There are various classifications of IOLs, each with its own advantages and disadvantages. For diabetic patients, there are two main points to note: 1. The size of the optical diameter of the lens The optical diameters of IOLs commonly used in clinical practice are 5.5mm, 6.0mm and 6.5mm. The advantages of small diameters are: small surgical incision, small corneal astigmatism, and light crystal weight, which may reduce post-surgical complications. However, at present, the difference in weight of foldable IOLs with different optical diameters is not significant, and the requirements for incision are not very different. Basically, these are no longer the main issues to be considered for surgery, while there are two complications with small diameters that cannot be ignored. One is that the optical portion is too small to cover the entire pupillary area, and some light reaches the retina directly through the area between the IOL edge and the pupil, forming a blurred object image and double vision. Secondly, stronger light rays are scattered at the edge of the optical portion of the IOL, which can lead to a flashing sensation. Both ghosting and flashing sensation can cause great discomfort to the patient, and this complication is even more pronounced if the lens is small and deviates.
The most important thing in choosing an IOL for diabetic patients is the presence or absence of fundus pathology, and even if not, the implantation of an IOL with a larger optical diameter should be considered for the future. The main reason is that diabetic retinopathy requires laser treatment, the crystal diameter is too small to perform retinal photocoagulation in the equatorial and peripheral parts, the retinopathy deteriorates, and the patient still does not have good visual function. If it can be determined that diabetic retinopathy will not be allowed in the future, it is a different story.
2. Another issue that needs to be considered is the material of the crystal. The hard crystal is mainly PMMA material (polymethylmethacrylate), which is the most commonly used and longest used IOL material with no intraocular degeneration, good biocompatibility, no biodegradation, physical properties of light weight, not easily broken, and stable performance. The disadvantage is the relatively poor resistance to laser damage during posterior laser capsulotomy. Soft folding IOL materials mainly include silicone (silicone), hydrogel (PHEMA), acrylate (acrysof), etc. Diabetic patients should decide which material of folded lens to use according to their economic status and actual condition, and the choice of crystal should generally be preferable in terms of easy implantation during surgery, light postoperative reaction, and less likely to form posterior barriers.