Daniel H. Chang, MD

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Presbyopia has long been both a challenging and frustrating condition for patients and physicians alike. 

The problem has only magnified in recent years by society’s growing dependence on digital devices. Satisfying patients' full range of visual needs is now more challenging than ever.

Consider the statistics: Adults spend an average of more than 11 hours per day interacting with some form of media, including checking their smartphones every 10 minutes.

Researchers reaching for the stars to cure presbyopia



Even baby boomers are changing the way they communicate—they are seven times more likely to text than talk, and they use smartphones and tablets nearly 4 hours a day.

The numbers are staggering: About 1.8 billion people globally have presbyopia,

 and 128 million people in the United States suffer from near vision loss.

Although individuals have varying degrees of difficulty due to presbyopia, most report difficulty reading as part of their everyday activities.

A survey of 797 patients aged 40-55 years revealed that 96% of respondents claimed at least one daily activity is "somewhat affected" by presbyopia symptoms, while near one-half said the impact is “extreme.”

Patients find workarounds to deal with near-vision loss, including keeping flashlights in every room, relying on magnifying mirrors, and placing special labels on pill bottles. They report needing help to read driving directions, printing out electronic documents, and enlarging text on their devices.

Technology puts focus on presbyopia laser correction

No matter how creatively patients address their presbyopia, they are as a group unhappy. They struggle regularly with their near-vision loss, sometimes to the point of feeling helpless.

Although choices for near-vision correction include glasses, contact lenses, monovision corneal laser refractive surgery, corneal inlays, and IOLs, 90% of patients aged 40-55 years remain frustrated or irritated with presbyopia.

In part, this is due to the fact that even though nearly two-thirds of patients with presbyopia seek help from their eye-care provider, barely one-half report obtaining the information they needed, with just 15% of those surveyed indicating that they received printed educational material.

Eye-care providers are falling short in managing patients with presbyopia. With increasing technology and treatment options, it is imperative that eye-care providers increase efforts to engage patients, educate them, and to provide solutions that more completely address patients’ needs and concerns.

Presbyopia-correcting IOLs enhance customization 

The various surgical approaches to treating presbyopia harness a variety of mechanisms for extending depth of field. 

These include corneal-based approaches with excimer lasers, conductive keratoplasty, and corneal inlays as well as lens-based approaches with a variety of presbyopia-correcting IOL options.

Regardless of the actual technique, in the absence of movement and true accommodation, pseudoaccommodation leverages the eye's optical properties to increase depth of field through a variety of mechanisms, including:


higher-order aberrations (e.g., spherical aberration and coma)

diffractive/nondiffractive IOL technologies

Small-aperture optics or the pinhole effect is a method of pseudoaccommodation that increases the depth of field without the need for ciliary muscle engagement. 

This occurs with miosis, or iris constriction and pupil size reduction. This mechanism and the resulting improvement in the depth of field can be utilized to relieve presbyopia symptoms.

The position of the pinhole is key to increasing the depth of field without constricting the peripheral visual field. If a pinhole is placed in front of the eye, like on the spectacle plane, the visual field is greatly reduced.

How pinhole camera effect in small-aperture implant corrects presbyopia

A pinhole on the corneal plane has lesser peripheral field impact. A small aperture near the iris plane or small pupil would be ideal to provide increased depth of field while maintaining a full visual field.

Pupillary miosis can improve near vision, but distance vision can be lost when a pupil gets too small. Therefore, there is no specific number that describes the optimal pupil size for all individuals.

Rather, the best way to think about pupil size is as a percentage of the natural pupil size. This approach accounts for factors such as lighting and pupil size variability for each individual eye.

Studies shows that in all lighting conditions, pupils that are 40% to 50% of their natural pupil size will maximize near-vision improvement without sacrificing relative distance visual quality (see 

Therefore, achieving an optimal pupil range allows for maximum image quality for both far and near vision.

Study targets topical medication adherence, visual field progression

Presbyopia is an increasingly common age-related condition that affects almost all older patients on a daily basis, bringing frustration and irritation to the majority of sufferers.

Techniques that harness the principle of small-aperture optics and the pinhole effect, particularly utilizing the pupil, may hold promise for an improved approach to presbyopia correction.

This optimal method would place a pinhole at the iris plane to extend the depth of field without impairing the visual field.

