9. Post-operative movement
Anterior movement of the lens implant may occur due to capsular bag fibrosis and contraction. Toric lenses may also rotate.
What do you do when there is a significant residual refraction? Rule number one: refractive error is not pathological.
While being blurry is annoying, it is not a medical problem. Patients should be reassured that the surgery went fine and the math involved is the only problem. Math problems can be solved.
Remeasure corneal curvature, autorefraction, manifest refraction, and aberrometry. Also dilate to examine the IOL.
I prefer to use other methods to evaluate the residual refraction to better understand what needs to be changed.
Look for misplaced optics, which may indicate a reversed implant or an implant in the sulcus rather than the capsular bag. Evaluate toric lenses for axis positioning and determine if the IOL has moved from its planned axis.
When the patient is mistakenly nearsighted, I routinely point out the advantages to having near vision before taking it away. The patient in the case mentioned earlier was -1.50-0.75 x 180 (20/20) OD, and -1.25-0.75 x 180 (20/20) OS.
He could read and use computers comfortably. I corrected him with contact lenses and showed him the effect of corrected distance vision on functioning at near.
His complaint when he returned a week later? “I can’t read.”
Surgery post-cataract surgery
Refractive correction after cataract surgery can be addressed using spectacles, contact lenses, refractive surgery, IOL exchange, or a piggyback IOL.
For patients who were not hoping for spectacle-free distance vision, wearing spectacles may not be a significant problem. problem. However, anisometropia may complicate spectacle correction. Wearing contact lenses works well if anterior segment health allows.
Refractive surgery post-cataract surgery can be successfully performed. PRK is preferred to avoid LASIK induced dry eye. PRK may be preferred to avoid LASIK-induced dry eye, so when discussing excimer surgery, do not speak of LASIK specifically. Leave options open for the surgeon.
It is best to wait three months after cataract surgery for refractive surgery to ensure the refraction is stable and corneal incisions have healed.
A lens may be removed and exchanged for another—hopefully more correct—IOL. IOL exchange cannot be performed after a YAG laser capsulotomy, so be sure you are happy with the IOL prior to performing the procedure.
This may be the better option when refractive errors—particularly anisometropia— are large, requiring significant change in refractive corneal power. This may also be preferred by surgeons who do not perform KRS.
Lens exchanges should occur quickly, prior to development of lens capsule fibrosis. Piggybacking involves the implantation of a second lens in the posterior chamber in front of the original IOL in the capsular bag. It is easier and safer than removing the lens.2
I always demonstrate the intended outcome using loose lenses or contact lenses prior to surgery to ensure the patient’s full understanding of the refractive target.
Reduce effect of residual refractive error
The best way for optometrists to reduce the effect of residual refractive error is to:
• Tell all patients you refer for cataract surgery that there is a risk they may need glasses full-time after surgery.
• Mention the increased risk before surgery in all patient with a history of any keratorefractive surgery.
• Mention the risk before surgery again because the first time, the patient probably did not hear you.
• If the patient is unhappy following cataract surgery, calmly assess a situation by remeasuring the numbers, and reassure the patient.
• Blame the math. Everyone hates math anyway.
1. Ladi JS. Prevention and correction of residual refractive errors after cataract surgery. J Clin Ophthalmol Res. 2017;5:45-50.
2. Amon M, Kahraman G. Enhancement of refractive results after intraocular lens implantation. European Ophthalmic Review. 2011,5(1):59-61.