Postoperative recurrence of pterygium has been the biggest problem for clinicians and patients. Repeated recurrence and surgery are bound to seriously damage the ocular surface structure, visual acuity, conjunctival sac stenosis, symblepharon and other serious complications[20]. The selection and manipulation of operation is the key to determine the recurrence of pterygium after operation. The new operative method introduced in this paper is helpful to further reduce the recurrence rate after operation. In clinical cases, we observed that recurrent pterygium often began to proliferate from the lacrimal fossa, pulling the conjunctiva and blood vessels into the head in the shape of a bundle, considering that the fascia tissue of the lacrimal fossa might be the starting site of postoperative recurrence[21]. Because the conjunctiva and fascia tissue of the lesion site of pterygium was most likely to remain here, and loosed connective tissue containing a large number of fibroblasts and rich capillaries, some of the fibroblasts might come from epithelial cells that underwent the conversion from epithelial cells to mesenchymal cells (epithelial-mesenchymal transition, EMT)[10, 22]. Therefore, we carried out very serious and meticulous removal of pterygium tissue and its inferior fascia tissue during the operation until the lacrimal fossa tissue and a small amount of adipose tissue were exposed. The connective fascia tissue containing a large number of fibroblasts and capillaries was removed to the greatest extent, and a superficial arc groove was formed in the lacrimal fossa during suture, which further blocked the proliferation of fascia. The recurrence of pterygium caused by residual fascia tissue hyperplasia was greatly reduced.
Stem cells should be taken from limbal tissue within 6 clock bits in order to avoid limbal stem cell deficiency in donor site[23]. In this paper, all conjunctival grafts are taken from the upper conjunctiva, the range is not more than 2 clock positions, and the front end of the graft reaches the end of the anterior elastic layer of the limbal vascular network. This method can ensure that part of the limbal grille tissue is taken as the seed cells of limbal stem cells, while retaining most of the normal structure of the limbal grille area, and does not affect the repair of bulbar conjunctiva and limbus in the sampling area. Therefore, it is called limbal stem cell sharing.
Postoperative pterygium may cause and aggravate dry eye symptoms, bring discomfort to patients, seriously affect the quality of life, and may affect the uniform coating of tear film with conjunctival tissue scar and relaxation after pterygium operation. Turkyilmaz [24] et al. compared the results of dry eye examination between 24 cases of recurrent pterygium after simple scleral resection and 50 cases of non-recurrent pterygium. It was found that the postoperative tear osmotic pressure was significantly improved in both groups. The tear osmotic pressure decreased after 12 months of pterygium recurrence. The authors infer that pterygium excision can improve tear film function.
Our 403 cases (420 eyes) were investigated before operation and 10 days, 1 month, 3 months and 6 months after operation. BUT, TMH, slit lamp photography and patients' conscious symptoms and appearance satisfaction were investigated. The results showed that the average preoperative BUT was 6.10 ± 0.09. 7.00 ± 0.15, 7.02 ± 0.09, 7.00 ± 0.11 and 7.12 ± 0.10 at 10 days, 1 month, 3 months and 6 months after operation, respectively.
The average value of BUT in each time period after operation was longer than that before operation, which indicated to the stability of tear film after operation was better than that before operation. The conjunctival graft of limbal stem cells was thin and smooth, and the method of close fitting and stable suture and fixation with scleral surface was beneficial to the recovery of ocular surface structure and increased the stability of lacrimal film. The abnormal rate of TMH was 10.95% before operation, 12.14%, 10.47%, 11.19% and 10% at 10 days, 1 month, 3 months and 6 months after operation, respectively. There was no significant difference in the number of eyes with normal and abnormal SIt before and after operation. The results showed that this operation had no clear effect on lacrimal secretion, and did not reflex increase the amount of lacrimal secretion due to postoperative inflammatory reaction and ocular discomfort caused by scar formation. The recurrence, scar proliferation of conjunctiva and corneal surface were observed and recorded by slit lamp photography. 95.47% of the patients had no difference between the appearance of postoperative eyes and normal eyes (recurrence index Grade 1). Only 1 case had vascular fibrous tissue hyperplasia invading transparent cornea, the recurrence rate of real pterygium (Grade 4) was 0.21%.
94.04% of the patients had smooth conjunctival tissue and no proliferative scar (Grade I). Fasciomatous scar proliferation was found in 0.71% of the patients (3 cases). 90.47% of the patients had no subjective symptoms such as foreign body sensation, photophobia and tears after operation, 7.16% of the patients had mild symptoms, and 1.09% of the patients had obvious symptoms.
We can conclude that full fasciectomy combined with autologous limbal stem cell sharing transplantation is a very good surgical method for the treatment of pterygium. Its advantages include a very low postoperative recurrence rate (0.21%), which is lower than the current statistical recurrence rate (0.36%)[25, 26]. From the aspects of postoperative BUT, slt, patients' conscious symptoms and appearance satisfaction, it has great advantages. The increase of postoperative tear film stability is beneficial to reduce the recurrence rate and symptoms of postoperative dry eyes, and at the same time, the postoperative appearance effect is satisfactory. It is also a very suitable choice for patients with beauty needs.