As eye-care providers, we should more assertively educate and treat our older patients for this near-ubiquitous condition.



Cataract and refractive surgeon, Empire Eye and Laser Center, Bakersfield, California


Financial disclosure: Dr. Chang is a consultant for Allergan and


1. Nielsen Total Audience Report Q1 2018. https://www.nielsen.com/us/en/insights/report/2018/q1-2018-total-audience-report/. Accessed June 12, 2020.

2. Fricke TR, Tahhan N, Resnikoff S, et al. Global prevalence of presbyopia and vision impairment from uncorrected presbyopia: systematic review, meta-analysis, and modelling. 

. 2018;125(10):1492-1499. doi: 10.1016/j.ophtha.2018.04.013.

3. Zebardast N, Friedman DS, Vitale S. The prevalence and demographic associations of presenting near-vision impairment among adults living in the United States. 

. 2017;174: 134–144. doi: 10.1016/j.ajo.2016.11.004

4. Data on file, Allergan. Survey of 797 patients aged 40-55 years.

5. Data on file, Allergan; Full Quantitative Summary. Survey of 1339 patients aged 40-55 years.

Articles

Just as evolving technology is changing patients' visual demands, eye-care providers should increase their awareness and efforts to fill current gaps.


Presbyopia: Rethinking approach to better meet patients’ needs 

With modern presbyopia-correcting IOLs, patients are generally happy with their quality of vision after surgery.

Nevertheless, some patients are unhappy even with Snellen visual acuity of 20/20 or better. While it may sometimes be tempting to dismiss these patients as unreasonable or “crazy,” understanding what makes these patients dissatisfied even with good Snellen visual is important for their proper management.

When using presbyopia-correcting IOLs, I always evaluate patients after the first eye is done before proceeding to the second eye. This way, I can address any potential visual quality and function issues prior to committing to the second eye.

If a patient says things are “blurry,” I first make sure that they are describing their best-corrected visual acuity in the pseudophakic eye.

If they are still wearing old glasses or if they are being distracted by their cataractous eye, then proceeding with the second eye surgery makes sense.

However, if they are indeed unhappy about the vision in the operative eye, I have them describe their symptoms in more detail.

Dissatisfaction with vision in spite of good Snellen acuity can be grouped into two primary causes: issues of edge-contrast (visual quality) and night-vision symptoms (dysphotopsias).

I distinguish these two categories by having patients describe the situation(s) in which they are unhappy with their vision. If their complaints are related to the sharpness of letters when looking at an eye chart, the issue is visual quality. If their complaints are primarily related to what they see around lights at night, the issue is dysphotopsia. In both cases, I try to correlate their descriptions with what I know is going on optically with the lens implant and eye.

Visual acuity is dependent on the ability to distinguish the edges of an optotype (such as an E on the eye chart). Both contrast (the difference in intensity between the background and the foreground) and brightness (light) help us to discern the edges.

In an ideal situation, contrast and brightness are both at 100%, and there is no blur, providing a nice, sharp optotype and a high-quality visual experience (Figure 1).

Contrast and lighting are related. In the example above, when the light is dimmed, the optotype remains black while the background becomes darker, so the edge of the optotype becomes harder to distinguish. This is because the intensity difference between the foreground and background decreases (Figure 2a).

Similarly, if contrast sensitivity is decreased, the optotype becomes lighter while the background remains white, so there is a corresponding reduction of intensity difference between foreground and background (Figure 2b).

If lighting is dimmed in a low contrast state, the effect is compounded, and the optotype becomes even more difficult to see (Figure 2c).

In general, if a patient is having trouble with contrast, the simplest thing to do is to turn up the light.

Blur can be thought of as a spreading of the transition between foreground and background (Figure 3). Instead of a sharp transition from black to white, the edge transition of the optotype becomes more gradual. As the amount of blur increases, the relative contrast at the edge decreases, making it increasingly difficult to distinguish a crisp separation between black-and-white (Figure 3a, b, and c).

Increasing illumination can help to some degree, but magnifying the object (e.g. by moving it closer) makes it easier to see (Figure 4a, b, and c).

Other times a patient might say the letter itself is sharp but there’s a “glow” or a “shadow” or “fuzziness” around it (Figure 5).

