We have previously featured an article about doing cataract surgery in these highly myopic eyes, so we will focus on the surgical technique in this article and video.
This patient has an axial length of more than 30 mm and has more than -15 diopters of myopia at the pre-operative consultation. The IOL calculations using the Ladas Super Formula Artificial Intelligence method on IOLcalc.com indicate that using a +6.0 D IOL will leave about -2 D of myopia as a post-op refraction. For this patient who is an accountant, having excellent near and computer vision from a -2 refraction (50 cm optimal focal point) is highly desirable.
Another consideration is that the +6.0 D SN60WF IOL still has the same lens geometry and same A-constant as the rest of the IOL range. If we use a different IOL model, be aware that very low dioptric powers (positive and negative) may have markedly different A-constants.
In creating the capsulorhexis, be aware that these axial myopes also tend to have larger anterior segments and making a precise capsulorhexis of 5 mm in diameter is important to hold the 6 mm IOL optic in position. We cannot simply go by the pupil size for estimation of capsulorhexis size because the dilation may be 10 mm and the white-to-white can be 13 mm. In this case we use the marks on the capsulorhexis forceps to make a highly accurate capsulorhexis.
For nucleus disassembly. using a supra-capsular flip-and-chop technique is helpful to get the cataract out of the capsular bag. We must avoid posterior capsule rupture because that will put this highly myopic eye at risk for retinal break and detachment. In this case, we even had the patient see a retinal specialist before cataract surgery to ensure that there were no pre-existing weak areas that would benefit from laser retinopexy prophylaxis.
Click below for the narrated video about this case: