With the weight of surgeon experience and (good) evidence behind the idea that pupil size does matter in laser vision correction (LVC), why are LVC-casualty lawsuits in which pupil size is a central issue still returning defense verdicts? (A defense verdict means the jury decides in favor of the doctor.) The Lone Dog sighs, scratches, and ruminates on the power of the corporate checkbook. There are refractive surgeons aplenty who will testify as expert witnesses that pupil size is irrelevant to the outcome of LVC. If this argument won't work, they blame spherical aberration. This article is going to address the pupil size issue.

First, what is the doctor's duty to you as a patient? The Law defines this in varied, and often surprising, ways. Ways that no ordinary human can comprehend. However, there is a generally accepted idea that you should know what you are getting into. This is embodied in the process of informed consent. Informed consent is not a piece of paper; it is an educational activity that provides you, the patient, with information that a reasonable person would want to know about the risks of a certain procedure or treatment. If the risk of death from toenail surgery is 1 in 1 million, the doc is not required to talk you through every possible risk from "expect some bleeding" through to "death". He can stop at "your toe might drop off". Sometimes the reasonable-person cutoff gets a little fuzzy, and the jury has to think for itself.

A reasonable person would want to know the risks of any operation as they apply in his specific situation. There may be something about you in particular, as opposed to LVC patients reported in studies, that changes the likelihood that you will suffer a particular complication or develop certain known permanent side effects. In the LD's (non-legal) humble opinion, you have the right to be informed of your risks. Your doctor, Joe Surgeon, has examined your eyeballs, presumably. He should be able to tell you something about you in particular. If the best he can manage is to quote statistics from the laser's User Manual, you and he should fervently hope that you resemble the patients described therein to a very high degree. If you are comfortable with fervent hope as a basis for eye surgery, go ahead.

Let's digress briefly onto the topic of Terrible Science. Terrible science is frequently encountered in the LVC arena. Typical study design errors include (1) not describing what types of patients were studied in enough detail to determine if the research applies to a particular patient like Lou "Big Pupil" Schmo, (2) not caring what types of patients were studied as long as they had some form of LVC, (3) selection bias, i.e., including only very-low-risk-extremely-likely-to-be-happy patients, (4) very small numbers of patients, (5) very short follow-up after surgery, (6) relative, as opposed to absolute, outcome measurements, e.g., starbursts are "better".

There is a particularly rich lode of terrible science on the topic of pupil size, ablation size, and the risk of side effects after surgery. Much of it was paid for either directly or indirectly by the corporate checkbook. Often, every single one of the investigators had a financial conflict of interest. This "science" is often first piloted in monthly junkers like EyeWorld, Ocular Surgery News, and Ophthalmic Times. Lots of it never makes it into any peer-reviewed journal. Defense attorneys still manage to use this research to make the following arguments.

Fixed Zone Laser Platforms

"Fixed" means that there are one or two options for optical zone diameter.

The lawyers will tell you that:

1. Ghosts, arcs, starbursts, and halos (GASH) in dim light are known side effects of LVC (not complications).

2. The likelihood that you will get GASH is not related to the size of your pupils in the dark (reference the terrible science here).

3. It doesn't matter that the vast majority of textbooks on LVC emphasize that patients with larger pupils have an increased GASH risk.

4. It doesn't matter that a major review article in Survey of Ophthalmology, an eminent, peer-reviewed, international publication that typically summarizes years or decades of work on a particular topic, unequivocally states that a mismatch between pupil size and ablation size is related to the likelihood of GASH.
   [Melki SA, Azar DT. LASIK Complications: Etiology, Management, and Prevention. Surv Ophthalmol. Volume 26 (Sept), 2001. Pages 95 — 116.]

5. Therefore, it doesn't matter that your surgeon measured your pupils wrong, because pupil size is irrelevant, because our expert witness says so. So it doesn't matter that our laser couldn't have made an optical zone "big enough" for you anyway.

