This study shows that lateral tarsal strip (LTS) procedure can be applied solely or simultaneously with other oculoplastic surgeries for indications like involutional entropion, lower lid laxity, lower lid retraction, and nasolacrimal duct obstruction.
Entropion and ectropion are ophthalmological terms for defects of eyelid positioning.(12) Entropion is unusual coiling of the lower eyelid margin, and ectropion is malposition of the eyelid in which the lower eyelid falls away from its normal position to the orbit, exposing the palpebral and conjunctiva.(2, 12) Involutional entropion and ectropion are the most common types of eyelid malposition seen in ophthalmology practices. In this study population, involutional lid factors accounted for about 40% of clinical indications for LTS procedure. Paralytic and cicatricial etiologies were rare (Table 2).
Involutional entropion is generally caused by horizontal laxity and a combination of lower eyelid retractor dehiscence and orbicularis muscle override.(11) The standard surgical correction for these conditions is the LTS procedure. LTS can address both tarsal lengthening and lateral canthal tendon laxity. By firmly attaching the tarsal strip to the internal lateral orbital rim, this procedure offers better fixation and helps prevent outward or inward rotation of the inferior tarsal plate and orbicularis overriding.(2)
The amount of lateral tarsal strip tightening required depends on the height of the fixation point at the internal orbital rim; we recommend 2mm above the lateral canthal angle (Fig. 2). A patient in our study who was concerned about unnatural correction of lower lid laxity underwent LTS lower than the usual fixation height. Three months after the surgery, the patient revisited our clinic because of recurrence (Fig. 3). Undercorrection with lower LTS fixation height is the main cause of recurrence. Thus, we performed revision of the lateral tarsal strip above the first fixation point, and there was no further recurrence.
Chang et al. proposed a useful augmented lateral tarsal strip tarsorrhaphy for paralytic ectropion.(7) During augmented LTS, the periosteum on the lateral orbital rim is exposed to higher than standard LTS. The longer tarsal strip is attached 5mm–8mm above the horizontal intercanthal line. The augmented tarsal strip produces a greater elevating effect through a longer strip attached to the higher internal orbital rim for paralytic ectropion.(7) We also suggest overcorrection of the lateral tarsal strip for lagophthalmos and lower lid retraction to reduce recurrence (Fig. 4). Overcorrection effectively reduces the vertical palpebral aperture when LTS alone is insufficient. Patients should be warned that the lower eyelid can appear very tight and over elevated. These initial unnatural appearances will decrease within several weeks to a stable position, and patients usually achieve good symmetry about six months after surgery.
Some authors suggest other procedures like the medial spindle procedure to correct ectropion along with the LTS procedure.(13, 14) However, we argue that LTS alone can sufficiently achieve both functional and anatomical success. Kam et al. compared symptomatic and anatomical improvement between LTS alone and LTS with medial spindle procedure. Functional and anatomical results did not differ significantly between the two operations.(5) Surgeons might overuse the medial spindle, and LTS alone is sufficient for correcting the vast majority of involutional ectropion cases. Advantages of performing LTS alone are speed, no danger of lid margin notching, minimal removal of lid tissue, and simultaneous correction of canthal malposition and lid shortening.(5) A short surgery time is crucial for a better prognosis in elderly patients because they cannot endure long periods in an uncomfortable position. Also, in consideration of a delayed wound repair process, minimally invasive procedures are needed for elderly patients.
To correct lower lid retractor disinsertion and orbicularis override, which also induce tarsal instability, skin muscle excision on the lower lid is important for correcting involutional ectropion (Fig. 5). Compared with a transconjunctival approach, the external approach using skin muscle excision can reduce entropion recurrence and create a cicatricial force during skin healing.(9) In this study, 29 patients (17.37%) with 34 eyelids (15.53%) who underwent skin muscle excision were the second most common group of patients receiving simultaneous surgeries (Table 3).
Functional epiphora is indicated as epiphora with no anatomical outflow blockage. In epiphora patients without lacrimal punctum obstruction and nasolacrimal duct stenosis, lacrimal pump dysfunction is the cause.(15, 16) Dysfunction of the lacrimal pump is generated by lower lid laxity, lower lid retraction, and orbicularis oculi muscle paralysis. LTS can strengthen the horizontal power of the lower eyelid and improve lacrimal pump function.(8) Also, LTS can improve functional success because it can restore the lower lid from the orbit, presenting the tear reservoir to the upper canaliculus during blinking and allowing proper drainage to the nasolacrimal duct.(5) In this study, 44 patients (17.81%) with lower lid laxity (Fig. 6) and 44 patients (17.81%) with lower lid retraction (Fig. 7) underwent LTS, and 50 patients (29.94%) underwent simultaneous LTS and endoscopic dacryocystorhinostomy (Tables 2 & 3).
Lateral tarsal strip is a relatively simple procedure, and complications are rare. The most common complaint from patients is mild tenderness and serous discharge at the lateral canthal site. These complaints mostly resolve within 1–2 weeks post-surgery. Other rare complications are lateral webbing (Fig. 8) and wound dehiscence. Patients undergoing LTS should be cautioned not to rub and stretch the tight lower eyelid when applying eye drops and ointments. Also, if the tarsal strip is placed too anteriorly, a gap between the eyelid and orbit might occur. To prevent this, modified Frost suture, which is a 6-0 silk suture passed through the eyelid margin and attached to the forehead, is useful.(17)
Limitations of this study include its retrospective and noncomparative nature, as well as a short follow-up period, which was a consequence of the population’s inability to comply with multiple postoperative visits.
In summary, lateral tarsal strip is a simple technique that allows tightening of the lower eyelid to correct horizontal laxity. LTS can be applied alone or simultaneously with oculoplastic procedures for various indications. To reduce recurrence rates, overcorrection with fixation of the lateral tarsal strip above the canthal angle is important.