This can occur in patients with multifocal IOLs or even extended-depth-of-focus (EDOF) IOLs. Since there is a sharp edge present, patients with these symptoms typically have good visual acuity and function and basically need reassurance and time for neuroadaptation. Even in a discerning, Type A patient, the process of neuroadaptation can take several months, rarely needing an IOL exchange for improvement.

With any of these manifestations of “blurry” vision, one should always look for possible secondary causes such as residual refractive error, dry eye, posterior capsular opacification (PCO), and cystoid macular edema.

Another reason that patients might be unhappy with objectively 20/20 vision is dissatisfaction with the quality of vision at night. Dysphotopsias are the result of out-of-focus light hitting the retina. Whether from ocular aberrations, lenticular light scatter, or pseudoaccommodating IOLs, dysphotopsias vary greater in brightness and appearance.

For clinical trials, the FDA classifies dysphotopsias into three distinct categories: glare/flare; halo; and starburst. Each of these has a different appearance to the patient and occurs for different optical reasons (Figure 6).

Glare or flare, which may also be described as smearing or blur around the point source of light, can be due to refractive error, ocular surface problems, PCO, and nuclear cataracts; and it is less likely to be directly associated with any particular IOL optics.

Halo, or a ring around the point source of light, is common with multifocal IOLs. These lenses have two focal points, which can be seen on a defocus curve as two peaks. Between the two peaks, there is a drop-off in energy distribution in the intermediate range. That dip in the defocus curve correlates with a dip in off-axis light, or the gap between the center and the ring in the halo. The size of the halo is related to add power, with larger halos associated with higher add powers.

Starbursts may be described by patients as streaks or rays of light emanating from the point source. These can occur with refractive error, ocular surface problems, posterior capsular folds/PCO, or diffractive IOLs.

Dysphotopsias can also occur in different forms and/or combinations (Figure 7).

When looking at illustrations of dysphotopsias, it is important to recognize that the ability to represent dysphotopsias in a picture is limited by the contrast of the paper or display on which we view at the illustration. With only 256 levels of gray, our digital images are a far cry from the contrast ratios relevant to night vision, which can be greater than 1:1,000,000.

As new presbyopia-correcting IOLs become available, the differences in optics and design mean new trade-offs between depth of focus and dysphotopsias.

For example, while diffractive multifocal IOLs can produce a single bright halo, diffractive EDOF IOL patients tend to describe starbursts and multiple fine concentric halos that produce a “spider-web” effect.

Overall, I have seen greatly reduced night vision complaints with EDOF IOLs as compared to multifocal IOLs, but I foster this with appropriate preoperative counseling.

In conclusion, whether it’s visual quality or dysphotopsias, we have much more to learn about how our presbyopia-correcting IOL patients’ visual experiences correlate to our traditional clinical testing results.

Instead of shunning patients with visual quality complaints following implantation of these lenses, we should embrace the opportunity to learn from their symptoms not only for how best to manage them, but also better to counsel future patients-and to create our next generation of IOLs to correct presbyopia.


Dr. Chang is in private practice at Empire Eye and Laser Center in Bakersfield, CA. He is a consultant to Johnson & Johnson Vision.

Troubleshooting post-presbyopia IOL complaints

,” a blog series featuring contributions from members of the ophthalmic community. These blogs are an opportunity for ophthalmic bloggers to engage with readers with about a topic that is top of mind, whether it is practice management, experiences with patients, the industry, medicine in general, or healthcare reform. The views expressed in these blogs are those of their respective contributors and do not represent the views of 

	In this collaborative blog post, learn how building rapport and sharing like-minded philosophies benefits your practice and your patients. Five ophthalmologists share how to make the most of a co-managed relationship for smoother patient handoff, improved preoperative experiences, and better postoperative outcomes.

Dr. Donnenfeld“The most important aspect of co-management is that both parties collaborate in providing the best possible care for the patient,” said Eric Donnenfeld, MD, who practices with Ophthalmic Consultants of Long Island and Connecticut, and is clinical professor of ophthalmology, New York University.

	One of the ways this plays out in his practice is making sure patients arrive ready for surgery.

	“We have emphasized to our optometric network the importance of managing the ocular surface in patients coming in for cataract and refractive surgery,” he said. 

	Previously, if patients arrived for a surgical evaluation but their ocular surface was not optimized, clinicians had to defer surgery. Now, the optometric network manages ocular surface disease before referring patients.

