This eye appears to have true exfoliation of the anterior lens capsule. The membrane was identified before surgery, and when the intraocular anesthetic agent was injected the anterior leaflet of the delaminated anterior capsule of the lens became evident.1 This uncommon disorder occurs most often in persons such as glassblowers or bakers who have been occupationally exposed to heat in the facial area on a prolonged and repeated basis.2 A split occurs in the anterior capsule with the formation of a delaminated area with or without a visible free edge. Although the pathogenesis is uncertain, enzymatically mediated proteolysis or thermal radiation damage to the subjacent abnormal lens epithelium are proposed mechanisms.3,4 A possible forme fruste variety may become apparent during cataract surgery, with the appearance of a double-ring sign to the anterior capsule observed during capsulorhexis.5
In this patient, phacoemulsification can be safely performed if the condition is recognized before the capsulorhexis is initiated.6,7 Vital dye staining of the capsular complex with trypan blue, performed under a layer of OVD, would help identify and differentiate the exfoliated detached edge of the anterior leaflet from the intact posterior lamella of the anterior capsule. Both layers are thinner than the normal anterior capsule, so care must be exercised to avoid tearing the capsule during the capsulorhexis or during other parts of the procedure. The anterior capsule leaflet can be removed in a curvilinear manner to create a smaller anterior capsulorhexis. Then, a larger anterior capsulorhexis incorporating both anterior capsule lamellae would be performed. This could be done in the usual manner using a capsulorhexis forceps while grasping both the anterior and posterior lamella of the anterior capsule. Although both lamellae are thinner than normal, the anterior capsulorhexis can be performed without radial tears. After standard phacoemulsification of the nucleus and aspiration of the lens cortex, an IOL can be safely maneuvered into the capsular bag without incident. The posterior capsule has not been reported to be thin or otherwise problematic. It is probably wise to be extra cautious during any part of the procedure that comes in contact with the edge of the thinned and delaminated capsulorhexis.
Often, true exfoliation is present in the fellow eye but may not be apparent on slitlamp biomicroscopy. Anterior segment OCT or high-frequency ultrasound will sometimes show a separation between 2 anterior capsule lamellae and allow the surgeon to be prepared to appropriately manage the capsule layers during surgery.
Compared with the much more common condition of PEX, in true exfoliation there is actual delamination of the anterior lens capsule but no deposition of fibrillo-granular material, no glaucoma, and no weakness of the zonules, as is found in PEX. Of course, these 2 entities may coincidentally occur together, compounding the potential difficulties of the surgery.
1. Karp CL, Fazio JR, Culbertson WW, Green WR. True exfoliation of the lens capsule. Arch Ophthalmol. 1999;117:1078-1080.
2. Elschnig A., 1922. Abhlösung der Zonulalamelle bei Glasblasern [Detachment of the zonular lamellae in glassblowers.], Klin Monatsbl Augenheilkd, 69, 732-734.
3. Meades K, Versace P. True exfoliation of the lens capsule. Aust NZ J Ophthalmol. 1992;20:347-348.
4. Callahan A, Kilen BA. Thermal detachment of the anterior lamella of the anterior lens capsule; a clinical and histopathologic study. AMA Arch Ophthalmol. 1958;59:73-80.
5. Abe T, Hirata H, Hayasaki S. Double-ring and double-layer sign of the anterior lens capsule during cataract surgery. Jpn J Ophthalmol. 2001;45:657-658.
6. Cooke CA, Lum DJ, Wheeldon CE, Teoh H, McGhee CN. Surgical approach, histopathology, and pathogenesis in cataract associated with true lens exfoliation. J Cataract Refract Surg. 2007;33:735-738.
7. Kulkarni AR, Al-Ibrahim J, Haider S, Elsherbiny S, Scott R. Phacoemulsification in true exfoliation of the lens capsule: a case series. Eye. 2007;21:835-837.