In a prospective clinical analysis at a tertiary eye center, this study investigated the clinical outcomes and objective decision-making criteria for intraocular lens exchange in patients with homogeneous intraocular lens calcification to provide evidence-based guidelines for discussing surgical benefits with patients and making treatment decisions.
“The incidence of intraocular lens (IOL) calcification strongly depends on the type of lens used at a particular time and in a geographic region,” the researchers wrote in their recent Eye and Vision article. “It is reported to vary from 5% to 30%, reaching up to 50% in specific cohorts. Even when assuming a low incidence of IOL calcification, with approximately 10 million cataract surgeries undertaken each year worldwide, one can expect that perhaps hundreds of thousands of patients are affected by this condition.”
The researchers included 53 eyes from 42 patients with homogeneous IOL calcification in the study, and the primary outcome measure was straylight reduction using C-Quant straylight meter. Secondary outcomes included corrected distance visual acuity (CDVA), contrast sensitivity, and patient-reported outcomes (Catquest-9SF questionnaire). A straylight value of 1.56 log(s) was identified as the threshold for recommending surgery, which correlated with subjective and functional improvements.
Compared to preoperative measurements (2.32 ± 0.34 log(s)), postoperative straylight measurements were 1.23 ± 0.33 log(s). This improvement was clinically and statistically significant. Further, straylight improved regardless of age, with significant benefits in visual comfort and glare sensitivity.
Preoperative CDVA was 0.16 ± 0.13 logMAR vs. 0.05 ± 0.10 logMAR (P < .05) post-op.
The investigators found marked contrast sensitivity improvement in all spatial frequencies, particularly under glare conditions.
IOL exchange led to notable reductions in halo size, glare intensity, and patient-reported visual disturbances. Patients who declined surgery showed no significant changes in straylight or visual symptoms.
The researchers concluded that straylight and contrast sensitivity measurements better capture visual impairment due to calcification compared to visual acuity alone. They recommended the 1.56 log(s) straylight measurement as a cut-off when deciding whether an IOL exchange surgery is the best decision for each patient because “patients had a 50% chance for improvement through surgery if the straylight value was above” this value.
A full list of author disclosures can be found in the published research