What are the special considerations if cataracts occur after myopic laser surgery? Is there any difference in treatment? (Feature Interview with Dr. Lung-Kun Yeh)
Video Source: Ophthalmology Community
Q1: What are the special considerations if cataracts occur after myopic laser surgery?
After myopic laser surgery, the refractive curvature of the cornea changes, so the calculation of the cataract surgery IOL needs to be corrected. Most IOL measurement formulas are based on corneal curvature and eye length; if your corneal curvature has changed, the IOL power must be corrected. Therefore, if cataracts develop after myopic laser surgery, it is important to inform your surgeon that you have had myopic laser surgery prior to cataract surgery so that the surgeon can adjust the IOL calculation formula to accurately estimate the required IOL power. If you do not tell your surgeon beforehand, the IOL power may vary by several hundred degrees. In the past, there have been cases where the surgeon’s IOL calculation was not corrected after photorefractive keratectomy (PRK) because the incisions were not easily visible on the cornea after recovery.
Q2: Should I tell my doctor about my previous myopic laser surgery before surgery?
If you have previously had Radial Keratotomy (RK), the actual calculation will not make much difference. However, in the case of photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK), the difference in the calculation formula is more significant, so we choose a special calibration formula that gives more accurate results. There are now more advanced methods to detect corneal curvature more accurately, but it is still recommended that the patient and doctor discuss whether they want to leave a little to compensate for presbyopia or whether they want to be able to remove their glasses after the surgery (see far and near without glasses), which is very important for the patient and doctor to consider when choosing the lens.
Q3: Does the difference in formula lead to a different treatment?
There is not much difference in surgical treatment, but cataract surgery has to be done at the right time. If you wait until the lens is too ripe (too mature) and even minimally invasive surgery may not be possible, then you may have to use traditional cataract surgery with large incisions, which can have a greater impact on recovery. As for the use of femtosecond laser-assisted cataract surgery, patients should discuss this with their cataract surgeon.
Q4: Does LASIK or SMILE require complicated formulas?
Yes, myopic surgery actually changes the refractive error of the cornea. The change in refraction changes the values needed to calculate the formula, so we must make corrections when entering them into the formula. It is very important to communicate with your surgeon before surgery so that he/she can optimize your vision after surgery. For patients who need cataract surgery after myopic laser surgery, it is important to talk to your surgeon beforehand so that the exact corneal curvature can be calculated and then entered into the formula for a more perfect vision correction.