	“The patient comes in and has already been treated appropriately, whether it be with an immunomodulator, a steroid, omega-3 supplements, or LipiFlow thermal pulsation,” he said. “It is so helpful when the patient comes in for a cataract or LASIK evaluation with the best ocular surface possible.”

	Dr. Donnenfeld noted the importance of the optometrist’s recommendations.

	“A doctor who has been taking care of that patient for a decade is going to know a lot more about that patient’s personality, history, and vision care experiences than I can learn in a short consultation, so their counsel becomes very important in my decision as to what lens the patient should receive,” he said.

2. Look for partners who share your philosophy 

Dr. KontosWhen building a successful co-management network, ophthalmology practices should seek out and nurture relationships with like-minded partners. 

	“We look for optometrists who are progressive, engaged in continuing education, and who are always looking to learn more about what is happening in eye care,” said Mark Kontos, MD, who is in private practice with Empire Eye Physicians, Spokane, WA, and Coeur d'Alene, ID.  The practice has co-management relationships with about 75 optometrists.

	“A fundamental theme in our practice is that we want to be on the cutting edge of innovation in ophthalmology,” Dr. Kontos said.

	For example, his practice likes to use advanced technology lenses to correct astigmatism and presbyopia, but that can be a source of conflict if the referring optometrist has little interest in or knowledge about the technology.

	“We feel that new lenses like the extended-depth-of-focus IOLs [Tecnis Symfony, Johnson & Johnson Vision] are beneficial to patients, and so it is important that we are on the same page with our referring doctors,” he said.

	To keep co-management partners up to date, his practice presents a large education event each year. Speakers discuss new technology and the latest research in ophthalmology. 

	In addition, ophthalmologists in the practice also meet with co-managing partners during dinner and lunch meetings once or twice a month to discuss issues related to patient care and to maintain strong lines of communication.

	“If they can spend a half day in the practice, that gives them an opportunity to see surgery and us a chance to educate them about what we are doing in our practice,” he said. “We also can get valuable feedback from the optometrists on what patients are saying about the combined care we are providing.”

3. Establish relationships based on best practices

Dr. Chang“With co-management, you have to be really careful from a documentation standpoint,” said Daniel H. Chang, MD, who is in private practice at Empire Eye and Laser Center, Bakersfield, CA. To ensure thorough documentation, his practice uses a five-form process that includes consent for co-management, requiring signatures from the patient, surgeon, and co-managing optometrist.

	Prior to surgery, he sends a surgery appointment schedule to give the referral optometrist an idea of the anticipated course of treatment. After surgery, he sends a co-management operative report with relevant details about the surgery.

	After surgery, he documents appropriate transfer of care. When Dr. Chang examines the patient postoperatively and determines that he or she is doing well, he sends the transfer agreement to the optometrist, as well as a pre-labeled transfer response.

	This way, the optometrist can confirm that the patient returned for continued follow-up and report the postoperative findings from that visit.

	“These forms demonstrate an open communication between the surgeon and the co-managing optometrist,” he said.

	About 10% to 20% of his cases are co-managed. To enhance his collaborative relationship with community optometrists the decision was made not to include an optical shop at his new practice location. This reduces the concern from referring optometrists that he may not return their patients and may even represent unwelcome competition for spectacle sales.

	“We still have optical patients at our original location, and they remain a welcome part of our practice,” Dr. Chang said. “But referred surgical patients never know that we sell glasses.”

4. Build rapport with your co-management partners

Dr. IrshadStrong co-management relationships are especially important in rural areas, where patients may need to travel long distances to see an ophthalmologist. When forging a bond in these wide-open spaces, however, Farhan A. Irshad, MD, with Wallace Eye Associates, Alexandria, LA, found that it helps to go the extra mile.

		When he was new to the practice and the community, Dr. Irshad said it was most effective to visit practices to introduce himself.

		“It meant a lot to them that I traveled the distance to their location and could see their office, meet their staff who I would also be working with, and see their equipment,” he said.

		“With every first-time referral, I actually called the doctor after surgery in addition to sending a letter,” he said. During the conversation, he detailed his findings from the examination, the treatment plan, and why he chose that plan.

		Practice services also support these relationships. For example, his practice sends billers and coders to assist the optometrists’ teams with co-managed cases.