6. He told you GASH could happen, GASH did happen, you have no case.

7. Further, it doesn't matter than you would have made a different decision had you been specifically informed of the increased risk of GASH when you have 7.5 mm pupils and the surgeon performs a 6.0 mm optical zone ablation.

8. Also, it is your fault that you didn’t know enough to ask about pupils and ablation zones and all that stuff before you agreed to the surgery.

9. Also, it is your fault that, even though you did know about it and did ask about it, you decided to go ahead. It is irrelevant that you were told that you had 6.0 mm pupils and would have a 6.0 mm optical zone, which sounded all right to you. It is further irrelevant that you actually have 7.5 mm pupils since it doesn't matter anyway.

10. Get it?

The LD sighs particularly deeply when thinking about VISX and GASH. Truly, there are many people treated on VISX lasers of various generations, whose pupil size in the dark is larger than their optical zones or even their total ablation zones, who do not have GASH. They don't. They aren't lying or stupid. VISX offers 6.0 and 6.5 mm optical zones, and 50% of the LVC-age population has pupil diameters of 7 mm or more in the dark. But because much of their science on the topic of pupil size and vision quality was methodologically terrible, and then the data was frappéd into a tasty blend, VISX and its surgeon flunkies (excuse me, consultants) have thus far been unable to identify in any detail what it is about these patients that makes them lucky and happy. Or if they have they aren't saying. So there you are with your 7.5 mm pupils, trying to decide whether to have surgery. And your surgeon cannot answer these questions: Am I more like the happy big-pupil patients? Am I more like the unhappy big-pupil patients? What's the definition of "like", anyway? Age, gender, iris color, corneal curvature, corneal thickness, flap thickness, length of eyeball, attempted correction, distance between the eyelids? After "millions and millions treated", could we have some data please?

Variable Zone Laser Platforms

"Variable" means that the optical zone can be programmed in small increments (such as 0.5 mm) up to fairly large sizes (such as 7 mm or larger). This gives the surgeon the option to select an optical zone that is larger than the patient's maximum low-light pupil diameter. [Note that there are other safety considerations when using large zones.]

This is what their lawyers have to say:

1. Ghosts, arcs, starbursts, and halos (GASH) in dim light are known side effects of LVC (not complications).

2. We know that the vast majority of textbooks on LVC emphasize that patients with larger pupils have an increased GASH risk.

3. We have developed a wonderful laser that can make an 8.0 mm optical zone.

4. It's too bad that your surgeon measured your pupils wrong and made your optical zone 1.0 smaller than your pupils, when it could have safely been 1.0 mm larger than your pupils.

5. He told you GASH could happen, GASH did happen, you have no case.

6. It doesn't matter that you learned about pupil size and optical zones beforehand, and chose to proceed on the specific understanding that our laser could make your optical zones larger than your pupil size in dim light.

7. Anyway, your problem is due to spherical aberration which can happen to anyone, therefore the 1.0 mm mismatch is irrelevant, because our expert says so.

8. Besides, the 5.5 mm optical zone is the FDA-approved size. We actually designed and marketed the laser as a large-zone laser just for fun. It was a thought exercise. The 5.5 mm zone* is perfectly all right for everyone.

9. Get it?

   *FDA-approved for nearsightedness with astigmatism on the Alcon LADARvision laser. No other zone size is approved, which is why the Alcon LADARvision web site doesn't mention this awesome feat of engineering.

The Lone Dog's Idea of a Really Terrific Informed Consent Conversation #1

Featuring Lou "Big Pupil" Schmo and Joe "Honest Joe" Surgeon.

