Often yes. Treating dry eye and surface inflammation before glaucoma surgery may improve how well the eye heals, especially after filtering surgery. But if your pressure is dangerously high or your vision is falling fast, surgery does not wait.
Why the surface of your eye matters for glaucoma surgery
Most people think glaucoma surgery works only on the inside of the eye. The outside matters too.
Filtering surgery, such as trabeculectomy, creates a new drainage route under the conjunctiva. This is the thin, clear tissue covering the white of the eye. Healthy conjunctiva helps that route stay open.
Years of glaucoma drops can leave this tissue red, dry and inflamed. Many patients on long-term drops already have ocular surface disease without knowing it. This can result in poor surgical results.
How glaucoma drops affect the ocular surface
Several things happen together:
- Preservatives in many drops irritate the surface of the eye. Sometimes, the drug itself causes an allergic reaction
- Over time, tear quality worsens, and the eyes feel gritty or burn
- The conjunctiva becomes red and more inflamed
- The oil glands in the lids can clog, which makes dry eye worse (Meibomian Gland Disease)
Read more about glaucoma drops and dry eye and preservative-free glaucoma drops in India.
Why does ocular surface disease affect glaucoma surgery?
An inflamed conjunctiva tends to scar more. Scarring can close the new drainage route, and the pressure then rises again.
Studies link long-term drop use and conjunctival inflammation with poorer results after filtering surgery. Most of this evidence is observational. That means the link is real, but I cannot promise that treating the surface will change your result.
The surface also matters after surgery. You will use drops often for weeks, and a sore, dry eye copes with them poorly.
What does treatment before surgery involve?
I look at the lids, tear film and conjunctiva before I plan surgery. Treatment depends on what I find. It may include:
- Switching to preservative-free drops, or fewer drops
- Lubricating drops that match your tear problem
- Treating blocked oil glands and lid inflammation
- Short courses of anti-inflammatory drops, when needed. If I need to use low dose steroids for this, its always under strict supervision for any increase in eye pressure
- Stopping drops that cause an allergic reaction
NOTE: Before trabeculectomy, I usually start a low dose steroid eyedrop like flouromethalone to help ease the inflammation, along with preservative free lubricating eyedrops. If needed, I put the patient on oral acetazolamide to control the pressures while the conjunctiva heals. Many glaucoma surgeons do the same- the surgical results of a friable, inflamed conjunctiva are usually poorer.
With MIGS, I am as vigilant about my patient’s comfort, but I know that the IOP related surgical outcome is less dependent on conjunctival health.
Read about brimonidine allergy and red eyes if redness is your main problem.
Does this delay surgery?
Sometimes, by a few days. I weigh that delay against your pressure and your risk of losing vision.
Surgery should not wait when:
- Your eye pressure is dangerously high
- Your field loss is progressing quickly
- You are close to losing central vision
In these cases, I operate and treat the surface at the same time.
Does this apply to every type of glaucoma surgery?
No. Filtering surgery and tube surgery depend most on healthy conjunctiva. Some minimally invasive procedures leave the conjunctiva untouched, so the surface matters less for the operation itself.
It still matters for comfort and healing. Read about MIGS and glaucoma surgery.
Please also read about Why We Treat Dry Eye Before Cataract Surgery
Preoperative Evaluation
| What I see | Likely cause | When to worry |
|---|---|---|
| Red, bloodshot eyes on glaucoma drops | Inflammation from drops or preservatives | If redness is constant or one eye is worse |
| Gritty, burning eyes | Dry eye or damaged tear film | If vision blurs between blinks |
| Crusting along the lids | Blepharitis or blocked oil glands | If lids are swollen or sore |
| Itchy eyes with sticky discharge | Allergy to a drop | If lids swell |
| Scarred or thin conjunctiva | Years of drops or earlier surgery | Raises the risk of surgical scarring |
What doctors often miss
- Surface checks come late, or never. Many surgical plans focus only on pressure and the nerve.
- Every drop is treated as harmless. Preservatives and allergy add up over years.
- Redness is assumed to be normal. A bloodshot eye on drops is a warning sign.
- Dry eye is blamed on age. It is often treatable, and a short treatment course can help before surgery.
What this means for you
Healthy surface tissue gives glaucoma surgery a better chance of working. It does not guarantee success, and it should never delay urgent surgery.
If your eyes are red, sore or gritty on glaucoma drops, tell me before you book surgery. We can often improve the surface while we plan.
When to See a Doctor
See a Doctor Urgently
- Severe eye pain, with or without nausea
- Sudden fall in vision
- A red eye with light sensitivity and falling vision
- Rapidly worsening redness or discharge after eye surgery
See a Doctor
- Red, gritty or burning eyes on glaucoma drops
- Eyes that sting every time you use a drop
- Swollen or crusted eyelids
- Surgery advised, and you have never had your tear film checked
- Dry eye that your current treatment does not control
Frequently Asked Questions
Can dry eye affect the result of glaucoma surgery?
It may. Surface inflammation is linked to more scarring after filtering surgery. Treating it before surgery may help, but results vary.
How long should I treat my eyes before glaucoma surgery?
It depends on your pressure and how severe the surface problem is. Often it is a few days, to a few weeks. Your doctor will not delay surgery if your vision is at risk.
Should I stop my glaucoma drops before surgery?
No. Do not stop drops without advice. Your doctor may switch you to a gentler drop and keep your pressure controlled.
Does preservative-free medicine help before surgery?
It may help the surface calm down. Availability and cost vary in India. Ask your doctor what suits your eyes.
Do I need this if I am having a MIGS procedure?
The surface matters less for the operation itself. It still helps comfort and healing.
Book a Consultation with Dr Bhartiya
Planning glaucoma surgery and your eyes feel sore or red? At my clinic in Gurgaon, any glaucoma work-up includes a thorough evaluation of the ocular surface, and your quality of life. Come to see me, or send me your reports, and I will check your ocular surface before we plan surgery.
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This page is part of the Glaucoma hub. Read about our full approach to glaucoma surgery. Please also read Second Opinion Framework for Dry Eye, How to manage side effects of glaucoma drops, and Glaucoma progressing despite eye drops. Here’s another heartening patient story: Avoid Glaucoma Surgery.
About the Author
This article was written by Dr Shibal Bhartiya, fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator, Clinical Director at Marengo Asia Hospitals, Gurugram, known for ethical, patient-centred glaucoma care and independent glaucoma second opinions. She is also the Program Director for Community Outreach & Wellness; and for the Marengo Asia International Institute of Neuro and Spine.
Dr Bhartiya has published peer-reviewed research on glaucoma management, examining how treatment decisions should balance medical evidence, patient preferences, and long-term vision outcomes. She is also a committed patient advocate and mainstream medical columnist, translating complex ophthalmic evidence into actionable public health insights across leading national platforms including NDTV and OnlyMyHealth
Dr Bhartiya is the Editor-in-Chief of Clinical and Experimental Vision and Eye Research and Executive Editor of the Journal of Current Glaucoma Practice (Pubmed Indexed, official journal of the International Society of Glaucoma Surgery). Her 200+ publications, including 90+ PubMed-indexed publications and 28 edited textbooks span glaucoma biology, surgical outcomes, health equity, and emerging diagnostics.
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Last Reviewed: November 2026