		“With the changes in rules and regulations, some of them are not familiar with the nuances of medical billing because it’s not something they do on a regular basis,” Dr. Irshad said. “Sending our team in to help has gone a long way to building a solid partnership.”

Dr. YeuWhether ophthalmologists receive referrals from an optometrist associated with a corporate chain or private practice, they need to understand how each practice functions so they can better serve that practice.

		That begins with some mechanism to organize information about each practice.

		“We created an Excel spreadsheet of preferences, contact information, and available diagnostic and imaging tools,” said Elizabeth Yeu, MD, assistant professor, Eastern Virginia Medical School, and partner, Virginia Eye Consultants, Norfolk, VA. “Just like there is such a breadth of MD practices, there is a breadth of OD practices.”

		“We find out from each co-managing partner exactly how they would like their patients to be managed,” Dr. Yeu said.

		For example, some expect patients to be returned as soon as possible, whereas others may ask the ophthalmologist to take care of the patient throughout the postoperative period or for everything related to glaucoma, for example, and just return the patient for glasses and contact lenses.

		“This is how you are going to create a successful network,” Dr. Yeu said. “Not all referring practices are created equal, so you have to customize your specific relationship with the specific practice that is referring to you, but you need to begin with an organized process.

		Daniel H. Chang, MD
		P: (661) 325-3937; E: 


		Dr. Chang is a consultant to Johnson & Johnson Vision.


		Dr. Donnenfeld is a consultant to Allergan, Bausch + Lomb, Johnson & Johnson Vision, Kala, RPS, Shire, Sun, TearLab, and TearScience.

		Mark Kontos, MD
		P: (509) 928-8040; E: 


		Dr. Kontos is a consultant to Johnson & Johnson Vision.

		Elizabeth Yeu, MD
		P: (757) 622-2200; E: 


		Dr. Yeu is a consultant to Johnson & Johnson Vision. 

Five ophthalmologists share how to make the most of a co-managed relationship for smoother patient handoff, improved preoperative experiences, and better postoperative outcomes.

Five secrets to success with co-management

White light is comprised of different wavelengths of visible light, ranging from red (700 nm) to violet (400 nm).  As white light passes through an optical system, each of its component wavelengths bends independently. 

By Snell’s law, faster-moving longer wavelengths bend less than slower-moving shorter wavelengths, dispersing the various colors to different focal points along the optical axis.

This dispersion is referred to as longitudinal chromatic aberration (LCA). The impact of LCA is thought to be greater than the impact of all higher-order aberrations

, but its effect on IOLs or on pseudophakic vision has not been well characterized.

The Abbe number can be used to quantify LCA in optical materials. Based on Abbe number calculations, the phakic eye has a baseline LCA of about 1.25 D of chromatic refractive difference between red (650 nm to 700 nm) and blue (450 nm) light.

 In pseudophakic eyes, the IOL implanted can potentially increase or decrease the eye’s LCA relative to the phakic state, depending on the properties of the IOL.

Unfortuntaely, Abbe numbers are not made publicly available by IOL manufacturers.  Additionally, the effects of chromophores and diffractive patterns on LCA have not been published. A study presented at the 2016 Association for Research in Vision and Ophthalmology (ARVO) meeting attempted to further characterize LCA in IOLs, through 

To explore the amount of ocular LCA of different IOLs in vitro, five intraocular lenses made from two different hydrophobic acrylic materials were placed in an ACE model eye on an optical bench. The ACE (Average Cornea Eye) aphakic eye model simulates a human cornea with average spherical aberration (SA) and LCA.

Through-focus modulation, transfer-function (MTF) measurements were performed using a 3.0-mm aperture.  Measurements were performed at five different wavelengths: 450 nm, 500 nm, 550 nm, 600 nm, and 650 nm. LCA was expressed as the difference in optical power for the different wavelengths.

Figure 1: Chromatic aberration over the range of 450 nm to 650 nm expressed in diopters in the spectacle plane. The dashed line represents the aphakic eye model chromatic aberration of 1.04 D. Courtesy of Daniel H. Chang, MD

LCA of the aphakic eye model was 1.04 D (Figure 1).  The first hydrophobic acrylic material had LCA of 1.30 D (Tecnis, Johnson & Jonson Vision Care/Abbott Medical Optics), and the second hydrophobic material had LCA of 1.77 D (Acrysof, Alcon Laboratories).

