The Keratoconus-Skin Condition Connection

HOT TOPIC

Study Finds Link Between Corneal Disease and Inflammatory Skin Conditions

An extensive and comprehensive review of data collected by the Baylor College of Medicine encompassing 19 countries and more than 165 million patients via the TriNetX Global collaborative network revealed a link between keratoconus and atopic dermatitis, psoriasis, seborrheic dermatitis, contact dermatitis, and urticaria.

This “real-world evidence approach” identified patients with keratoconus and then examined their medical history for any co-occurring inflammatory skin conditions. These variables were then controlled for demographic factors such as age, sex, race, and ethnicity. Atopic dermatitis was associated with a 2.27-fold increased risk of keratoconus development at 5 years, while patients with psoriasis had a two-fold increased risk. Seborrheic dermatitis, contact dermatitis, and urticaria were all associated with a 1.6-fold increase in developing the corneal disease. Rosacea showed no significantly increased risk of keratoconus.

The authors of the study, which was published in Cornea, believe that immune dysregulation and inflammation play a role in the connections, namely the inflammatory cytokines interleukin-1b, interleukin-6, interleukin-17, and the tumor necrosis factor alpha, which are all found with significant prevalence in the corneal tissue and tear film of patients with keratoconus and are extremely common in patients with psoriasis and seborrheic and contact dermatitis. The authors also suggest that “with appropriate index of suspicion and increased awareness of populations at heightened risk for keratoconus, it may be possible to diagnose patients with these conditions earlier in their disease course, potentially reducing complications associated with late-stage disease.”

My Two Cents

Fascinating. I have often wondered about these connections myself, and now we have some data to start connecting the dots. It makes sense if you think about it! We know that elevated cytokine levels promote inflammation and therefore will disrupt collagen crosslinking, which is essential when it comes to corneal consistency. The structural stability provided by corneal collagen crosslinking is likely why most patients don’t experience skin issues. As eye doctors, we know that a reduced amount of natural corneal crosslinking can lead to corneal thinning and ectasia. Meanwhile, our friends in dermatology understand that elevated cytokines in inflammatory skin conditions can cause a reduction in collagen structure and function. Crazy stuff! This might be a case where instead of the eyes being the window to the body, the skin is the window to the eye.

OUTSIDE THE LANE

Kids 13 and Under Should Not Use Smartphones—Here’s Why

CNN Health recently highlighted a fascinating study published in the Journal of Human Development and Capabilities, which revealed the detrimental effects of smartphone use on the mental health of children 13 years of age and younger based on self-reported data from nearly 2 million people across 163 countries.

The research, conducted by Sapien Labs, found that preteen smartphone use is linked to increased suicidal thoughts, worse emotional regulation, lower self-worth, and detachment from reality, with girls particularly affected. It also suggests that the earlier a child acquires a smartphone before 13 years of age, the worse their mental health outcomes, likely due to increased social media exposure, sleep disruptions, cyberbullying, and strained family relationships.

Lead author Tara Thiagarajan, PhD, emphasized the urgency of restricting smartphone access for children 13 years of age and younger and called for nuanced regulations to protect young users from the harmful effects of digital environments. Unlike prior studies focusing on anxiety and depression, this research explores less-studied symptoms such as emotional regulation and self-worth, revealing their significant impact. However, the study’s reliance on self-reported data introduces limitations, as responses were not independently verified and cannot specify which smartphone activities drive these outcomes or account for evolving technologies. The findings align with broader concerns about the adverse effects of early smartphone use, reinforcing recommendations from experts, such as social psychologist Jonathan Haidt, who advocates delaying smartphone access until 16 years of age. (Read more here.)

My Two Cents

“Doctor, when can I let my child have a smartphone? Play on their tablet? Etc.”

How often are we asked these questions as eye doctors? For me, it’s nearly every day. And from now on, my answer will be: “Recent studies show that the earlier a patient acquires a smartphone before age 13, the worse their mental health outcomes.” I’ll also be referencing the social psychologist’s recommendation of waiting until age 16.

CAN YOU RELATE

There are some absolute dynamos in the eye care field. We are fortunate to live in the age of Paul Karpecki, OD, FAAO; Ron Melton, OD, FAAO; and Randall Thomas, OD, MPH, FAAO, among countless others. However, we can’t forget our patient-turned-advocates, as in my opinion, they can (and should) be the most effective advocates for better health care. Exhibit A is Rebecca Petris, a dry eye/scleral lens patient–turned business owner of The Dry Eye Shop and passionate advocate of common sense reform in all areas of the ocular surface. She has been mentioned in the newsletter before as she continues to do amazing things!

Recently, Ms. Petris posted on her LinkedIn profile about some of the regulatory issues that have recently arisen regarding the OTC eye drop market. She goes in depth about the FDA's recent crackdown on marketing violations by OTC eye drop manufacturers, focusing on misleading claims about active versus inactive ingredients. She notes that the FDA's actions, particularly targeting newer European brands that have come to the United States, have caused these manufacturers to quickly adjust their marketing. However, she is disappointed that major US brands, which have been around for years and have long violated these rules, were not addressed first. These companies have, in many ways, normalized marketing that is somewhat confusing regarding active versus inactive ingredients, prominently advertising inactive ingredients as "key," which misleads consumers and obscures product comparisons. This has led to unclear drug fact labels, unlisted ingredient concentrations, and a lack of enforcement that has emboldened low-quality and potentially unsafe manufacturers, which, as we know, can lead to dangerous drops hitting the market unchecked! Ms. Petris further supports innovation in OTC eye drops but urges manufacturers to comply with FDA regulations, follow the monograph process for adding ingredients such as hyaluronic acid and trehalose, and stop blurring the line between active and inactive ingredients to protect consumers and restore clarity to the market.

This raises a critical discussion that needs to be had among industry, doctors, patients, and government representatives. It’s well past time for the FDA to reassess the rules for OTC drops. The lines have truly been blurred between what “active” ingredients are allowed and what exactly constitutes “key” ingredients. Heck, with some of the drops, it’s confusing to understand precisely why some “inactive” ingredients are considered inactive.

During a deep dive for this newsletter, I couldn’t even find a definitive answer to when the government last updated the rules for OTC drops. It appears that the final monograph for OTC ophthalmic drug products was completed in 1988, and a few amendments were made in June 2000. That’s all I can find. If anyone can provide further definitive data, please email me.

All that said, we need better transparency of exactly what the active, inactive, and key ingredients are in our drops. Perhaps, just perhaps, the FDA should reconsider its insistence on going above and beyond issuing glasses and contact lens prescriptions and instead focus on something that will genuinely improve the health and wellness of the American public. It’s clear they’ve given up on even attempting to regulate the online contact lens sellers—major kudos to Rebecca Petris for continuing to bring attention to this drop issue.

QUOTE OF THE WEEK

“No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth!”

— Ronald Reagan