Customized sclerotomy improves macular access in Chinese eyes with axial length ≥ 28 mm.

PURPOSE: This study aimed to explore the relationship between axial length and ciliary body length, along with the potential anatomical variability among different races. Based on this, a new positioning for sclera incision in pars plana vitrectomy for patients with axial length ≥ 28 mm was proposed and evaluated for feasibility and safety. METHODS: 83 Chinese patients were enrolled. Pre-operative subjective refraction and axial length were obtained. The ciliary body length was measured intraoperatively. Data of Caucasian population from a published paper are also reviewed and analyzed. From all the enrolled Chinese patients, we selected 7 patients with axial length ≥ 28 mm and who needed vitrectomy for macular diseases. New technique was used to make scleral incisions, and they were followed up for at least 12 months. RESULTS: The temporal and nasal ciliary body length have significantly positive correlations with axial length (p < 0.001, r = 0.386; p = 0.001, r = 0.357). The range of temporal ciliary body length and nasal ciliary body length in Chinese with axial length ≥ 28 mm are 5.5-10.5 mm and 5.5-9.5 mm. The mean, range, variance and standard deviations of ciliary body length in Chinese are greater than Caucasian with axial length ≥ 28 mm (p = 0.00034; p = 0.04996). No surgical-related complications occurred in the 7 patients with adjusted incision sites. CONCLUSION: There is a significant positive correlation between axial length and ciliary body length in nasal and temporal quadrant. Compared to Caucasians, Chinese population with axial length ≥ 28 mm exhibit higher variability in the nasal and temporal ciliary body length. Therefore, positioning the scleral incision 2-3 mm anterior to the ora serrata facilitates safer access of surgical instruments to the macular. This novel technique is not only simple but also offers improved cost-effectiveness. TRIAL REGISTRATION: This study has been registered on the Chinese Clinical Trial Registry website, registration number: ChiCTR1800015732 (registration date: 17th April, 2018).