Severe Ptosis Changes Ocular Biometric Parameters for Cataract Surgery

Severe ptosis (>4 mm) significantly affects corneal curvature values and intraocular lens (IOL) power calculations for patients who require cataract surgery, according to research published in the Journal of Cataract and Refractive Surgery. For patients set to undergo ptosis repair following cataract removal, surgeons may need to alter lens power choice, the study shows.

Patients with involutional ptosis were divided into 3 groups based on droopy eyelid severity, determined by margin reflex distance, with more than 4 mm indicating a severe case, 3 to 4 mm indicating a moderate case , and 1 to 2 mm being mild. All patients underwent anterior levator resection (ALR), and the investigators collected preoperative and 3-month postoperative biometry measurements.

A total of 57 patients participated in the study, 19 in the larger than 4 mm group (mean age, 61.42 years), 22 in the 3 to 4 mm group (mean age, 63.90 years), and 16 in the 1 t0 2 mm group (mean age, 65.37 years). 

The researchers found that the mean K₁, K₂, and K_m values significantly decreased 3 months postoperatively in the more than 4mm group (P <.001 for all) but were not significantly different from baseline in the 3 to 4 mm group and 1-2 mm group. They also found that the mean corneal astigmatism magnitude decreased 3 months postoperatively in the more than 4 mm-group (P <.01) but was not significantly different from baseline in the 3 to 4 mm group and 1 to 2 mm group. 

The team also demonstrated that the mean recommended IOL powers targeting emmetropia (calculated using 5 different formulas) increased postoperatively in the more than 4 mm group (0.47 D for SRK/T; 0.52 D for Hoffer Q; 0.55 D for Haigis; 0.50 D for Barrett Universal II; 0.55 D for Holladay 2; P <.001 for all) but were not significantly different pre- and postoperatively in the 3 to 4 mm group and 1 to 2 mm group. 

“Clinicians should be aware of the potential change in ocular biometric parameters in severe ptosis patients who have undergone ALR. Changes in the strategy or timing may be needed for these patients when cataract or corneal refractive surgery is planned,” according to the researchers.

Limitations of the study included that lack of comparison of the results to those of patients with congenital ptosis and the absence of a patient group with frontal suspension and Müller’s muscle conjunctival resection.