Phacoantigenic Reaction Masquerading as Postoperative Endophthalmitis in a Silicone Oil-filled Eye.

A 72-year-old phakic male with immature cataract underwent vitrectomy with silicone oil injection in his left eye for rhegmatogenous retinal detachment. The surgery was uneventful except for lens touch during vitrectomy. Two weeks postoperatively, he presented with circumcorneal congestion, hypopyon, and absent fundal glow suggestive of postoperative endophthalmitis. The patient was managed conservatively as he refused further intervention. Five weeks later, ocular inflammation subsided following posterior dislocation of the cataractous lens, thus revealing the error in our initial diagnosis. Following surgical intervention, the inflammation gradually settled. However, the eye progressed to the prephthisical stage. Phacoantigenic reaction following lens touch during vitreoretinal surgery is very rare. Hence, surgeons should maintain a high index of suspicion in similar case, and prompt intervention is warranted to prevent further complications.

Introduction

A phacoantigenic reaction to sequestered lens protein usually occurs following capsular rupture or dehiscence, secondary to trauma or surgery. Straub[1] was the first to suggest that liberated lens proteins could incite a reaction within the eye. Verhoeff and Lemoine[2] further refined this concept and coined the term “endophthalmitis phacoanaphylactica,” to describe severe inflammation in the eye following release of lens matter into the anterior chamber. However, this term was a misnomer because, initially, the pathology was not clearly understood as it was not a true anaphylactic reaction. Clinically unsuspected cases have been reported following trauma and extracapsular cataract extraction with residual lens matter.[34]

We report a case of a 72-year-old male who presented with a phacoantigenic reaction masquerading as endophthalmitis, following vitreoretinal surgery with silicone oil injection.

Case Report

A 72-year-old male, diagnosed with hypertension 4 years before presentation, experienced sudden onset blurring of vision in the left eye for 4 days duration. Best-corrected visual acuity was 6/18, N6 in his right eye and light perception with inaccurate projection in the left eye. Clinical examination indicated an immature senile cataract in both eyes with relative afferent pupillary defect in his left eye. Fundus examination of the right eye was within normal limits while the left eye revealed the presence of subtotal rhegmatogenous retinal detachment secondary to posterior vitreous detachment induced horseshoe tear. He underwent vitrectomy, 360° encirclage, endolaser with silicone oil injection in the left eye. Intraoperatively, except for a localized area of lens touch during vitrectomy, the surgery was uneventful. On the first postoperative day, the eye was quiet with a good view of the fundus, an attached retina and intraocular silicone oil. Two weeks later, the patient presented with sudden onset of pain, redness, watering, and blurring in his left eye. Vision was light perception.

Ocular examination indicated circumcorneal and conjunctival congestion, fresh medium-sized keratic precipitates inferiorly, a 2 mm white hypopyon and localized lens opacity [Figure 1a]. Intraocular pressure was normal. Fundus examination revealed loss of red reflex. We suspected postoperative endophthalmitis, and an anterior chamber tap was planned. However, the patient refused further intervention including the tap. The patient was advised of the nature of the condition, chances of worsening, and poor visual prognosis in the setting of infection, and he was managed conservatively. Repeat blood tests ruled out the presence of systemic infection and diabetes. Intensive fortified topical antibiotics (cefazolin (50 mg/ml) hourly and fortified tobramycin (14 mg/ml) hourly) and topical steroids (prednisolone 1% eye drops hourly) were initiated along with atropine eye drops three times and systemic moxifloxacin 400 mg once a day. The patient was followed up daily. One week later, the inflammation decreased significantly with a reduction in the hypopyon; however, the cataract showed significant progression with a visible white plaque on the posterior lens surface [Figure 1b]. The red reflex of the fundus was now visible. The patient continued using topical antibiotics and topical steroids and attended daily follow-up visits. At the third week of follow up, an aggressive inflammatory reaction was present and an increase in the hypopyon along with significant progression in the cataract was noted [Figure 1c]. The patient was counseled again on the need for repeat intervention such as cataract removal, silicone oil removal, and intravitreal antibiotic injections. The patient consented to intervention after a few days.