The presence of a chromophore did not significantly affect LCA. Multifocal diffractive rings did not affect the LCA at the far focal point, but an achromatic diffractive ring pattern significantly reduced LCA as measured 

This study demonstrated that in a physiologically representative eye model the chromatic aberration of IOLs can be measured and varies widely for different IOL materials. 

However, bench testing is insufficient to fully understand optical quality because it is such a pure measure. It is difficult to accurately model the imperfections of the human eye-and impossible to model all the complex factors that go into the human visual system, including higher order aberrations, ocular surface, and retinal factors; emotions, moods, and fatigue; and the ability of the brain to compensate for aberrations, interpret visual stimuli, and interpolate visual information.  

A second test was devised to evaluate LCA clinically. This is a challenge, because there is no ophthalmic diagnostic device that measures chromatic aberration. Therefore, a chromatic refraction technique was developed to characterize the impact of LCA on pseudophakic vision.

In this prospective clinical pilot study, 23 patients were implanted with a Tecnis ZCB00 lens in one eye and an Acrysof SN60WF lens in the fellow eye. The SN60WF lens does have a chromophore, but bench top testing indicated that the chromophore does not affect LCA.

At 30 to 60 days after the second-eye surgery, chromatic refractions were performed. To do this, a white light manifest refraction was performed using a standard high-contrast Snellen chart to correct for any residual refractive error.

Then, using a larger optotype (e.g., the 20/50 line), the chart was covered with a 650-nm red filter and the sphere was readjusted. The same was done with a 450-nm blue filter, and all three numbers were recorded.

The difference between the red and blue refractions is the chromatic refractive difference. Note that the limitations of available color filters significantly reduced the overall brightness of the eye chart, although contrast was slightly enhanced by the red filter.

Figure 2: Median difference in refraction under mesopic conditions when refracted using the blue filter and the red filter. The bars represent the mean and standard error of the mean of 23 patients. Courtesy of Daniel H. Chang, MD

measurements with the ZCB00 lens resulted in a difference in refraction between the red and the blue color filter of 1.12 D in photopic conditions and 1.11 in mesopic conditions. With the SN60WF lens the chromatic refractive difference was 1.28 in photopic conditions and 1.30 in mesopic. The difference between the two materials under mesopic conditions was statistically significant (Figure 2).

 measurements correlate with optical modeling and bench testing. The lens material with higher LCA in bench testing indeed resulted in a greater chromatic refractive difference in the clinical study

Further studies are needed to understand the clinical significance of chromatic refractive differences. Low-contrast sensitivity and glare situations might be affected by LCA and chromatic refractive differences.

The human visual system can tolerate a significant amount of monochromatic aberrations, but it is unclear how much LCA can be tolerated. Nevertheless, it has generally been the goal with refractive and/or cataract surgery to reduce-or at least not add to-those aberrations.

In summary, chromatic aberration is a fundamental property of IOLs. Techniques and methods of measuring and assessing the clinical effects of LCA are still being developed, but this pair of studies represent important steps forward in characterizing LCA in pseudophakic lens materials.

1.    Zhai Y, Wang Y, Wang Z, et al. Construction of special eye models for investigation of chromatic and higher-order aberrations of eyes. 

2.    Zhao H, Mainster MA. The effect of chromatic dispersion on pseudophakic optical performance. 

3.    Chang DH, Weeber HA, Lowery MD, Piers PA. Chromatic aberration of intraocular lenses measured in vitro and in vivo, ARVO 2016.

4.    Terwee T, Weeber H, van der Mooren M, Piers P. Visualization of the retinal image in an eye model with spherical and aspheric, diffractive, and refractive multifocal intraocular lenses.  

Dr. Chang is in private practice at Empire Eye and Laser Center in Bakersfield, CA. He is a consultant to Abbott Medical Optics.

White light is comprised of different wavelengths of visible light, ranging from red (700 nm) to violet (400 nm). As white light passes through an optical system, each of its component wavelengths bends independently.

Author | Daniel H. Chang, MD

Articles

Presbyopia: Rethinking approach to better meet patients’ needs

Troubleshooting post-presbyopia IOL complaints

Five secrets to success with co-management

What role does chromatic aberration play in IOLs?