Endophthalmitis possible until sutureless phaco incisions heal

Patients tended to achieve better visual results when a vitrectomy was performed no later than 3 days after onset of symptoms.

ByMichael Piechocki

MUNICH – Patients can inadvertently open sutureless phaco incisions up to 2 weeks following surgery, allowing for the occurrence of bacterial infection and endophthalmitis, according to a study presented here.

Rubbing and touching sutureless cataract surgery incisions can open the incisions, compromising the intraocular environment and allowing fluid to leak. This leakage can give bacteria a path to enter the eye, according to Cosme I.N. Naval, MD, an ophthalmologist in San Juan, Metro Manila, Philippines.

“Germs are powerful swimmers and dive into the conjunctival pool of tears. Without proper antibiotic treatment, these invade the incision and move into the chamber,” Dr. Naval told Ocular Surgery News in an interview.

“The type and healing of an incision can definitely lead to late endophthalmitis. Leaking incision, poor coaptation, burned incision, delayed closure – all these invite endophthalmitis,” he said.

Dr. Naval and Analyn T. Suntay, MD, evaluated the cause of six cases of endophthalmitis that developed in six patients who had undergone uncomplicated phacoemulsification with foldable IOL implantation. Dr. Naval presented the results of the study at the German Ophthalmic Surgeons annual meeting.

In all cases, the pathway of infection was associated with patient-induced opening of the surgical incision. Additionally, the infecting organism was identical to those isolated from other patient-specific infections, according to the study.

Sterile surgery

The study included six cases of late onset endophthalmitis treated by Dr. Naval between October 1998 and February 2004. All patients had undergone uncomplicated phacoemulsification followed by placement of an AcrySof (Alcon) foldable IOL.

Cosme I.N. Naval [photo]
Cosme I.N. Naval

Betadine (povidone-iodine, Alcon) and Tegaderm (3M) drapes were used in all cases to prepare the eye for surgery, and only disposable drapes, needles, cassettes and tubing were used for the procedure, Dr. Naval said.

All patients received intraoperative intravenous sulbactam and ampicillin, and topical ciprofloxacin was also applied postoperatively, he noted.

Cataract surgeries were completed using an incision no larger than 3.75 mm, which allowed for the foldable IOL to be inserted. Postoperatively, the incisions were sealed by pressure-testing the anterior chamber in all cases, he said.

However, healing of the wound and sealing of the wound are not the same, he continued. Because no sutures were placed, there remained the possibility of the wound opening and contamination being introduced during the postop period until the incision was well-healed. This could occur from unconscious compression of the eye while asleep or from rubbing, Dr. Naval said.

“A cataract surgery incision may be sealed, meaning no aqueous leaks from the wound in an eye’s normal state. But it may not be healed because when the eye is touched or compressed the incision can gape and thereby leak; the chamber is lost and thereby bacteria can enter during its reformation,” he said.

“The incision is really healed if, no matter how we compress the eye, no leakage is produced,” Dr. Naval said.

The time required for an incision to heal depends upon how much surgical trauma and heat are generated during phacoemulsification and may take up to 14 days, he said.

Initial darkening of vision

Among the six cases, endophthalmitis developed within 2 weeks after surgery; one case each was diagnosed at postoperative day 1, 5, 7, 10, 12 and 14, according to the study.

In all cases, patients developed an acute darkening of vision caused by a clouding of the vitreous. This was confirmed by indirect ophthalmoscopy or biomicroscopy and differentiated from retinal detachment or vitreous hemorrhage, he said. “It would be an error just to simply watch the anterior chamber.”

“I emphasize dimness because the most remarkable symptom of these patients is that they complain vision gets very dark,” he said. “This signifies that the vitreous is the primary site of infection in these cases. The reason is that during phacoemulsification fluid is forced under pressure and thereby opens the pathways into the vitreous. It would be a gross misjudgment to miss the early warning of endophthalmitis by waiting for changes in the anterior chamber alone.”

As soon as dimness of vision with vitreous cloudiness was seen, anterior and posterior taps were performed, according to the study. These samples were stained and cultured, and culture sensitivity testing was performed to identify the infecting organism. If the gram staining demonstrated bacteria, early vitrectomies were performed immediately without waiting for the results of the culture sensitivities.

“Waiting for bacterial identification and antibiotic sensitivity would unduly delay the vitrectomy leading to poor prognosis. Subsequently, as bacterial identities and sensitivities were determined, the antibiotic regimens were modified,” Dr. Naval added.

Sources of infection

A different strain of bacteria was isolated from each patient, the study said (See Table).

Haemophilus influenzae was isolated from one patient with an upper respiratory tract infection. Escherichia coli was isolated from one patient with a nasolacrimal tube implant in the fellow eye. Staphylococcus aureus and Staphylococcus epidermidis were isolated from one patient each who had diabetes but no other comorbid conditions; Streptococcus and Klebsiella were isolated from one patient each with both diabetes and chronic obstructive pulmonary disease (COPD), according to the study.

The researchers speculated that the source of the infection might have been from the influenza infection in one patient’s nasolacrimal duct; from the patients’ own skin in the two Staphylococcus cases; from the fellow eye of the one patient with E. coli infection; and were endogenous in origin in the two patients with Streptococcus and Klebsiella infections, which probably stemmed from the respiratory tree in the COPD cases.

“The same type of bacteria were cultured from their suspected sources of origin as those which infected their eyes, confirming the above pathways of infection proposed by the authors,” Dr. Naval said.

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For Your Information:
Cosme I.N. Naval, MD, can be reached at 17 AB Strata Suites, 300 P. Guevarra, San Juan, Metro Manila, Philippines 1500; 63-2-744-0865; fax: 63-2-721-6785; e-mail: cinn@i-manila.com.ph.
Michael Piechocki is an OSN Staff Writer who covers all aspects of ophthalmology, specializing in oculoplastics. He focuses geographically on Europe and the Asia-Pacific region.