Figure 1

Slit-lamp photograph of the left eye on: (a) The second postoperative week revealing conjunctival and circumcorneal congestion with fibrin over the anterior lens capsule and a hypopyon of 2 mm. (b) The third postoperative week revealing significant reduction in the inflammation with a reduction in the hypopyon, but the cataract showed significant progression with a visible white plaque on the posterior lens surface. (c) The fourth postoperative week revealing worsening of condition indicated by an increase in the hypopyon and the cataract with a white plaque posteriorly. (d) The fifth postoperative week revealing reduced congestion, a quiet anterior chamber and aphakia with an intact anterior capsule

At evaluation preoperatively, there was a notable improvement in the symptoms. Clinical examination revealed a quiet anterior chamber with complete disappearance of the hypopyon. Most notable was the presence of aphakia instead of a cataractous lens. The anterior capsule was intact while a large defect was noted in the posterior capsule corresponding to the area of intraoperative lens touch [Figure 1d]. Fundus evaluation revealed a posteriorly dislocated cataractous lens [Figure 2]. The retina was attached with the silicone oil in situ. He underwent silicone oil removal along with removal of a posteriorly dislocated cataractous lens. The intraocular lens was implanted over the anterior capsule. The postoperative regimen included topical Moxifloxacin four times a day, homatropine eye drops two times a day for 3 weeks, and prednisolone acetate 1% eye drops every 2 h initially with a gradual taper over 2 months. The patient was prescribed a course or oral steroids (tab prednisolone 60 mg daily tapered every 1 week to 10 mg). Postoperatively, the inflammation settled with topical and oral steroids. Unfortunately, although the inflammation subsided and the retina was attached, the intraocular pressure gradually reduced over a few months despite the absence of wound leak and the eye became prephthisical.

Figure 2

Intraoperative view of a posteriorly dislocated lens during lens removal surgery

Discussion

To the best of our knowledge, a phacoantigenic reaction following vitrectomy in phakic eyes has not been previously reported. Lens touch is a commonly reported complication during vitrectomy.[5] However, not all cases of intraoperative lens touch causing a breach in the posterior capsule manifest with this type of phacoantigenic reaction. Thus, the inciting factor of the inflammatory reaction in our patient remains unknown.

Early diagnosis of the phacoantigenic reaction and differentiating it from infectious endophthalmitis or a sterile postoperative inflammation is very important as management strategies differ. Zimmer-Galler et al.[6] have reported a case of endophthalmitis in an oil-filled eye in an AIDS patient. They[6] reported a partially absorbed cataract initially; however, during surgical intervention, a dropped nucleus (similar to our case) was observed. Although they[6] presumed lens-induced uveitis initially, microbial cultures on two separate occasions were positive for the same organism confirming the presence of coexisting endophthalmitis. Zimmer-Galler et al.[6] reported persistent inflammation despite the surgical intervention, and the condition was resolved with aggressive management of endophthalmitis.

Acute onset of symptoms in the early postoperative period in our patient led to the initial misdiagnosis of acute bacterial endophthalmitis. Our patient refused further intervention, preventing the initiation of an aggressive management for infectious endophthalmitis and the subsequent course of the condition revealed the error in our initial diagnosis.

Fine-needle aspiration and Western blot have been reported to aid diagnosis of lens-induced uveitis.[78] However, these are not routinely practiced.[78] Hence, a high index of clinical suspicion is necessary, especially when a plaque-like material is visible at the posterior lens surface, as a phacoantigenic reaction is usually initiated at the site of exposed lens matter.[9] Due to the patient refusal, we were unable to perform confirmatory tests and the diagnosis was based solely on the clinical profile. However, the resolution of hypopyon and a white eye following lens dislocation ruled out the possibility of infective endophthalmitis. Thach et al.[9] have also reported missed initial diagnoses in several cases due to clinical similarities with other conditions. They[9] observed that in these cases, intraocular pressure ranged from 0 mmHg up to 70 mmHg. They[9] attributed the low pressures to the chronic inflammation with consequent phthisis. Prompt removal of lens matter may restore visual acuity;[3] however, chronic inflammation may predispose these eyes to other complications such as retinal detachment, optic atrophy, and phthisis.[4]

Thus, phacoantigenic reaction following lens touch during vitrectomy can mimic postoperative endophthalmitis, and a high index of clinical suspicion with early surgical intervention is necessary to salvage the eye.

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Conflicts of interest

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