Visual Outcomes and Endothelial Cell Loss in Dislocated Artisan Phakic IOL

1
Visual Outcomes and Endothelial Cell Loss in
Dislocated Artisan Phakic IOL

• Authors
• Jeewan S Titiyal, MD1
• Rashim Mannan, MD1
• Namrata Sharma, MD1
• Rasik B Vajpayee, MS, FRCS Ed1
• 1. Dr Rajendra Prasad Centre for Ophthalmic
  Sciences, All India Institute of Medical
  Sciences, New Delhi-110029, India
• Place of study Cornea and Refractive Surgery
  Services, Dr Rajendra Prasad Centre for
  Ophthalmic Sciences, All India Institute of
  Medical Sciences, New Delhi-110029, India.

2
ABSTRACT

• PURPOSE To study the visual outcomes and
  endothelial cell losses in dislocated Verisyse
  (Artisan) phakic lenses following successful
  re-enclavation.
• MATERIAL AND METHODS A retrospective analysis of
  9 eyes of 6 patients with dislocated Artisan
  phakic IOL, which underwent successful
  re-enclavation. A comparison between primary
  surgery and re-enclavation procedure regarding
  UCVA, BCVA and quantitative endothelial changes
  pre-operatively and at 1 week, 1month, 3 months
  and 6 months postoperatively was done using
  Friedman test and Wilcoxon Signed Rank Test.
• RESULTS Disenclavation was spontaneous in 6
  (66.6) and post traumatic in 3 cases (33.3).
  Mean UCVA and BCVA at 6 month following
  successful re-enclavation was comparable to the
  primary surgery (pgt0.05). The comparison of
  endothelial cell losses between the primary
  surgery and after re-enclavation, for the period
  pre-op to 1 week post-op was 2.13 vs 5.31
  (pgt0.05), 1 week to 1 month was 3.16 vs 3.55
  (pgt0.05), 1 month to 3 months was 0.78 vs 3.86
  (plt0.05) and 3 month to 6 months was 0.65 vs
  1.50 (pgt0.05).
• CONCLUSIONS The visual functions remain
  unaffected after re-enclavation although
  endothelial cell losses following successful
  re-enclavation occur over a longer period of time
  as compared to the primary surgery.

3
INTRODUCTION

• The safety and efficacy of Artisan phakic IOL
  (Verisyse IOL, AMO, Netherlands) implants have
  been reported recently in several studies.
• One of the problems which can occur in these
  phakic IOLs which requires repeat surgery
  includes the disenclavation of these phakic IOL
  implants.
• However, secondary surgical intervention in the
  form of re-enclavation can successfully overcome
  these problems.

PURPOSE

• We herein, report the results of our cases of
  PIOL implants in which disenclavation of one or
  both haptics occurred and wherein a successful
  re-enclavation was undertaken.

4
PATIENTS AND METHODS

• Prospective interventional case series
• Comprised of 9 eyes of 6 patients, implanted with
  Verisyse IOL during the period between May 2004
  to Jan 2006, who had to undergo re-enclavation of
  one or both the haptics following spontaneous or
  traumatic dislocation of the implant.
• A complete evaluation included
• History and mode of injury
• Duration of injury and / or symptoms
• UCVA and BCVA
• Slit lamp bio-microscopy examination
• Endothelial cell density
• All the cases had completed a minimum follow up
  of 6 months subsequent to re-enclavation surgery.
  
• The data was analyzed using Friedman's Two-way
  Analysis of Variance and Wilcoxon Signed Rank
  Test.

5
PATIENTS AND METHODS
Fig.1. Post traumatic dis-enclavation of Verisyse
phakic IOL
Fig.2. Same case as above, following successful
re-enclavation at post-op day1
6
RESULTS

• Nine eyes of 6 patients required re-enclavation,
  of which
• 4 were female
• 2 were males
• Two causes of disenclavation were seen,
• Traumatic The cause of disenclavation was trauma
  in 3 cases (33.3)
• Spontaneous Disenclavation was spontaneous in 6
  cases (66.6)
• Total disinsertion of the claw was seen in all
  the cases of traumatic disenclavations
• Whereas none of the cases of spontaneous
  disenclavation had total disinsertion.

Fig.3. Demographic and ocular parameters
7
RESULTS
Fig.4. Gain in UCVA and BCVA (Snellen Equivalent)
following successful re-enclavation, over a 6
month period.

• Following successful re-enclavation,
• The mean BCVA improved from 0.500.24 to
  0.730.24 Snellens equivalent at 6 months of
  follow up.
• The mean UCVA improved from 0.340.18 to
  0.470.25.
• Both the UCVA and the BCVA showed an initial
  increasing trend followed by a plateau beyond 1
  month of follow up.

8
RESULTS

• Following successful re-enclavation
• The mean endothelial cell density changed from
  2670 352 cells/mm2 to 2332 464 cells/mm2 over
  a period of 6 months (p0.00)
• A retrospective follow up analysis of the same
  eyes, over a period of 6 months, following
  primary phakic IOL implantation revealed that
• the mean endothelial cell density changed from an
  initial preoperative value of 2924 340
  cells/mm2 to 2728 312 cells/mm2 over a period
  of 6 months (p0.00).

Fig.5. Trends in endothelial cell counts
following primary surgery and following
successful re-enclavation, over a 6 month period.
9
DISCUSSION

• Study have also demonstrated depigmentation of
  the iris stroma at and near the site of
  enclavation ranging from 27.9 to 81 cases,
  which may lead to poor fixation of the phakic
  IOL. A four year multicenter study by Budo et al
  which evaluated the safety and efficacy of
  Artisan phakic IOLs also reported repositioning
  of decentered Artisan phakic IOLs in 5 cases.
• Similar iris tissue depigmentation was noted in
  all our cases which had spontaneous phakic IOL
  dislocations.
• All the cases of spontaneous subluxation were
  seen during the first year and a half of starting
  phakic IOL implantation at our centre. This could
  be attributed to the learning curve of the
  concerned surgeons. This can further be
  corroborated by the fact that none of the other
  cases since then have had a spontaneous
  subluxation.

10
DISCUSSION
Fig.6. comparison of trends of endothelial cell
losses following primary and re-enclavation
surgery

• The major percentage of cell loss in either
  primary or re-enclavation surgery were seen
  during first month of follow up (5.3 v/s 8.8).
• Surgical manipulations can be attributed to the
  steep losses seen during 1st month.

• Subsequently the endothelial cell losses were
  more following re-enclavation procedure (Fig. 6).
• This can be attributed to the underlying trauma
  to the endothelium because of subluxated phakic
  IOL. Also surgical re-enclavation of the phakic
  IOL, is technically more difficult due to
  concurrent corneal edema and iris atrophy causing
  difficulty in enclavation.
• Beyond 3 months, endothelial losses were similar
  for both procedures.
• This suggests that post re-enclavation the
  endothelium takes a longer time to revert back to
  its normal physiology than is the case with
  primary surgery.

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CONCLUSIONS

• Although our study does not comment upon the
  changing trends in endothelial cell density
  beyond 6 months of follow up.
• We propose that the largest reduction in the
  endothelial cell density following re-enclavation
  is seen in the first 3 months, subsequent to
  which the cell losses diminished.
• Also, we attribute the endothelial damage phakic
  IOL-endothelial touch which is partly due to
  subluxated phakic IOL and partly due to surgical
  maneuvers during the act of re-enclavation.
• However, these findings need to be substantiated
  by a longer case study as well as following up of
  the cases beyond 6 months of follow up.

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