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IMMUNOLOGY:
Phacoanaphylactic endophthalmitis is a rare autoimmune
inflammatory reaction to lens protein and is most
often a consequence of lens injury (or surgery) in the elderly.
In approximately 20% of cases, there is no evidence of a penetrating
wound (1). An immune complex reaction (type
III hypersensitivity response) arises secondary to an altered
tolerance to lens protein, with or without prior injury (2).
HISTOPATHOLOGY:
Histopathological diagnosis is based on evidence of a zonal
granulomatous inflammatory response around lens material.
CLINICAL DIAGNOSIS:
Clinical diagnosis is frequently inaccurate, as the clinical presentation
is variable (1). However, correct diagnosis is paramount as lensectomy
is curative. We studied a case of spontaneous phacoanaphylactic
endophthalmitis confirmed by cytopathology (3).
THIS STUDY: As
in our case, anterior capsule rupture occasionally occurs spontaneously.
These cases are associated most frequently with a hypermature
cataract (4). If inflammation ensues, the diagnosis
of phacoanaphylactic endophthalmitis is
established by the presence of a zonal granulomatous response
(polymorphonuclear leukocytes surrounding lens material, in turn,
surrounded by a granulomatous zone—giant cells and epithelioid
cells—with an outer, nonspecific mononuclear cell infiltrate)
(2).
OTHER STUDIES:
Green and coworkers previously reported cytopathologic findings
of phacoanaphylactic endophthalmitis in 8 patients (3,5). Specimens
were obtained by vitrectomy and, in some cases, by using anterior
chamber aspirates, and were prepared by a millipore filter and
modified Papanicolaou staining technique. Findings included lens
capsule, epithelioid cells, lymphocytes, neutrophils, and multinucleated
giant cells. In one case, lens material with a zonal granulomatous
inflammatory reaction was described. Our patient’s specimen,
obtained via anterior chamber fine needle aspiration biopsy, harbored
these findings.
In most cases, anterior chamber exposure to lens protein does
not lead to phacoanaphylactic endophthalmitis. Otherwise, phacoanaphylactic
endophthalmitis would develop in many patients with residual cortical
material after cataract extraction. Altered immune tolerance to
lens protein has been shown only in select individuals, and the
resultant immune complex reaction is phlogogenic (2).
REFERENCES
1. Thatch AB, Marak GE Jr, McLean IW, Green WR. Phacoanaphylactic
endophthalmitis: a clinicopathologic review. Int Ophthalmol 1991;
15:271-9.
2. Marak GE Jr. Phacoanaphylactic endophthalmitis. Surv Ophthalmol
1992; 36:325-39.
3. Engel HM, Green WR, Michels RG, Rice TA, Erozan YS. Diagnostic
vitrectomy. Retina 1981; 1:121-49.
4. Chishti M, Henkind P. Spontaneous rupture of the anterior
lens capsule. Am J Ophthalmol 1970; 69:264-70.
5. Green WR. Diagnostic cytopathology of ocular fluid specimens.
Ophthalmology 1984; 91:726-49.
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