ODs’ diagnostic role crucial to good patient outcome in endophthalmitis management

Issue: March 1996

ISELIN, N.J.—By carefully monitoring post-cataract surgery patients, optometrists can play a key role in lessening the severity of endophthalmitis when it occurs. In addition, because the rise of less virulent strains of bacteria has caused an increase in delayed onset of infections, ODs need to follow patients for longer periods of time.

Christopher J. Quinn, OD, from Omni Eye Services, a referral center practice here, said, "One of the most important facets of endophthalmitis management is making an early diagnosis, because then the result after treatment tends to be much, much better."

Advanced endophthalmitis displays classic symptoms: acute onset of severe pain, dramatic decrease in vision and increase in intraocular inflammation. However, its early stages are much more difficult to detect. Quinn said optometrists should focus on patients who complain about any deep, penetrating pain or decrease in vision.

Delayed onset

Patients who complain about these symptoms should be seen in the office as soon as possible, no matter how long after surgery. In the past, there was a 3- to 5-day window after surgery when endophthalmitis was high on the list of potential complications. "Today, there are less virulent types of bacterial infections that occur," Quinn said, "so almost any time after surgery the doctor must be aware of the possibility of endophthalmitis."

Once the patient is in the office, Quinn said optometrists can look for clinical characteristics. One is any increase in intraocular inflammation. Normally after surgery, he said, the amount of inflammation inside the eye steadily decreases. If at any point inflammation increases, then the OD must "have a very high index of suspicion for early endophthalmitis," he said.

ODs should also look for a hypopyon. "If a patient comes in and has a hypopyon, the doctor must consider endophthalmitis until it’s proven otherwise," Quinn said.

To aid diagnosis, optometrists can perform standard office tests such as best corrected acuity check and a slit-lamp examination of the anterior segment and chamber.

If the evaluation indicates endophthalmitis, Quinn said it is best to refer the patient to the surgeon. "The definitive way to diagnose the disease is to culture fluid from the anterior chamber by using an anterior chamber tap or a core vitrectomy," he said. "Some of the vitreous should be cultured to see if there is an infectious organism that can be isolated and treated."

Treat with caution

Also, post-cataract patients occasionally develop sterile endophthalmitis, possibly as a reaction to preservatives in intraocular fluids. These noninfectious inflammations demand treatment with steroids. "I wouldn’t want to be the person trying to differentiate sterile from infectious endophthalmitis," Quinn said. "If you’re wrong and you treat an infectious endophthalmitis with steroids, it’s going to explode and you’ll have a very serious situation."

If endophthalmitis is confirmed as noninfectious, Quinn said optometrists have a role in treating it. "Then it’s a matter of keeping the patients on steroids, modulating the steroid treatment to reduce the inflammation and eventually getting the patient off the steroid."

Treatment with specific antibiotic

Quinn said infectious endophthalmitis management involves getting high concentration of a specific antibiotic into the eye, based on the results of the culture. Topical and intravitreal drugs are most effective. Recent studies indicate no significant benefit to using intravenous antibiotics. Vitrectomy is indicated in patients who have light-perception vision.

Subconjunctival antibiotics can be considered, although he said, "It’s not a great option because it can be painful and because you probably don’t achieve as high an intraocular level as you do with the topical."

Patients can also ultimately undergo a vitrectomy, where the vitreous is removed and antibiotics are injected into the eye.

Cases of delayed-onset injections are becoming more common, Quinn said. "Today, a lot of these endophthalmitises are low-grade, and they can smolder and be held in check for weeks or even months after surgery. As a result, they are difficult to pick up in the postop routine."

Two main bacteria strains can cause delayed onset of infection: S. epidermidis and Propionibacterium. Proprioni are anaerobic, Quinn said, and sometimes these infections "will not be clinically apparent for months. Even a long time after surgery a patient could suddenly get endophthalmitis related to the surgery."

He added that fungal infections, which are less common, can also have a delayed onset.