[Evaluation the change of corneal epithelium thickness after pterygium excision with conjunctival autograft transplantation by Fourier domain optical coherence tomography].

Objective: To evaluate the change of corneal epithelial thickness after pterygium excision with conjunctival autograft transplantation by Fourier Domain Optical Coherence Tomography (FD-OCT) .

Methods: Twenty-two patients (24 eyes) with the diagnosis of primary pterygium were enrolled. They underwent pterygium excision combined with conjunctival autograft transplantation. Twenty-five volunteers (25 eyes) served as the normal control group. FD-OCT was performed preoperatively and 1, 2, 3, 5, 7 days postoperatively to measure the thickness of corneal epithelium at 1 mm and 2 mm anterior to the nasal or temporal scleral spur. Corneal fluorescein staining was performed simultaneously. Comparisons on the thickness of corneal epithelium were made between preoperative values and postoperative ones.

Results: The thickness of cornea epithelium at 1 mm anterior to the scleral spur was (43.81 ± 2.55) µm in normal subjects. At day 1 after surgery, corneal epithelial thickness at the same location was (21.28 ± 5.72) µm and then gradually increased to (39.94 ± 5.47) µm at day 7 postoperatively. All the difference on postoperative days had statistically significant (t = -17.69, -14.97, -10.63, -9.86, -3.15, P < 0.05) . The thickness of cornea epithelium at 2 mm anterior to the scleral spur was (40.50 ± 3.17) µm in normal subjects. At day 1 after surgery, corneal epithelial thickness at the same location was (24.02 ± 5.92) µm, and then gradually increased to (940.34 ± 5.69) µm at day 7 postoperatively. All the difference on postoperative days except day 7 had statistically significant (t = -12.08, -10.27, -6.18, -2.99, P < 0.05). Cornea epithelium at this location repaired sooner than that at 1 mm anterior to the scleral spur. At day 1 after surgery, corneal epithelium defect area were (39.31 ± 22.77) mm(2), and then decreased to (1.01 ± 1.72) mm(2) at 7 days (t = 6.68, 5.55, P < 0.05). At day 7 postoperative, 66.7% patients had a complete recovery of corneal epithelium with no fluorescein staining.

Conclusions: FD-OCT was the effective instrument for observing the change of limbus-peripheral cornea epithelium thickness.Within 7 days postoperatively, cornea epithelium restored almost normal. After pterygium surgery, limbus-peripheral cornea epithelium restoration showed the tendency from the central to peripheral cornea.