, it is crucial to use lenses that effectively address both vision and comfort to ensure patient success.6 Dr. Patel states that his practice has seen considerable success with CooperVision's toric lens offerings for astigmatic patients, including Biofinity® toric and MyDay® toric.
Biofinity Toric
Biofinity lenses can be worn daily or continuously for up to 7 days and 6 nights, with a recommended replacement schedule every 30 days. Biofinity toric lenses are available in standard toric, XR, and multifocal options. Table 2 provides an overview of each product's specifications.8
Table 2. Biofinity Toric Product Specifications8
What Makes It Unique?
Biofinity Toric is the most prescribed toric lens in the market.9 The family of Biofinity® contact lenses offers more than 243,000 prescription options,10 which means it has more options than all other monthly replacement SiHy toric brands combined. Biofinity® XR toric contact lenses are highly customizable and have an extended range. They are made to order and shipped to patients within 10 days.11
96% of Biofinity® wearers report satisfaction with their contact lenses.12 In a one-month daily wear study, Biofinity® toric multifocal lenses met or exceeded the comfort needs of at least 96% of wearers upon application.13
MyDay Toric
MyDay toric lenses are designed for daily wear and are replaced each day. Table 3 provides an overview of this lens.8
Table 3. MyDay Toric Product Specifications8
What Makes It Unique?
The prescribing rates for daily disposable lenses have risen significantly over the years, growing from 17.1% of daily wear soft lens fittings in 2000 to 46.7% in 2023.14 MyDay toric contact lenses mirror the Biofinity parameter range, offering the widest selection of prescription options available among daily contact lenses. This ensures that there is a suitable one-day option for patients who may not typically be able to use daily lenses.
In fact, 97% of MyDay toric wearers agree that switching from Biofinity toric lenses to MyDay toric lenses was easy. Additionally, 92% of MyDay toric wearers report that their MyDay toric lenses provide the same or better comfort as their Biofinity toric lenses.15
The Technology Behind Biofinity and MyDay Toric Lenses
The lenses are powered by Optimized Toric Lens Geometry™ and Aquaform® Technology, both of which are important to their performance.16
Optimized Toric Lens Geometry™
These contact lenses feature the market's #1 toric lens design.10 Optimized Toric Lens Geometry™ (Figure 1) is designed to enhance vision, comfort, fit success, and rotational stability. The result of this technology is patients achieving visual acuity similar to that in their spectacle correction.16
Figure 1. Schematic of Optimized Toric Lens GeometryTM Design16
Stability
Optimized Toric Lens Geometry™ also allows the lens to maintain uniform horizontal thickness across the ballast band, which enhances the lens's rotational stability. This results in a consistent and predictable orientation and rotational recovery upon contact lens insertion. The smooth, continuous ballast maximizes comfort during eyelid interaction, resulting in excellent comfort.16
Vision
The large toric optic zone enhances vision performance, ensuring clarity regardless of pupil size and in various lighting conditions. Moreover, the design features a unique back surface curvature, which minimizes movement on the eye, promoting stable lens positioning and a reliable fit.16
Dr. Lazon de la Jara explains that each CooperVision product utilizes the same technology and performs similarly in clinical settings. This allows eye care practitioners (ECPs) to easily switch between products to meet the specific needs of their patients, whether those needs are related to vision or changes in wearing modality.
Aquaform® Technology
Aquaform® Technology is an innovative material that allows contact lenses to retain twice their weight in water without the need for surface or wetting agents, resulting in exceptional comfort and natural wettability. The lenses provide lasting comfort and clarity while ensuring adequate oxygen transmission to keep the eyes clear and healthy, all within a soft and flexible design. The naturally hydrophilic silicone hydrogel lens helps reduce dryness, especially during activities that involve limited blinking, such as using digital devices.17
Table 4. Features, Advantages, and Benefits of Aquaform Technology17
Additional Features
In addition to Optimized Toric Lens GeometryTM and Aquaform® Technology, Biofinity Toric multifocal lenses also have Balance Progressive® Technology, which provides multiple correction zones in each lens, customized to the patient’s prescription, to assist them in seeing clearly at all distances.18
The Optiexpert contact lens calculator simplifies the fitting process for quick toric calculations, making it fast, easy, and accurate.19 Dr. Lazon de la Jara and Dr. Palombi discuss that using digital technology to streamline the fitting process can help reduce chair time, improve practice efficiency, and increase the likelihood of success by providing the right prescription for ECPs to use. This creates an opportunity to meet patient expectations and achieve high standards of care and service.
Enhancing Outcomes With Patient and Staff Education
Patient education is a vital part of the contact lens prescribing process. Educating the patient about astigmatism and how it is corrected with glasses and contact lenses is crucial. When discussing contact lens options with patients, it's important to consider their lifestyles and personalities. Daily contact lenses are an excellent choice for patients with busy lives, dry eyes, or concerns about hygiene. On the other hand, for those who have previously worn monthly contact lenses or have significant astigmatism, monthly contact lenses may be more suitable. Ultimately, the goal is to prioritize daily contact lens use.
Once the wearing schedule has been established, discuss the importance of full toric correction. If patients are in doubt, show them the difference between the spherical equivalent prescription and the toric correction using a loose cylinder lens over their eye in free space. A number of patients will notice the difference and opt to try toric correction. It is one thing to educate and describe to patients the difference, it is another to allow them to experience it for themselves.
Dr. Patel enjoys discussing options with astigmatic patients in their late 30s who are approaching presbyopia. He informs them that once they start experiencing presbyopia in a few years, they can use Biofinity Toric Multifocal lenses, which offer flexibility in vision correction.
Staff Education
Staff can also play a pivotal role in the success of the contact lens experience for patients in the practice. Discuss contact lens options during staff meetings, particularly with the front desk staff, to ensure a seamless experience for patients. Organizing "lunch and learn" sessions with contact lens representatives is an effective way to provide staff with information about available contact lens options.
During patient screening, staff should ask if the patient is interested in contact lenses. If the patient is already a contact lens wearer, staff should inquire about their vision and comfort levels. If the patient is unsatisfied, staff should encourage them to discuss their options with their doctor during their appointment.
During patient handoff, it is crucial to communicate the patient's preferences to ensure that:
- The patient feels that the staff are attentive and caring.
- The staff understand the significance of their conversations with the patient.
Briefly discuss wins as soon as they occur. Inform the staff if you have a patient who has transitioned to a better-fitting lens and reports an improvement in vision.
Conclusion
Toric correction is essential for addressing the visual distortions caused by astigmatism, enabling clear and crisp vision. Eye care professionals play a vital role in educating patients about the significance of achieving full astigmatism correction to enhance their daily experiences.
Biofinity and MyDay toric lenses are excellent choices that provide outstanding all-day comfort, featuring an innovative design that includes Optimized Toric Lens GeometryTM Design and Aquaform® Technology. These lenses also offer a wide range of prescription options, ensuring that each patient's specific vision needs are effectively met. With the right toric lenses, patients can enjoy sharper vision while engaging in their daily activities.
