Endoscopic transnasal prelacrimal recess approach via the orbital floor to the infraorbital region: an anatomical study.

PURPOSE: The aim of this study is to describe the maximum exposure of the infraorbital region via the orbital floor using the transnasal prelacrimal recess approach (PLRA), and to provide an anatomical basis for treating lesions in the infraorbital region.

METHODS

Ten freshly injected frozen heads were dissected using the PLRA. The orbital floor was removed along the border of the medial infraorbital quadrangle, and the periorbita was opened to expose the infraorbital region. The areas of the medial infraorbital quadrangles were measured and analyzed. The PLRA was applied separately on the left and right sides of each cadaver head, resulting in a total of 20 prelacrimal recess approaches.

RESULTS

The PLRA enabled visualization of the optic nerve and the central retinal artery through the orbital floor. By integrating both medial and lateral approaches in relation to the inferior rectus muscle, all crucial anatomical structures within the infraorbital region could be clearly identified. The area of the medial infraorbital quadrangle was 420.65 ± 24.03 mm2.

CONCLUSION

The PLRA provides access through the orbital floor to the maximum boundary of the infraorbital region, including the lateral orbital wall at the outermost level, the superior rectus muscle at the topmost level, and the medial orbital wall at the innermost level.