Dr. Bruce Nguyen OD ♥ Oct 08, 2023.
INTRODUCTION
“When you turn toward the sunshine, the shadow falls behind you” Hellen Keller.
There are no doubts in my mind that human beings are programed to love spending time outdoors. It is in our DNA. Yet, we know that too much sun can be harmful to our body, especially our skin. You probably know that too much UV exposure can cause skin cancer.
But did you know that 10% of skin cancer occurs around the eye? Why? It’s because no one ever puts sunscreen around their eyes.
Or too much syn exposure can cause your eyes to turn yellow over time?
To protect our eyes, it is very important to wear quality sunglasses, wide-rim hats, and limit our time in the sun.
In eyecare and in healthcare, an ounce of prevention is worth more than a pound of cure. Keep on reading to learn more about how the sun affects your eyes.
A YELLOW BUMP ON THE EYE IS TYPICALLY A PINGUECULA
The first thing I notice about my patients is their eyes color. You may think, “Me too”, but I am not talking about typical colors of the iris, the brown or hazel or blue that we tend to use to describe someone’s eyes.
Rather, I am talking about the yellow bumps on the eye, aka pinguecula.
Pinguecula, pronounced as {ping·gweh·kyuh·luh}, is a raised, yellowish bump on the conjunctiva, near the cornea. The conjunctiva is the translucent shiny layer on top of white scleral. The pinguecula is formed after prolonged exposure to any ocular irritation, such as UV rays, dirt, and wind.
The make-up of the pinguecula is often protein, fat, and deposits. In a way, it is like a callus on your hand.
PINGUECULA IS TYPICALLY CAUSED BY TOO MUCH SUN
Pinguecula is common. According to the National Center for Biotechnology Information (NCBI), the percentage of people with pinguecula can range from 22% to 97%, depending on where you live.8 I know it is very common where in the beautiful city of San Diego, California where I live and work. I literally have “the sunglasses talk” with my patients every day.
Pinguecula is associated with aging, trauma to the eye, wind, dust, sun exposure, especially sun exposure. It is a common finding in people who spend a significant time outdoors. In one study, eye doctors examined 394 post office employees and found that 63% of them have pinguecula.6 Given the occupational nature of mail persons, it is not surprising that so many of them have pinguecula.
PINGUECULA vs. WELDING & BAKING
And it is not just the sun. Welding also has a link of association with pinguecula, so does cooking with ovens. In one study, researchers found that more than 50% of welders have pinguecula.10
In another study, researchers showed that “pinguecula is strongly associated with exposure to tandoor ovens.”9 The oven used in this study is a common type of oven called tandoor oven.
“A tandoor oven is a cylindrical clay oven used to make flat bread or to cook meat especially in Azerbaijan, India, Turkey, Iran, Armenia, Pakistan, Uzbekistan, and Afghanistan. The heat for a tandoor oven is traditionally generated by a charcoal or wood fire, burning within the tandoor oven itself, thus exposing the food to live-fire and radiant heat cooking.”9.
PINGUECULA vs. ALCOHOL CONSUMPTION
Interestingly, in another study in Spain, researchers found a strong positive link between alcohol consumption and pinguecula.7 Who knew?
Should you stop drinking your favorite alcoholic beverage because of this finding? Up to you but I know I’m not.
Oxidative stress from alcohol seems to be the contributing factor to pinguecula formation.7 Here are the summary findings of the study.
PINGUECULA & CONTACT LENS WEAR
Being an eye doctor who specializes in fitting specialty contact lenses for myopia management (OrthoK Overnight lenses) and scleral contact lenses to treat keratoconus, I am naturally curious about the effects of contact lenses on pinguecula.
But what are the actual research results on the effects of contact lens wear and pinguecula? The findings are mixed. I can find only two studies on the specific subject of contact lenses and pinguecula.
The first study found that “pinguecula could be one of the complications related to wearing CLs”11. This study includes both hard and soft contact lenses wearers and the severity of the pinguecula associated.
The researchers hypothesized that the pinguecula formation may be the result of the constant rubbing of the contact lens edges against the conjunctiva upon blinking. Given that an average human blinks between 15-20 times a minute to the equivalent of 15,000 to 20,000 times a day, the result makes intuitive sense.
You can see the summary below.
In the second study, researchers found no correlations between soft contact lenses wear and the likelihood of having pinguecula.12 Note that this study does not includes hard contact lenses.
SO, SHOULD YOU WEAR CONTACT LENSES WITH A PINGUECULA?
Medicine is an art, and a doctor must continually weigh the evidence of research to come up with the right treatment plan, given what he or she knows about the disease at that point in time.
A constant thirst for knowledge, a mixture of professional curiosity and skepticism are the two pillars of a good doctor’s character. The other two pillars are honesty and integrity.
My clinical experience leans heavily on the opinion that contact lens wear is an important risk factor for pinguecula. Until there is new evidence pointing the other way, I will practice under the conservative assumption that there is a link between contact lens wear and pinguecula, and it is a negative one.
