Posterior Chamber Phakic IOL Corrects Pathologic, Nonpathologic Myopia Equally

Posterior chamber phakic intraocular lens (pIOL) implantation can treat pathologic and nonpathologic myopia equally well, according to a study published in BMC Ophthalmology. The implantable device significantly improved uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) for both groups at 6 months postoperative.

Between July 2017 and October 2021, researchers retrospectively reviewed records of 192 eyes from 100 consecutive patients undergoing implantation with a posterior chamber phakic IOL at a single center in China. This clinical case series study included 171 eyes from 86 patients with nonpathologic myopia (group 1; average age, 25.5 years; age range, 22-30 years; 76 women, 10 men) and 21 eyes from 14 patients with pathologic myopia (group 2; average age, 33 years; age range 29-43 years; 8 women, 6 men). 

The preoperative spherical equivalent (SE) was -9.31 diopters (D) in group 1 and -17.50 D in group 2. At 6 months after posterior chamber phakic IOL  implantation, the SE were 0.00 D in group 1 and -0.50 D in group 2, and the refraction changes were statistically significant (P ≤.05). 

At 6 months after the operation, 76.92% in group 1 and 80.41% in group 2 were within ±0.50 D of the target and 92.31% in group 1 and 95.88% in group 2 were within ±1.00 D. 

All eyes experienced unchanged BCVA or gained 1 or more lines in both groups. The mean BCVA in both groups improved by 1 line 6 months after surgery. 

The efficacy index was 0.95 in group 1 and 0.88 in group 2 and the safety index was 1.20 in group 1 and 1.33 in group 2, indicating that the safety index between the 2 groups were significantly different. During the 6-month follow-up, no cataract, pigment dispersion glaucoma, pupillary block, or other vision-threatening complications occurred in either group. 

The study supports the view that the posterior chamber phakic IOL performs equally well in correction of pathologic myopia as it does in nonpathologic myopia, according to the researchers.

“Both the postoperative UDVA and BCVA in group 1 were significantly better than in group 2, possibly because patients in group 1 had lower rates of myopia than those in group 2,” the researchers explain.

Study limitations include its retrospective design, the small study sample of patients with pathological myopia, the overrepresentation of women in the non-pathological myopia group, and the duration of follow-up (6 months) may have been insufficient.