#198 – Eye health—everything you need to know | Steven Dell, M.D.

“Do eye surgeons need to go to medical school? Yes, because we diagnose brain tumors. We find things that are systemic diseases that have ocular manifestations.”  —Steven Dell

Read Time 68 minutes

Steven Dell is an ophthalmologist, current Medical Director of Dell Laser Consultants, and a leader in refractive eye surgery with over 20 patents to his name. In this episode, Steven explains the anatomy and functional mechanics of the eye and how they relate to common variations in vision. He discusses changes in vision that occur with aging, the fundamentals of different types of vision loss, and provides an in-depth look into the various treatments and procedures available for corrective eye surgery. Additionally, Steven explains how one might protect the eyes and prevent vision loss—a topic particularly important for children in light of the epidemic of myopia.


We discuss:

  • Why Steven chose ophthalmology, and the crossovers to other medical disciplines [3:45];
  • Anatomy of the eye, common types of vision loss, and age-related vision changes [14:15];
  • Eye drops that can potentially improve vision [27:30];
  • The explanation for different eye colors [33:15];
  • Physiology of the eye and its connections to the brain [34:45];
  • Understanding human vision through an evolutionary lens [41:00];
  • Enhancing vision beyond 20/20 [47:00];
  • Astigmatism: definition, cause, and high prevalence [51:30];
  • Nearsightedness (myopia): causes, epidemic in children, and prevention strategies [54:15];
  • Cataracts: impact of aging and how they can be repaired [1:05:00];
  • Lens implants that can correct and improve vision [1:19:30];
  • Effects of eye trauma [1:26:45];
  • Corneal abrasion from ‘dry eye’: causes, treatment, and prevention strategies [1:29:00];
  • Sunglasses for eye protection [1:35:00];
  • Solutions to correct nearsightedness [1:42:00];
  • Laser eye surgery—photorefractive keratectomy (PRK) [1:45:45];
  • Laser eye surgery—LASIK [2:02:00];
  • Laser eye surgery—small incision lenticule extraction (SMILE) [2:11:45];
  • Glaucoma: definition, causes, symptoms, and care [2:13:45];
  • Tips for preserving eye health [2:20:00];
  • Screen time and eye health [2:24:15];
  • Contact lenses: good hygiene and considerations [2:27:45];
  • A bonus benefit from repairing cataracts [2:29:00];
  • Questions about corrective eye surgery [2:31:30];
  • How an eye exam can be a window into metabolic illness [2:33:45]; and
  • More.


Why Steven chose ophthalmology, and the crossovers to other medical disciplines [3:45]

  • The eye is a topic that everybody has questions on, Peter included 
  • From medical school, Peter remembers there is an optic nerve, a cranial nerve, and the second cranial nerve (this is the optic nerve)
    • He remembers something called fovea, and he knows there’s a blind spot, but he’s forgotten why
  • Peter remarks, “It’s safe to say my knowledge of this topic right now is probably at par with everybody’s right?” 
  • Steven understands, “Well, that’s not rare, frankly, because the eye is so literally compartmentalized. We just don’t interact that much with other specialties, so it’s not rare for people who are in other specialties to be very ignorant of the eyeball, and that’s fine because I think it’ll help us keep the level of discussion at an approachable level for everyone.” 
  • Peter asks if there has ever been discussion suggesting that ophthalmologists don’t need to do the four-year MD degree
    • How much of what was learned in medical school became relevant in residency?
  • Steven says there was quite a lot
    • There’s nothing specifically magical about the eyeball
    • It’s got neurological tissue in the back, actual brain tissue in the back
    • It’s got a vascular supply
    • There are a lot of crossovers to other medical disciplines
    • All of the cellular processes are the same
    • He operates adjacent to the eye
  • He thinks it’s important for ophthalmologists to have a general sense of medical knowledge, particularly because so many systemic diseases manifest as eye problems
  • Now there is a discipline of medical training or of visual training, basically optometry— which deals with the eye, but not all of the surgical stuff
  • He works in a collaborative fashion with optometrists
    • Those are the folks who are fitting glasses
    • They’re screening for eye disease
    • They’re handling preoperative and postoperative care in many cases
    • They’re treating some diseases that are specific to the eye, such as glaucoma

