Use of saliva flow rate measurement in minor salivary glands autotransplantation for treatment of severe dry eye disease

Abstract

Aims: To use minor salivary glands' flow rate (MSGFR) measurement in minor salivary glands (MSGs) autotransplantation for the treatment of severe dry eye disease (DED).

Methods: MSGs autotransplantations were performed in 18 eyes (17 patients) with severe DED. MSGFR were measured before operation. The upper or lower lip with higher MSGFR was selected as the donor site. Buccal mucosa was the back-up in cases labial MSGs showing markedly decreased MSGFRs. Two pieces of salivary lobules with the covering mucosa were harvested and transplanted to the recipient beds prepared in both upper and lower lids.

Results: The donor sites included lower lip in 12 eyes, upper lip in 5 eyes and buccal mucosa in 1 eye. Postoperative follow-up confirmed viable grafts in all cases. The overall subjective relief rate of DED symptoms was 58.8%, with Schirmer test values increasing from 0 mm to 4 mm (p<0.05). The mean preoperative MSGFR was 1.7 (range: 0.9-3.3) µL/min/cm². ROC analysis indicated an outstanding discrimination power for preoperative MSGFR to predicate postoperative relief of DED symptoms (area under the curve (AUC)=0.948, p<0.01). The maximum sensitivity (100%) and specificity (72.7%) were reached at a cut-off of 1.785 µL/min/cm². Patients with preoperative MSGFR >1.785 µL/min/cm² showed greater improvement of Schirmer test values after surgery than those with MSGFR ≤1.785 µL/min/cm² (p<0.05).

Conclusion: MSGs transplantation proved to be useful for treating severe DED. The amount of postoperative lubrication and the treatment effect were positively correlated with preoperative MSGFR. MSGFR measurement and donor-site selection should be critical steps before the operation.

Keywords: lacrimal gland; ocular surface; tears; treatment surgery.

Figure 1

Measurement of the salivary flow rate of minor salivary glands and harvesting of the grafts. (A) Measurement of the salivary flow rate of the donor sites. (B) Observing the donor site to determine the area containing most salivary drops (arrows). (C) Determining the graft’s final location according to step B and harvesting of the graft. (D) The incision depth of harvesting the graft (branches of the trigeminal nerve were marked with arrows). (E) The wound of the donor sites (the nerves were marked with arrows). (F) Grafts.

Figure 2

Graft transplantation and patients follow-up. (A) Photo of the dry eye taken before the operation. (B) Preparation of the recipient bed. (C) Fixation of the graft to the recipient bed. (D and E) Four years’ follow-up of the grafts. (F) Four years’ follow-up of the treated eye. The presence of the moisture content on the ocular surface.

Figure 3

Repair of the donor wound and patients follow-up. (A and B) The repair of the lower lip’s wound with acellular dermal matrix (arrows), and 4 years’ follow-up. (C and D) The repair of the upper lip’s wound with acellular dermal matrix (arrows), and 6.5 years’ follow-up. (E) The repair of the wound of the lower lip with local rotational buccal flap. (F) Direct close of the wound of the buccal mucosa.

Figure 4

Preoperative and postoperative ophthalmic measurements. (A) Schirmer test values. (B) Fluorescent staining scores. (C) Best-corrected visual acuity. *P $\S amp;lt;$ 0.05.

Figure 5

ROC curve of preoperative MSGFR used to predict postoperative relief of DED symptoms. The area under the curve (AUC) was 0.948 (SE=0.050, 95% CI=0.850 to 1.000, p=0.002). The optimum cut-off point was defined as the closest point on the ROC curve to the point (X, Y) = (0, 1), where X=1-specificity and Y=sensitivity, indicating an outstanding discrimination power for preoperative MSGFR to predicate postoperative relief of DED symptoms. The optimum cut-off point of preoperative MSGFR was 1.785 μL/min/cm². DED, dry eye disease; MSGFR, salivaryflow rate of minor salivary glands.