pseudoexfoliation syndrome ( pes ) is characterized by the production and accumulation of fibrillar extracellular material within the ocular tissue .
the presence of pes is of paramount clinical importance in patients undergoing cataract surgery , because it is associated with a high rate of complications such as zonular dialysis , rupture of the posterior lens capsule , vitreous loss and dislocation of the intraocular lens ( iol ) .
pes has also been identified as a main factor predisposing to secondary open - angle glaucoma .
spontaneous dislocation of a posterior chamber iol ( pc / iol ) represents an unusual , severe complication , which mostly occurs in the late postoperative period and requires exchange surgery of the pc / iol or pc / iol repositioning with scleral fixation [ 2 , 3 , 4 ] . in all cases reported in the literature ,
an in - the - bag pc / iol was subluxed posterior into the vitreous cavity . here , we report on a patient with pes who developed partial acute angle - closure glaucoma ( acg ) with a marked myopic shift due to anterior dislocation of the pc / iol almost 16 months after an uneventful phacoemulsification . to the best of our knowledge ,
this is the first case of late - onset anterior pc / iol dislocation with partial acg and a marked myopic shift , which resulted in a permanent alteration of the postoperative target refraction .
a 70-year - old male underwent an uneventful clear - cornea phacoemulsification with pc / iol implantation in the right eye ( od ) in january 2006 .
preoperative routine examination disclosed a bilateral corticonuclear cataract as well as features of pes od ( fig .
there was no other medical history , and the patient did not receive any medication .
, we implanted a capsular tension ring ( ctr ) in order to stabilize the posterior capsule and prevent zonular - capsular complications .
a pmma ctr ( type 14 , 10-mm closed diameter ; morcher gmbh , stuttgart , germany ) was implanted , which , according to our personal experience , represents a simple and reliable solution for cases with moderate risk .
finally , a foldable pc / iol ( hydrophilic acryl ) was inserted in the bag , without any complication occurring during the surgical procedure .
after one week , the patient 's best corrected visual acuity ( bcva ) was 1.0 ( refraction 0.25/0.5/110 ) .
slit - lamp examination demonstrated a marked shallowing of the anterior chamber , without any other visible pathological findings ( fig .
intraocular pressure ( iop ) was 29 mm hg od and 11 mm hg os .
evaluation of refraction unravelled a significant myopic shift od ; bcva was 1.0 with 3.75/0.5/110. the refractive status os was 0.25/0.75/115 and bcva was 1.0 .
scheimpflug examination documented a prominent axial anterior dislocation of the pc / iol od , without fluid accumulation between the posterior capsule and the pc / iol ( fig .
the pc / iol was sitting in the capsular bag os , and the anterior chamber depth was 5.21 mm ( fig .
iop elevation resisted to topical therapy with -2 receptors agonists ( brimonidine eye drops ) and , therefore , one week later nd : yag iridotomy was performed .
iop was successfully regulated od after nd : yag iridotomy ( direct postoperative iop : 14 mm hg ) .
nevertheless , the shallowing of the anterior chamber did not significantly improve , and the anterior dislocation of the pc / iol remained unaltered ( refraction 2.75/0.75/110 , bcva 1.0 ) .
although the myopic shift od was not eliminated , the patient was satisfied with the monovision , which was achieved unintentionally and , therefore , we did not proceed to an exchange surgery of the pc / iol .
pes is associated with a high incidence of pc / iol dislocation in cataract surgery , whether it is an in - the - bag pc / iol or an out - of - the - bag pc / iol .
this unusual complication may occur with any type of pc / iol on average 8.5 years after its implantation .
it is important to note that all cases reported up to date in the literature manifested a posterior pc / iol dislocation in the vitreous cavity .
our patient presented with a myopic shift and acg due to delayed anterior pc / iol dislocation od .
slit - lamp examination did not reveal an anterior capsular opacification of elements of phimosis which could explain the anterior dislocation of the pc / iol - ctr complex . during a thorough preoperative explanatory discussion
, the patient was informed about the complication risk due to the underlying pes , and he strongly insisted that we should implement any necessary precautionary measures during the operation to minimize this risk .
therefore , we decided to implant a ctr during the operation in order to stabilize the posterior capsule and prevent zonular - capsular complications , although we did not observe phacodonesis or difficulties in pupil dilation preoperatively .
von der lippe et al .   first postulated that zonular weakness in some patients with pes may lead to anterior subluxation of the lens with consecutive ciliary block acg .
use of a ctr during the cataract surgery did not prevent this complication , since ctr implantation in pes - associated zonular weakening does not guarantee long - term zonular stability . in our patient , nd : yag iridotomy resulted in a satisfactory iop regulation , but the emmetropic refractive status was not restored .
our patient was satisfied with the monovision ( od refraction 2.75/0.50/110 , od bcva 1.0 ; os refraction 0.25/0.75/115 , os bcva 1.0 ) and , therefore , we did not proceed to pc / iol exchange or pc / iol repositioning . to the best of our knowledge ,
this is the first report of late - onset anterior pc / iol dislocation in pes , generating a permanent myopic shift .
ophthalmologists should be aware of this potential complication , which may occur in patients with pes within a considerable period of time after cataract surgery , and these patients should be warned accordingly .
 here , we report on a patient with pseudoexfoliation syndrome who developed acute angle - closure glaucoma with a marked myopic shift due to anterior dislocation of the posterior chamber intraocular lens almost 16 months after an uneventful phacoemulsification . 
 examination with a scheimpflug camera was extremely useful in confirming the diagnosis . 
 this is the fist case of late - onset angle - closure glaucoma with a significant myopic shift due to anterior dislocation of the posterior chamber intraocular lens , which resulted in a permanent alteration of the postoperative target refraction . 
Introduction
Case Report
Discussion
Disclosure Statement