Ophthalmology training

  • Peter asks about ophthalmology residency— does everyone spend time operating?
    • Is there a nonsurgical discipline to this?
    • Does the training bifurcate?
  • Steven explains, “There are nonsurgical ophthalmologists, but I think they all start out as surgeons to become an ophthalmologist. You’re really training to become an eye surgeon.” 
    • But there are, for example, neuro-ophthalmologists, which are really more neurologists than eye surgeons; they don’t do eye surgery
    • There are some ophthalmologists who don’t do eye surgery
  • Peter recalls one of his lasting memories from residency was stealing suture from the ophthalmology OR at Hopkins 
    • As the number of the suture gets larger the suture itself gets smaller
    • An O suture is thick, like a piece of rope
    • The scale progresses from 1-0, 2-0, 3-0, etc
    • By a 4-0 suture, it’s actually quite thin
  • Steven replies they use an 11-0 suture
  • Cardiac surgery uses a 7-0
    • Occasionally there’s some guys that would sew the distal end of a coronary artery with an 8-0 and at that level, it’s already very thin; just the slightest tug too much, and it breaks
  • Peter recalls about ophthalmology, “you guys wrote 11-0, and so I used to steal 11-0 constantly every night I was on call and practice suturing with 11-0. The thinking being, if you can tie in 11-0 with your hands and not tear it, that 7-0, which normally is like a piece of hair is going to feel like a piece of rope. I used it to help me develop a good feel for fine suture” 
  • The tools in ophthalmology are tiny and Steven can remember the operating room where he did his training was near orthopedic surgery 

You hear this Black and Decker stuff going on over there, and our little tiny tools are very, it’s just totally different” – Steven Dell 

  • Everything he does operationally is under a microscope
    • They use a binocular microscope
    • So he’s looking through both eyes, and this is either mounted from the ceiling and is controlled by his feet
      • The X, Y, and Z, and the zoom focus are controlled by a foot pedal
      • And that either comes from the ceiling or it’s on a really large stand
  • He’s sitting and looking straight ahead, so the image is here, but he operating down below
    • It’s interesting because sometimes his wife will kid him, I’ll come home from a day of surgery exhausted, but she says something like, “well, I don’t really get it. You’re just sitting in a chair, making these little tiny movements, and there’s soft music playing. It all seems very, very sedate.” 
    • It’s incredibly stressful and exhausting
  • Ophthalmologists  have a problem where they tend to hyperextend
    • They tend to bring their head forward, to come up to the oculars and that creates a whole other set of problems
    • There are ergonomic challenges for sure, and he remembers early on in his career, he was coached very carefully on how to sit, how to have his spine arranged
      • One doesn’t want to crane their neck forward
      • He  has to make sure his shoulders are down
    • Steven notes, “It’s interesting because when you train surgeons, and you look at them, they’re all raising their shoulders up, and they’re terrified that they’re going to do something wrong. They’re in a very, very compromised and stressful position, and then they tend to lift their hands up.” 
    • The surgical movements are these little tiny movements, so very small positional changes can have a huge impact on the outcome of the surgery
  • Peter understands this problem, he has 2 friends from residency who required multiple neck surgeries
    • One of them could no longer operate after his surgery; he trained as a cardiac surgeon and now does cardiac critical care
      • It’s still a great career, but after 10 years of training as a cardiac surgeon, to not be able to operate…
  • Peter asks if Steven knew he wanted to do ophthalmology when he began medical school
  • No, but he knew he wanted to do something surgical, something with his hands
  • He remember a Eureka moment where the first time he looked through a slit lamp (which is basically a microscope to look into the eye) he was hooked
    • This was during an ophthalmology rotation in a weeks where they did a little  ophthalmology and a little ear, nose, and throat
    • It was then that he knew ophthalmology was what he wanted to do
    • He had some exposure to ophthalmology prior because the father of one of his friends was an ophthalmologist
  • Peter asks if ophthalmologists do a general surgery internship
  • Some do; Steven did what is referred to as a transitional residence internship, where one does a little bit of everything: general surgery, internal medicine
    • It was very helpful
    • The general surgery part was rough, but it was nice to have exposure to a little bit of everything
  • It was a 4-year residency, including the internship
  • Peter asks what was the “bread and butter”?
    • For example, in general surgery in the 1960’s and 1970’s, it would’ve been Billroth procedures and things like that, where the most common thing one was doing was cutting out half of the stomach because of peptic ulcer disease and things like that
    • By the time he got to residency, he never did one of those because H2 blockers and PPIs basically eliminated the need to surgically remove part of the stomach for gastric or peptic ulcers
  • Peter wants to know, at the time of his training, where did 80% of the volume come from? What type of cases?
  • It was cataract surgery and then retinal disease
    • It’s still cataracts
    • The scourge of essentially diabetes causes these very, very complex retinal problems


Anatomy of the eye, common types of vision loss, and age-related vision changes [14:15]

  • When Steven explains the eye to a kid, he compared it to a camera with film in the back; that’s the retina
    • Then the kid looks at his parents and asks, “What’s a camera? Film, what’s that?” 
  • The eye is built like a camera where in the very front is the cornea
    • The cornea is the covering on the front of a watch; that’s the thing that a contact lens would sit on

Figure 1. Anatomy of the eye.  Image credit: Kellogg Eye Center

  • The next thing is the pupil, which is the hole in the iris

{end of show notes preview}

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Steven Dell, M.D.

