Intraoperative problems with acrylic intraocular lens (IOL) insertion and/or their postoperative implications have rarely been reported.1–3 Improper unfolding of a single-piece IOL (Acrysof, Alcon Laboratories, Inc.) caused by 1 of the haptics sticking to the optic is often known to occur.4 We report a case of a twisted leading haptic of a single-piece Acrysof IQ IOL causing progressive postoperative IOL tilt and subsequent lenticular astigmatism.
A 52-year-old diabetic man presented with posterior subcapsular cataract in both eyes. His corrected distance visual acuity was 20/120 and 20/80 in the right eye and left eye, respectively. The patient had “uneventful” clear corneal phacoemulsification with implantation of a single-piece hydrophobic acrylic intraocular lens (Acrysof IQ, SN60WF). Retrospectively, there had been slight decentration of the IOL at the end of the surgery that seemed to right itself when a dialer was used. On the first postoperative day, the uncorrected distance visual acuity (UDVA) was 20/200 in the right eye with astigmatism of −5.75 × 75. Slight IOL tilt was noted with the nasal edge of the optic, being visible at the level of the caspsulorhexis edge (Figure 1, A). There was an air bubble in the well-formed anterior chamber that prevented visualization of the upper haptic. There was no evidence of a posterior capsule defect or obvious fluid or ophthalmic viscosurgical device (OVD) in the bag; hence, a decision to observe was made.
The patient returned for a review 1 day later. Ocular examination showed that the IOL optic was now at nearly 90 degrees to the capsule with the optic edge visible in the pupillary plane (Figure 1, B). A twist of the upper haptic (at the 1 o’clock position) was easily visible at the optic–haptic junction (Figure 1, C). This twist had caused the upper haptic to face downward instead of upward, as it should have. This twist had not been visible until then. The patient was taken to the operating room for IOL repositioning under aseptic conditions. Slight lifting and dialing of the IOL caused the twisted haptic to untwist and open into the right position. The IOL then comfortably slipped back into the bag (Figure 1, D). The patient had a UDVA of 20/20 in the right eye the day after the untwisting procedure.
To our knowledge, this is the first report of a haptic of a single-piece Acrysof IOL twisting during insertion. There are plenty of instances of improper unfolding of an IOL after insertion into the bag. Most of these are caused by inadequate OVD in the cartridge or rarely by the incorrect loading of the IOL.4 These occurrences are, however, instantly recognizable on the operating table because the IOL fails to unfold or sit properly in the bag even after apparent unfolding. In our case, the IOL unfolded with ease and even appeared to slip into position in the bag. This caused complete oversight of the twisting of the leading haptic. The memory of the haptic then caused it to untwist, albeit slowly. This untwisting process caused the slight IOL tilt and the significant astigmatism on the first postoperative day. The twist itself was not, however, visible at that time. A day later, this untwisting process had progressed enough to nudge the IOL out of the capsular bag, pushing the edge of the IOL into the pupillary plane.
We believe that the twist may have occurred due to inadequate OVD in the cartridge while the IOL was being loaded. Postoperative astigmatism of this magnitude must set alarm bells ringing, and it may be prudent to look for a twist in the haptic in cases in which IOL tilting or unexplained postoperative astigmatism is observed.
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3. Shah U. Probable edge defect in Acrysof single-piece intraocular lens. Indian J Ophthalmol. 54, 2006, p. 277-278, Available at: http://www.ijo.in/article.asp?issn=0301-4738;year=2006;volume=54;issue=4;spage=277;epage=278;aulast=Shah
. Accessed January 30, 2015.
4. Van Vreeswijk H. Safe and easy way to release sticking haptic of a single-piece AcrySof intraocular lens. J Cataract Refract Surg