Introduction

Assessment of functional vision, that is, the ability to move independently and perform daily activities, is crucial in patients with inherited retinal dystrophies, such as those associated with RPE65 gene mutations. The MLMT (Multi-Luminance Mobility Test) is a standardized method for evaluating functional vision under controlled lighting conditions.

Aim of study

Assessment of MLMT results in four patients with biallelic RPE65 mutations before and after gene therapy with voretigene neparvovec (Luxturna).

Material and methods

Four patients (two with Leber congenital amaurosis and two with retinitis pigmentosa) with confirmed biallelic RPE65 gene mutations were evaluated using the MLMT before, and at 30 and 90 days after subretinal gene therapy. The MLMT was conducted at various illumination levels (1-400 lux). Scoring took into account the time to complete the course and the number of errors. The criterion for passing the test was completing the course in ≤180 seconds with ≤ 3 errors.

Results

Before therapy, patients exhibited marked difficulties in completing the test, particularly under low light intensity conditions. Following therapy, all patients demonstrated either improvement or stabilization, evidenced by reduced completion times, fewer errors, and greater accuracy.

Conclusions

The MLMT is a valuable tool for assessing functional vision in patients with RPE65 gene mutations and for monitoring the effects of gene therapy, providing objective data on functional vision under conditions that closely resemble everyday life.