Steven Dell is a board certified ophthalmologist in Austin and the Medical Director of Dell Laser Consultants.  He is an internationally recognized leader in refractive eye surgery specializing in: LASIK laser eye surgery, cataract surgery and refractive lens exchange.  He is the chief Medical Editor of the medical journal Cataract and Refractive Surgery Today.  He is the Chair-emeritus and President-emeritus of The American-European Congress of Ophthalmic Surgery.  He is a principal investigator for a variety of FDA clinical trials in the field of eye surgery.  He has invented several surgical instruments and devices, and holds over 20 US and international patents in eye surgery including the: Dell Astigmatism Marker™, Dell Fixation Ring™, Dell PlumeSafe Ophthalmic Evacuation System™,  and Dell PlumeSafe Handpiece™.  He is also the author of numerous textbook chapters and peer-reviewed journal articles. [Dell Laser Consultants]

Disclaimer: This blog is for general informational purposes only and does not constitute the practice of medicine, nursing or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this blog or materials linked from this blog is at the user's own risk. The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard, or delay in obtaining, medical advice for any medical condition they may have, and should seek the assistance of their health care professionals for any such conditions.
  1. overall good discussion But Dr. Dell mentioned that there is Not increased glaucoma in diabetic patients…..this is clearly wrong….it is well known/documented that diabetic patients have increased risk/occurrence of glaucoma….thanks, Chet Roe MD

    • You’re absolutely correct! I noticed that today when I watched, gulp… Thanks for pointing this out.

  2. I remember in the beginning of my nursing career I worked at CHOC (the old building) 5th floor as a CNA. It was a med-surg/neuro floor and we would frequently need neuro consults. I can’t for the life of me remember his name but we had this amazing Neurologist that would do these ad hoc inservices (usually when we had an unusual admit) and we were (nursing staff) amazed by what he could determine from a simple assessment of visual field errors in relation to lesion size/locations.

  3. Eye opening, to say the least. So much helpful information, especially about the dangers of not playing outside and too much screen time for children. Reduced my anxiety about future cataract surgery. Enjoyed the story about the English doctor who treated RAF pilots and later figured out how to make the first plastic lens. Thank you so much for this valuable and interesting information.

  4. Wow 10/10. Please do this with every organ, including the appendix, if only to say it’s useless.

  5. Excellent conversation. Dr. Dell speaks eloquently and explains the topics clearly and informatively. I learned a lot. I also appreciated Peter’s millions of questions so that the discussion is quite clear. Thank you both. you guys rock!

  6. Thanks for this conversation. It confirmed for me that I’m on the right track when I send my kids out to play for long stretches of time even if they moan and groan about it.

    I wonder if any research has been done regarding association between tension in the muscles that move the entire eyeball and corneal astigmatism?

    I’m a 42 yo man and have had better than 20/20 vision for most of my adult life. About 5 years ago I developed a mild astigmatism in the left side of my left cornea (diagnosed by an optometrist). It’s not yet at the point where it needs a corrective lens. When I meditate and bring full awareness to my facial muscles I often feel tension stored more in some muscles than others, and relaxing takes time and effort.

    I also sometimes perform eye “exercises” where I hold my head steady pointing forward and then look as far laterally as possible to one side then the other and do several reps like this. Then I do a few reps up and down with the eyes. Once I’ve done a few sets I’ll try to relax my eyes and stare into the distance. I find if I’m consistent with both the relaxation practices and the eye movement exercise the astigmatism is less noticeable. If I spend a few days with lots of close work and fail to do my little routine it seems to worsen.

    My hypothesis is that the lateral muscle of my left eye holds tension within itself more than my other eye muscles, and this has distorts the shape of my eye to the point that it affects my cornea. I know when I get a massage I often have unequal tension held on one side of my spine or the other… Is there anything to this idea or am I off in la-la land?

  7. Great topic, super-interesting and informative. As we all age and heading towards almost inevitable cataract formation, I’m really interested in bifocal/trifocal artificial lens insertion for prevention of cataract and for correcton of my myopia and presbiopia at the same time.
    A question for Dr. Dell: what are the most common side effects of this surgery ? All I could find in litterature was retinal detachment, but what is its percentage ? Would much appreciate a link to a recent data on this type of surgery if available.
    Huge Thanks for this episode Peter!

  8. Wish you covered being able to diagnose Alzheimer’s through an eye exam. Great content as always and Dr Attia you are a genius and a science rockstar. Thanks for helping us regular folks.

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