Joe: Lou, you have 7.5 mm pupils in the dark. The VISX optical zone goes up to 6.5 mm and the blend zone around it increases the total treatment area to 8.0 mm. You are not that nearsighted (-3 diopters) and you don't have any astigmatism, so when VISX says 6.5 that's actually what you'll get. Also, your corneas are thick enough that we can give you the full 8.0 mm treatment. You should be prepared to have some GASH after surgery. I can't give you an exact number and I can't honestly tell you "how bad" it will be. But I notice that you are currently wearing toric contact lenses and your glasses are pretty out of date, and you tell me that you have some blurring and starbursts at night now. You may be someone who is functionally OK with GASH that is not worse than what you have now anyway. I know you heard about me from Frank, who is super happy. You are not like Frank in some important ways, so you should not assume that you will automatically end up like Frank, because some of your risk factors are a little higher than his.

[The LD delivered this soliloquy a few times, and it took about 5 minutes max, talking slowly, backing up, and pointing to diagrams.]

Lou: Holy moley you are the most honest refractive surgeon I have ever met. I am going to think about this some more, but I trust you to do the right thing and give me the best chance to have a good outcome by making surgical decisions that will minimize the likelihood and severity of GASH. I think I will probably go ahead. I would like to take the consent form home with me and read it, plus study the notes I have taken during this conversation and surf the web some more. I think I would like another pre-op visit, and I will come prepared with a list of questions.

Joe: Terrific.

The Lone Dog's Idea of a Really Terrific Informed Consent Conversation #2

Joe: Lou, you have 7.5 mm pupils in the dark. The VISX optical zone goes up to 6.5 mm and the blend zone around it increases the total treatment area of 8.0 mm. You are fairly nearsighted (-7 diopters) and you have significant astigmatism (2 diopters), so when VISX says 6.5 you don't actually get that. Your treatment zone will be oval shaped, and the short dimension will be substantially smaller than your pupil size. Even the long dimension of the oval will not be correcting your full -7 diopters over the total 6.5 mm. I notice that you have worn gas perm contact lenses for years and you have no starbursts or halos around lights when you drive at night. You are at substantial risk to develop GASH after surgery. I can't give you a hard number, but remember that if it happens to you it is 100%. You may or may not find the GASH to be a problem in your life, or consider it an adequate trade-off to get out of contacts. I have treated many patients like you and most are happy overall and tell me they would do it again. But this includes a fair number of patients who already had GASH at night. So you need to know yourself, and how bothered you might be by sub-normal vision quality under some circumstances. If the whole idea freaks you out or you don't want to gamble on being "OK" with some unknown level of GASH, which you have never experienced up until now, you should not have surgery at this time.

Lou: You are the most honest refractive surgeon I have ever encountered. I am an engineer and little things bother me a lot. I will call you once a year to find out if technology has advanced to the point that I would be a better candidate than I am now for LVC.

Joe: Terrific.

The LD thought about writing up a few Really Terrible Informed Consent conversations, but then realized that the web was already crammed with them, as reported by actual LVC casualties. They would be almost unbelievable except that they're true. These LVC casualties are not impulsive, unintelligent people. They had no more understanding of the workings of LVC than the LD does of jet propulsion; they trusted their surgeons (1) to educate them about their surgical risks so they could give informed consent for themselves, and (2) to plan and execute the treatment in a fashion that would minimize the likelihood and severity of GASH or other complications. It is not normally expected that a patient with gallstones understands gallbladder surgery in any detail. Why is there an evolving higher standard for LVC? The LD doesn't know.

[Note from the LD: The Informed Consent conversations focus on VISX-type issues because VISX is the most frequently used platform in the USA, plus it's an easy assault. There are also important subtleties to the optical zone numbers "6.0 mm" and "6.5 mm" that the LD wanted to clue you in about. Alcon is another matter since the laser is designed to deal with larger pupil sizes by offering larger optical zones "off-label". However, it's no good to you if Joe Surgeon doesn't use that capability when it would be indicated, and then pretends it wasn't important to begin with. VISX and Alcon should not take this personally. Other laser companies should not feel smug. Also, with all lasers there is the question of what you paid for versus what you got in terms of the size and quality of the ablation.]