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I read with interest the case report of Ashraff et al where a
posterior chamber phakic intraocular lens (PCPIOL) was used in a
pseudophakic eye with axial myopia and pseudoexfoliation for the
management of anisometropia. I would like to highlight a potential
problem in such eyes: dislocation of PCPIOL into the vitreous cavity.
PCPIOLs are inserted blindly behind the iris and, depen...
PCPIOLs are inserted blindly behind the iris and, depending on the
design, allow their haptics to rest at the structures of the posterior
chamber or float in it. Ultrasound biomicroscopy (UBM) identified haptic-
zonules contact and lens rotation for the Implantable Contact Lens (ICL)
and the Phakic Refractive Lens (PRL), although these PCPIOLs are intended
to fixate at the ciliary sulcus and float in the posterior chamber
respectively. Because of this potential haptic-zonules contact and lens
rotation of PCPIOLs the entire zonular apparatus should be intact and
Pseudoexfoliation is characterised by progressive zonular disruption
and axial myopia by zonular weakness and both conditions may lead to
zonular defects. Although phakodonesis and iridodonesis may point towards
zonular insufficiency, those signs may be absent in a number of eyes with
occult zonular defects as shown in UBM studies. Such zonular defects may
result in spontaneous dislocation of the PCPIOL into the vitreous cavity.
Two cases have been described already where PCPIOLs dislocated into the
vitreous cavity through such defects. Kaya et al. reported a case of
dislocation of a silicone PCPIOL into the vitreous cavity following mild
head injury three weeks postoperatively in a highly myopic eye (–19 DS).
Another case of dislocation of a myopic PRL into the vitreous cavity has
been reported by the European Clinical Trial with PRL group [Philipson B.
PRL (phakic posterior chamber IOL)-the 12 month results of the European
clinical trial. Presented at the XXI Congress of the ESCRS-Munich 2003].
I have recently reported a case of spontaneous dislocation of a PRL into
the vitreous cavity in a young healthy female with high myopia two months
postoperatively (spherical equivalent –19.5 D). (H Eleftheriadis, S
Amoros, R Bilbao, MA Teijeiro. “Spontaneous dislocation of a Phakic
Refractive Lens into the vitreous cavity”. Submitted for publication to
the J Cataract Refract Surg December 2003).
The reported cases stress the importance of health and integrity of
zonular apparatus in the long-term stability of PCPIOLs. Since
pseudoexfoliation is a progressive disease that may lead to progressive
zonular disruption and spontaneous IOL-bag dislocation into the vitreous
cavity even many years after cataract surgery, I think that PCPIOLs
should not be used in pseudophakic eyes with pseudoexfoliation.
1. Ashraff NN, Kumar BV, Das A et al. Correction of pseudophakic
anisometropia in a patient with pseudoexfoliation using an implantable
contact lens. Br J Ophthalmol. 2004;88:309.
2. Trindade F, Pereira F, Cronemberger S. Ultrasound biomicroscopic
imaging of posterior chamber phakic intraocular lens. J Refract Surg.
3. Garcia-Feijoo J, Hernandez-Matamoros JL, Mendez-Hernandez C et al. Ultrasound biomicroscopy of silicone posterior chamber phakic
intraocular lens for myopia. J Cataract Refract Surg. 2003;29:1932-1939.
4. McWhae JA, Crichton AC, Rinke M. Ultrasound biomicroscopy for the
assessment of zonules after ocular trauma. Ophthalmology. 2003;110:1340-
5. Kaya V, Kevser MA, Yilmaz OF. Phakic posterior chamber plate
intraocular lenses for high myopia. J Refract Surg. 1999;15:580-585.
6. Jehan FS, Mamalis N, Crandall AS. Spontaneous late dislocation of
intraocular lens within the capsular bag in pseudoexfoliation patients.