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Trifocal IOL Decisions
Careful candidate selection and thorough consultation facilitate good outcomes. Cheryl Guttman Krader reports
Trifocal IOLs can provide many patients with a full range of spectacle-free vision after cataract surgery, but this implant technology is not without limitations. Therefore, it is necessary to apply rigorous attention to candidate selection for achieving success and patient satisfaction, emphasises Burkhard Dick MD, PhD.
“Patients who will receive a trifocal IOL must have a strong desire for spectacle independence along with realistic expectations, and surgeons must respect the relative indications,” Dr Dick said.
Available trifocal IOLs include the Acriva Reviol Tri-ED, AcrySof® IQ PanOptix® (Alcon), AT LISA® Tri 839MP (Zeiss), FineVision POD F GF, and Versario® MF 3F (Bausch & Lomb). The clinical registration trials conducted for these lenses enrolled only patients with healthy eyes other than for the cataract, and there are limited studies involving eyes with more complex constellations. Therefore, decisions on trifocal IOL implantation in the latter eyes are more challenging.
The manufacturers’ product labelling lists the various contraindications, precautions, and warnings. Dr Dick reviewed his considerations.
He recommended against trifocal IOL implantation in eyes with a history of radial keratotomy where postoperative visual performance is likely to be poor. He also excludes patients with severe dry eye disease if the ocular surface cannot be optimised. The presence of corneal pathology—including epithelial and endothelial dystrophies, stromal scars, or opacification—is also a contraindication because of loss of contrast and increased risk of dysphotopsia.
A trifocal IOL may be considered for eyes that are glaucoma suspect or have early disease without obvious visual field loss, but not if the glaucoma is moderate to advanced because the implant will further reduce already decreased contrast sensitivity. In eyes with mild glaucoma, surgeons need to be aware that subtle central scotoma is more common, Dr Dick said.
“I recommend also doing a 10-2 visual field test (VF) in these cases to exclude early central fixation involvement because the Humphrey 24-2 VF can be completely normal. Moreover, simultaneously performed 10-2 and 24-2 VF demonstrate a superior topographic structure–function relationship when compared with them separately,” he said.
Trifocal IOLs may be considered for patients with a history of laser vision correction. Evaluation to identify good candidates should include topography and tomography. The surgeon should consider the type of ablation because it bears on selection of the optic design (aspheric, neutral, or spherical) and should check the functional optical zone size and centration.
Dr Dick said he excludes patients who had correction of more than 6.0 D of myopia or more than 4.0 D of hyperopia as well as those with elevated higher order aberrations (total >2.0 µm, coma >0.32 µm, trefoil >0.4 µm), although there are only weak data regarding the impact of preoperative corneal aberrometry on outcomes.
The preoperative workup should also include measurement of angle alpha and angle kappa. Dr Dick said caution and further evaluation are needed if either value is 0.3 to 0.5 microns while values >0.5 mm lead to patient exclusion. It is also important to perform dynamic pupillometry, as it confirms the photopic pupil is >2.5 mm in diameter.
He also recommended the ASCRS calculator for IOL power calculation, as well as ray tracing analysis. He suggested checking recent publications on IOL power calculations in eyes with previous corneal refractive surgery.1–2
This study was presented at the ESCRS Virtual Winter Meeting 2022.
1 Wang L, Koch DD. Ophthalmology. 2021; 128(11): e121-e131. 2 Panzanella SM, et al. Ophthalmology. 2021; 128(5): 781–792.
Burkhard Dick MD, PhD, FEBOS-CR is Director of the University Eye Hospital, Bochum, Germany. DICKBurkhard@aol.com