After, all of us were born naked, and none of us were born with pieces of fancy plastic stuck under our eyelids. It is hard to imagine our DNA being able to re-write itself so quickly to adapt to the rapid evolution of our technology in wearable medical devices such as contact lenses.
YES, YOU CAN WEAR CONTACT LENSES WITH PINGUECULA, BUT FOLLOW THE 5-10 RULE
Medicine is an art, and a doctor mus
At my practice, I always recommend that my contact lens patients follow the 5-10 rule of contact lens wear: 5 days a week, 10 hours a day and wear glasses the rest of the time.
I designed the 5-10 rule to maximize the balance between eye health and visual need of a contact lens wearer.
The rule may be slightly different depending on what type of contact lens you are wearing. If you are wearing scleral contact lenses for keratoconus treatment, your wear schedule will be different than someone who is wearing overnight Ortho K lenses for myopia management.
However, the main idea here is that moderation in contact lens exposure goes a long way in supporting healthy eyes in the long run.
t continually weigh the evidence of research to come up with the right treatment plan, given what he or she knows about the disease at that point in time.
A constant thirst for knowledge, a mixture of professional curiosity and skepticism are the two pillars of a good doctor’s character. The other two pillars are honesty and integrity.
My clinical experience leans heavily on the opinion that contact lens wear is an important risk factor for pinguecula. Until there is new evidence pointing the other way, I will practice under the conservative assumption that there is a link between contact lens wear and pinguecula, and it is a negative one.
After, all of us were born naked, and none of us were born with pieces of fancy plastic stuck under our eyelids. It is hard to imagine our DNA being able to re-write itself so quickly to adapt to the rapid evolution of our technology in wearable medical devices such as contact lenses.
SO DOC, WHAT CAN I DO ABOUT MY PINGUECULA?
“There are things which are under our control, and there are things which are not under our control” Epictetus, ‘The Enchiridion.’
We know pinguecula is related to sun exposure, trauma, heat effects, wind, dust, and aging, and contact lenses wear. Among these, the things under our controls are as followed:
When outdoors, limit your sun exposure.
o Wear quality sunglasses. Not all sunglasses are the same. Get the good one and don’t lose them.
o Wear a wide-rim hat.
o Wear clear UV-blocking lenses if sunglasses are not an option at work or home.
o If you wear prescription glasses, make sure the lenses are photochromic lenses, i.e., lenses that change from clear lenses indoor to sun lenses outdoor.
In the kitchen
o Understand the effect of heat on pinguecula.
o Wear clear lens protection if possible.
When wearing soft contact lenses
o Follow the 5-10 rule: Only wear contact lenses 5 days a week, 10 hours ago. The rest of the time wear glasses.
o When you go home from work, and change into something more comfortable, change from contact lenses to glasses.
o Use rewetting eyedrops made specifically for contact lenses 2-4 a day. My favorite brand is Blink for Contact.
When wearing specialty contact lenses
o If you wear OrthoK overnight lenses or other lenses for myopia management, follow your doctor’s advice.
o If you wear scleral contact lenses for keratoconus management, understand that having pinguecula makes it more difficult for your doctor to achieve a good fit of contact lenses.
o Advance technology such as computerized corneal imaging will increase the likelihood of successful lens fit.
o When you look for a keratoconus specialist who specialize in fitting scleral contact lenses, ask about Eye Surface Profiler technology such as the Eaglet™ like the one we use in our office. Such technology essentially makes a virtual mold of your eyes, pinguecula and all, to create a personalized fit that is well-fitting and comfortable, all by using data captured by the machine.
Special consideration for outdoor occupations such as landscaping or agriculture
o Considered a wrapped, polarized sunglasses with moisture-seal chamber by utilizing removable gasket. Those do a better job of protecting your eyes from the constant wind and dust. A good brand of sunglasses with moisture-seal chamber is Wiley X.
o Use rewetting eyedrops throughout the days to wash away debris and rehydrate your eyes.
Special consideration for children
Children are more susceptible to UV damage to the eyes because their eyes are more fragile and their pupils are also larger, allowing more UV rays to pass through, reaching the retina.
It has been estimated that up to 80% of the UV damage done to a person’s eyes occurred before the age of 18.5.
Therefore, it is vital for parents to make sure their kids wear sunglasses, photochromic lenses, or clear UV-blocking lenses every day.
And the sooner they start, the more protected their sensitive eyes will be from the damaging rays of the sun.
PINGUECULA & PTERYGIUM AKA SURFER’S EYE
A pterygium is essentially a pinguecula on steroid while doing 200 mph on the highway to miserable eye’s hell. Pterygium is also known as surfer’s eye or farmer’s eye.
A pinguecula limits its growth to the white part of the eye. A pterygium not only grows on the white area, but it also invades the clear dome-shape of the eye called the cornea and causes an increase in corneal astigmatism.
In appearance, pinguecula presents as small yellowish bumps, while pterygium is often angry-looking and large, wedge-shaped tissue covering part of the cornea.
You can see the difference between a pinguecula and a pterygium in this wonderful illustration by my all-time favorite nine-year old artists, aka my daughter.
There are, of course, more distinctive morphological characteristics differences between the two. The treatment protocols are also different. However, most differences are only interesting from a doctor’s perspective. From the patient’s perspective, it is just a pinguecula that had advanced significantly.
Here is what a pterygium looks like in real people.
WHAT CAN I DO ABOUT MY PTERYGIUM?
Most of the points discussed above about pinguecula applied to pterygium as well. The critical point to remember is that if you have pinguecula and you take all the precautions outlined above, the chance that your pinguecula progress to pterygium is significantly reduced.
One significant difference between pterygium and pinguecula is the ability to wear contact lenses.
With pterygium, comfortable contact lenses are clinically difficult due to the nature of the condition. However, there are surgical options to remove the pterygium, restore a normal appearance to the eyes.
Once the pterygium is removed, contact lens wear is a viable option once more.
CONCLUSION
In summary, it is vital to our eyes’ health to wear quality sunglasses, wide-rim hats, and limit our time in the sun.
Pinguecula is common and visually displeasing, but we can take steps to prevent it from getting worse.
Contact lens wearers should follow the 5-10 rules.
And pterygium can always be removed surgically if need be.
Finally, in eyecare and in healthcare, an ounce of prevention is worth more than a pound of cure.
Dr. Bruce Nguyen practices in San Diego, CA. He specializes in myopia management in children. He treats keratoconus with scleral lenses, and he also manages dry eyes with advanced technology like IPL (Intense Pulsed Light Therapy) and RF (Radio Frequency) for advanced dry eyes relief.
Photo Credits
1.Woman in Sunglasses and Hat Image by halayalex on Freepik
2.Two Happy kids in sunglasses by user15285612 on Freepik
References
1. Eyelid and ocular surface carcinoma: diagnosis and management. Yin VT, Merritt HA, Sniegowski M, Esmaeli B.Clin Dermatol. 2015 Mar-Apr;33(2):159-69. doi: 10.1016/j.clindermatol.2014.10.008.
2. Correlation of Sunlight Exposure and Different Morphological Types of Age-Related Cataract. Li X, Cao X, Yu Y, Bao Y.Biomed Res Int. 2021 Nov 12;2021:8748463. doi: 10.1155/2021/8748463. eCollection 2021.PMID: 34805407
3. Moan J, Grigalavicius M, Baturaite Z, Dahlback A, Juzeniene A. The relationship between UV exposure and incidence of skin cancer. Photodermatol Photoimmunol Photomed. 2015 Jan;31(1):26-35. doi: 10.1111/phpp.12139. Epub 2014 Oct 13. PMID: 25213656.
4. Ivanov IV, Mappes T, Schaupp P, Lappe C, Wahl S. Ultraviolet radiation oxidative stress affects eye health. J Biophotonics. 2018 Jul;11(7):e201700377. doi: 10.1002/jbio.201700377. Epub 2018 Apr 24. PMID: 29603665.
5. Tang FC, Chen SC, Lee HS, Lin WF, Chou MC, Lee MC. Relationship between pterygium/pinguecula and sunlight exposure among postmen in central Taiwan. Zhonghua Yi Xue Za Zhi (Taipei). 1999 Aug;62(8):496-502. PMID: 10462825.
7. Viso E, Gude F, Rodríguez-Ares MT. Prevalence of pinguecula and pterygium in a general population in Spain. Eye (Lond). 2011 Mar;25(3):350-7. doi: 10.1038/eye.2010.204. Epub 2010 Dec 24. PMID: 21183945; PMCID: PMC3178324.
8. Somnath A, Tripathy K. Pinguecula. [Updated 2021 Aug 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK558965/
9. Gul, A., Goker, H., Sabanci, S., Kurt, A., & Turkyilmaz, K. (2014). Relationship between pinguecula formation and exposure to tandoor ovens in a hospital-based study. International journal of ophthalmology, 7(6), 1014–1016. https://doi.org/10.3980/j.issn.2222-3959.2014.06.19
10. Norn M, Franck C. Long-term changes in the outer part of the eye in welders. Prevalence of spheroid degeneration, pinguecula, pterygium, and corneal cicatrices. Acta Ophthalmol. 1991;69(3):382–386. [PubMed] [Google Scholar]
11. Mimura T, Usui T, Mori M, Yamamoto H, Obata H, Yamagami S, Funatsu H, Noma H, Honda N, Amano S. Pinguecula and contact lenses. Eye (Lond). 2010 Nov;24(11):1685-91. doi: 10.1038/eye.2010.120. Epub 2010 Sep 10. PMID: 20829887.
12. Dundar H, Kocasarac C. Relationship Between Contact Lens and Pinguecula. Eye Contact Lens. 2019 Nov;45(6):390-393. doi: 10.1097/ICL.0000000000000586. PMID: 30801268.