Corneal ulcer treatment depends on what caused the infection, but nearly all cases require aggressive use of medicated eye drops, sometimes as often as every hour around the clock. Mild ulcers can heal in one to two weeks with proper treatment, while severe cases may take several months. The goal is to eliminate the infection, control inflammation, and preserve as much vision as possible.
A corneal ulcer is an open sore on the cornea, the clear front surface of your eye. Most are caused by bacterial infections, but viruses, fungi, and parasites can also be responsible. Because the wrong treatment can make certain types worse, identifying the cause is the first and most important step.
How the Cause Is Identified
Your eye doctor will examine the ulcer with a slit lamp, a specialized microscope that lets them see the cornea in detail. They’ll look at the shape, size, and depth of the ulcer, along with any surrounding inflammation. In many cases, especially for larger or deeper ulcers, they’ll gently scrape a tiny sample from the cornea and send it to a lab to identify the specific organism. This matters because bacterial, viral, fungal, and parasitic ulcers each require completely different medications.
While waiting for lab results, treatment usually starts immediately with broad-spectrum antibiotic drops to cover the most common bacterial causes. If the lab results point to a different type of infection, your doctor will adjust the treatment plan.
Treatment for Bacterial Ulcers
Bacterial infections are the most common cause of corneal ulcers, especially in contact lens wearers. Treatment centers on antibiotic eye drops, typically from the fluoroquinolone family. Newer-generation fluoroquinolones have become preferred as first-line options because they cover a broader range of bacteria.
The initial dosing schedule is intense. You’ll typically apply drops every hour, around the clock, including overnight. This means setting alarms to wake up and put in drops throughout the night for the first day or two. As the infection responds, your doctor will gradually reduce the frequency. This tapering process is important because prolonged use of certain concentrated antibiotic drops can actually slow healing by irritating the corneal surface.
For more severe infections, your doctor may prescribe fortified antibiotics. These are specially compounded drops with higher concentrations than standard commercial products, sometimes combining two different antibiotics to attack the infection from multiple angles.
The Role of Steroid Drops
Inflammation from the infection itself can cause scarring that permanently reduces vision. To limit this damage, steroid eye drops are sometimes added to the treatment regimen. The timing of when steroids are introduced matters significantly. Research has shown that adding steroid drops within two to three days of starting antibiotics resulted in roughly one line better visual acuity at three months compared to patients who received no steroids. Interestingly, when steroids were added four or more days after starting antibiotics, that benefit disappeared. Steroids are never used alone for bacterial ulcers because they suppress the immune response and can worsen the underlying infection.
Treatment for Viral Ulcers
The herpes simplex virus is the most common viral cause of corneal ulcers. These ulcers often have a distinctive branching pattern called a dendritic ulcer that your doctor can recognize during examination. Treatment involves antiviral medication rather than antibiotics.
For surface-level herpes ulcers, topical antiviral ointment applied five times daily for one to two weeks is the standard approach. An oral antiviral taken twice daily for seven days is an alternative when the ointment causes irritation or isn’t tolerated well. Patients with weakened immune systems are more likely to need the oral form.
Deeper herpes infections that involve the inner layers of the cornea are more complex. These require a combination of oral antiviral medication and steroid eye drops to control the immune-driven inflammation. The steroid taper for these deeper infections is slow, often stretching beyond ten weeks, and the antiviral must continue the entire time steroids are being used to prevent the virus from reactivating.
Treatment for Fungal Ulcers
Fungal corneal ulcers are less common but tend to be more stubborn and harder to treat. They often occur after an eye injury involving plant material, soil, or organic matter. Two antifungal eye drops are the primary options, and both are applied topically to the cornea.
The treatment schedule mirrors the aggressive approach used for bacterial ulcers: drops every hour while awake for the first week, then every two hours while awake for at least the next two weeks. Unlike bacterial ulcers, which often show improvement within days, fungal infections respond slowly. Treatment commonly lasts weeks to months, and progress can feel frustratingly gradual. Your doctor will monitor the ulcer closely during this period because fungal infections are more likely to worsen or fail to respond, potentially requiring surgical intervention.
Treatment for Parasitic Ulcers
Acanthamoeba keratitis is a rare but serious parasitic infection strongly linked to contact lens use, particularly wearing lenses while swimming or showering. It’s one of the most painful and difficult types to treat because the organism forms a protective cyst stage that resists most medications.
Treatment typically involves a combination of two types of antiseptic eye drops used together. According to the CDC, the standard regimen pairs a biguanide antiseptic with a diamidine antiseptic. What sets this infection apart is the duration of treatment: therapy often lasts six to twelve months or longer. The extended timeline is necessary because the drops must continue until the dormant cyst forms of the parasite are fully eliminated, not just the active forms.
When Surgery Becomes Necessary
Most corneal ulcers heal with medication alone, but some cases require surgical intervention. A corneal transplant, where the damaged section of cornea is replaced with donor tissue, may be needed when the infection doesn’t respond to medication, when the ulcer has perforated (created a hole through) the cornea, or when severe scarring after healing blocks vision beyond what glasses or contact lenses can correct.
Fungal and parasitic ulcers are more likely to reach this point than bacterial ones. In cases where the cornea is at risk of perforating but a full transplant isn’t yet necessary, your doctor may use other techniques like tissue grafts to stabilize the eye and buy time for the infection to be controlled.
What Recovery Looks and Feels Like
The first signs that treatment is working include reduced pain, less redness, and decreasing sensitivity to light. Your doctor will measure the ulcer at follow-up visits, and it should get progressively smaller as the surface layer of the cornea regenerates. Excessive tearing should also decrease as healing progresses.
Mild ulcers may heal fully within one to two weeks. More severe cases can take several months. Even after the infection clears and the surface heals, the cornea continues to remodel and strengthen over time. Vision improvement often lags behind the visible healing. You may notice your sight gradually sharpening over weeks to months as remaining inflammation subsides and the corneal tissue stabilizes. Some ulcers leave a scar that permanently affects vision, particularly those that were deep or centrally located.
Managing Drops and Daily Care
Treating a corneal ulcer at home means juggling multiple eye drop medications on a demanding schedule. If you’re using more than one type of drop, wait three to five minutes between each one. This gives each medication time to absorb rather than being washed out by the next drop. Keeping a written log of what you administered and when can help you stay on track, especially during the overnight doses.
Avoid rubbing your eye, even when it’s uncomfortable. Don’t wear contact lenses until the infection has fully cleared and your eye doctor gives explicit approval to resume use. There is no standard minimum waiting period that applies to everyone. Your doctor will evaluate the cornea’s condition before making that call. If your ulcer was related to contact lens wear, expect a conversation about switching lens types, improving cleaning habits, or adjusting your wearing schedule to reduce the risk of recurrence.
Keep all follow-up appointments, even if your eye feels better. Corneal ulcers can appear to improve on the surface while deeper infection persists, and premature tapering of medication is one of the most common reasons for relapse or worsening.