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1 Tennent Institute of Ophthalmology, Gartnavel General Hospital, Glasgow, UK
2 Department of Pathology, Western Infirmary, Glasgow, UK
Accepted for publication 2 December 2002
Keywords: epithelial downgrowth; phacoemulsification; buphthalmos
Epithelial downgrowth is a rare complication which can occur following anterior segment surgery and penetrating ocular injury. A prevalence as high as 16–29% among eyes enucleated after cataract surgery has been reported in the older literature, but advancements in the microsurgical techniques have decreased that rate to less than 0.2%.1 To our knowledge only two cases of epithelial downgrowth following clear corneal phacoemulsification have been reported.2,3 We present the clinical and histopathological features, and the successful surgical management, of a patient with extensive intraocular involvement of epithelial downgrowth with following clear corneal phacoemulsification.
Case report
A 26 year old man was followed up for bilateral congenital glaucoma. He had undergone several bilateral trabeculectomies in the past. Preoperatively his intraocular pressures (IOP) were well controlled with no medication. He underwent phacoemulsification with implantation of a poly(methylmethacrylate) (PMMA) lens through a 5 mm superior clear corneal wound in the right eye. The corneal wound was closed with Nylon sutures, as the eye wall was thin secondary to buphthalmos and the temporal end of the wound was irregular extending to the limbus. At the end of the surgery the wound appeared secured with a deep anterior chamber. Two weeks postoperatively he presented with wound leak from the corneal section. A conjunctival hood was fashioned over the corneal wound in an attempt to prevent wound leak. Four weeks later he developed an epithelial downgrowth in the form of a retrocorneal membrane with involvement of the iris from the 7 o’clock to 2 o’clock position (fig l, top). He underwent a corneo-sclero-iridocyclectomy with removal of the IOL and posterior capsule combined with anterior vitrectomy. No adjunctive cryotherapy was used. A horseshoe-shaped corneoscleral graft was sutured in place. Histopathological examination confirmed extensive downgrowth of non-keratinised stratified squamous epithelium involving the cornea, the angle, anterior and posterior surface of the iris, the ciliary body, and extending on to the posterior capsule (fig 1, bottom and fig 2, top). At 17 months follow up he had a vision of 6/12 with aphakic correction and there was no evidence of recurrence of the downgrowth (fig 2, bottom).
Figure 1 Top: Clinical photograph showing epithelial downgrowth over the anterior surface of the iris (yellow arrows). Note the Haab’s striae on the cornea (blue arrow). Inset: Showing epithelial downgrowth as a retrocorneal membrane (yellow arrow). Bottom: Histological section showing crowding of epithelium in the corneal phaco wound (grey arrow). There is downgrowth of stratified squamous epithelium over the corneal endothelium (blue arrow), anterior surface of the iris (green arrow), and the posterior iris pigment epithelium (orange arrow) (haematoxylin and eosin, x250).
Figure 2 Top: Histology showing epithelial downgrowth over the anterior surface of the ciliary body (black arrows) (haematoxylin and eosin, x250). Bottom: Retroillumination showing a secure graft-host junction. Note the Haab’s striae in the cornea.
Comment
Epithelial downgrowth is characterised by progressive advancement of an epithelial membrane onto the intraocular surfaces and it can lead to intractable and painful glaucoma. It can occur in three forms: (1) "pearl tumours" of the iris, (2) epithelial cyst, (3) growth of epithelium as a sheet on to the anterior chamber structures. This last form has been shown to have the worst prognosis.4 Although there is no single predisposing factor, wound fistula, damage to the corneal endothelium, and corneal stromal vascularisation can have a role in the pathogenesis of the epithelial invasion.1 Various methods have been tried in the treatment of epithelial downgrowth.1 It has been shown that patients treated surgically underwent fewer enucleations than patients managed conservatively. However, surgical management of epithelial downgrowth is difficult, particularly when the anterior chamber contains sheets of epithelium. Knauf et al2 reported surgical success following surgical excision of a localised cystic downgrowth. Extensive disease involvement is associated with a poor outcome.4 We feel that early detection and surgical intervention can result in improved outcome even in cases where the downgrowth has extensive intraocular involvement as demonstrated in this case. Experimental evidence suggests that the presence of endothelium inhibits epithelial downgrowth through direct intercellular interactions.5 There are previous reports documenting decreased endothelial cell density in eyes with congenital glaucoma.6,7 It is possible that the decreased endothelial cell count combined with persistent wound leak would have contributed to the extensive downgrowth of the epithelium in our patient. We hope this case report highlights this rare complication of small incision cataract surgery.
References
Weiner MJ, Trentacoste J, Pon SM, et al. Epithelial downgrowth: a 30-year clinicopathological review. Br J Ophthalmol 1989;73:6–11.
Knauf HP, Rowsey JJ, Margo CE. Cystic epithelial downgrowth following clear-corneal cataract extraction. Arch Ophthalmol 1997;115:668–9.
Lee BL, Gaton DD, Weinreb RN. Epithelial downgrowth following phacoemulsification through a clear cornea. Arch Ophthalmol 1999;117:283.
Stark WJ, Michels RG, Maumenee AE, et al. Surgical management of epithelial ingrowth. Am J Ophthalmol 1978;85:772–80.
Cameron JD, Flaxman BA, Yanoff M. In vitro studies of corneal wound healing: epithelial—endothelial interactions. Invest Ophthalmol Vis Sci 1974;13:575–9.
Wenzel M, Krippendorff U, Hunold W, et al. Corneal endothelial damage in congenital and juvenile glaucoma. Klin Monatsbl Augenheilkd 1989;195:344–8.
Mastropasqua L, Carpineto P, Ciancaglini M, et al. In vivo confocal microscopy in primary congenital glaucoma with megalocornea. J Glaucoma 2002;11:83–9.