Vision Degrading Myodesopsia Surgery May Induce Recurrent Floaters

Vision degrading myodesopsia (VDM) can be addressed with limited vitrectomy without surgical posterior vitreous detachment (PVD) induction — but this approach may leave some patients with recurrent floaters caused by new-onset PVD, according to a study published in Retina. For higher risk patients, surgeons may consider inducing surgical PVD at the primary operation to mitigate these recurrent floaters.

Researchers evaluated 286 eyes of 203 patients (mean age, 60.6±12.9 years; 118 men, 85 women) who were scheduled to undergo limited sutureless 25 G vitrectomy without intentional surgical PVD induction for VDM. Those with myopia and without complete PVD prior to vitrectomy (60 eyes of 42 patients; 33 men, 9 women) had a younger mean age (49.4±13.6 years) compared with those without myopia (39 eyes of 32 patients; 17 men, 15 women; mean age, 62.9±12.6 years; P <.001). Another 25 eyes had partial PVD preoperatively.

Following limited vitrectomy to manage vision degrading myodesopsia, 14 eyes developed recurrent central floaters. All 14 cases of recurrent floaters occurred in eyes without complete preoperative PVD. In all, 99 eyes in the study did not have complete PVD prior to surgery (an incidence rate of 14.1%). In the subgroup of eyes that underwent limited vitrectomy for vision degrading myodesopsia that had partial PVD prior to surgery (n=25), recurrent floaters occurred in 5 eyes (an incidence rate of 20.0%). 

Ultrasound imaging revealed that all recurrent floaters were associated with new-onset complete PVD.

“Partial PVD was a minor risk factor since one-fifth of this cohort experienced recurrent central floaters due to extension from partial to total PVD, but this group constituted 45.5% of all patients who chose to undergo repeat vitrectomy for recurrent central floaters,” according to the researchers. “Because all patients were diagnosed by vitreous ultrasonography to have new-onset complete PVD, this is the most likely mechanism for the recurrent floaters.”

Patients at the highest risk for recurrent floaters included those with younger age (<52 years, 71.4%), male sex (92.9%), myopia (≥-3 diopters, 85.7%), and phakic status (100%). Nearly half of the patients who opted to undergo a second surgery had preoperative partial PVD. These patients experienced a 45.6% improvement in contrast sensitivity (CS) after a second surgery (P =.033).

The researchers explain that limited vitrectomy may not be appropriate for patients with vision degrading myodesopsia who have not undergone complete PVD preoperatively. “To avoid recurrent central floaters (albeit low in frequency) due to new-onset PVD with renewed degradation of CS in at-risk patients and obviate the need for re-operation, surgeons may be advised to induce surgical PVD and use lower cutting rates when performing vitrectomy in VDM patients who are young, myopic, phakic males with a partial or no PVD,” according to the report.

Study limitations include its retrospective nature and the small sample size of patients with recurrent floaters.