Three-dimensional changes of scleral show after surgical treatment of endocrine orbitopathy

Surgery in endocrine orbitopathy should address exophthalmos and adjunct stigmata such as increased lid aperture and scleral show. Secondary to decompression, rehabilitative surgical treatment such as blepharoplasty is routinely used to achieve this goal. Until now, however, there has been no investigation to measure the effect of decompression surgery on scleral show and lid aperture 3-dimensionally.

Ocular surface area (OSA) and lid aperture of 34 patients (67 orbits) were measured pre and post decompression surgery in a retrospective investigation using 3-dimensional (3D) stereophotogrammetry. The mean follow-up after decompression was 6 ± 4 months.

Mean OSA ranged between 3.1 ± 1.5 cm² (pre orbital decompression) and 2.5 ± 0.6 cm² (post orbital decompression). Orbital decompression caused a statistically significant reduction of the surface area of about 19.4% (p < 0.001). Lid apertures showed average values between 12.7 ± 3.3 mm (pre orbital decompression) and 11.3 ± 2.2 mm (post orbital decompression). Thus orbital decompression led to a statistically significant reduction of the palpebral fissure of about 11% (p < 0.001). OSA correlated with lid aperture pre and post surgery (p < 0.001). The extent of OSA reduction showed no correlation with the amount of exophthalmos reduction.

Our results show that surgical decompression, besides correcting exophthalmos, leads to a significant reduction of scleral show and lid aperture. However, it is not possible to estimate its effect on an individual basis.