[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.