Entropion is an in-turning of the eyelid margin associated with the eyelashes abrading the corneal surface with ulceration, and if left untreated, eventually opacification and visual loss. It can be seen as an acquired condition in adults, or as a congenital malposition. Congenital upper eyelid entropion, in general, was first described in 1841 by von Ammon.¹ Later cases were mentioned by Wilde,² Lippincott,³ Chow,⁴ and Redslob,⁵ among others, but these early descriptions do not allow determination of specific etiologies.

Congenital entropion is typically present at birth or becomes evident within the first few weeks or months of life. It is exceedingly rare and mostly involves the lower eyelid in the form of epiblepharon. Congenital entropion of the upper eyelid is even rarer with only a small number of cases reported. The etiology can be secondary or primary. Secondary congenital entropion is acquired as a result of trauma, chemical conjunctival burns, infections, inflammatory conditions, and hereditary cicatricial disease, or it is associated with genetic anomalies such as cutis laxis⁶,⁷ or progeroid syndrome.⁸ Primary congenital upper eyelid entropion results from developmental or intrauterine processes and has been related to absent tarsal plates, fibrosis, and shortening of the levator aponeurosis, a thickened tarsus with an extra row of meibomian glands, or absence of the eyelid crease with loss of fixation of the anterior lamella to the tarsus.⁹ When the tarsal plate is present, it usually is described as being normal.¹⁰

One well-defined form of primary congenital entropion has been referred to as the congenital horizontal tarsal kink, characterized by a horizontal depressed crease across all or part of the posterior surface of the upper tarsal plate. It was originally described in 1948 by Kettesy,¹¹ who speculated that inflammatory edema of the superior conjunctival fornix for several weeks in utero mechanically folded the tarsus into a fixed position. The tarsal deformity results in an inversion of the eyelid margin that causes corneal epithelial erosion, infectious keratitis, or corneal ulceration. The condition is usually diagnosed in children during the first several weeks or months of life. However, recognition of this condition is sometimes delayed, either because of initial misdiagnosis or because of subclinical findings that only progress with time.

Congenital tarsal kink is very rare with only about 48 cases described in the literature since 1948. Of the 25 cases where age data are available, the mean age at presentation was 24 weeks (range: birth to 240 weeks), with a median of 5 weeks. The condition is bilateral in 25% of cases, and when unilateral, the condition involves the right side more frequently than the left (48% vs 27%). Of the 19 cases where the race was reported, 84% were in Caucasians. Males are affected more frequently than females in a ratio of 3:1 (74% male, 26% female).

In a review in 1969, Hiles and Wilder¹² reported six cases of primary congenital upper eyelid entropion associated with cardiovascular, musculoskeletal, and central nervous system abnormalities. Zak¹³ also described a case of upper eyelid entropion associated with multiple systemic anomalies, including dysmorphic facies, micrognathia, abnormal feet, agenesis of the corpus callosum, and ventriculoseptal defect. Dailey et al¹⁰ presented a case of congenital upper eyelid entropion associated with a congenital heart defect. It has been proposed that, unlike primary congenital upper eyelid
entropion, tarsal kink is not associated with systemic abnormalities.¹⁴ However, Batur et al¹⁵ reported a case of bilateral tarsal kink in an infant with Wiedemann-Rautenstrauch syndrome, an extremely rare, autosomal recessive disorder characterized by progeroid appearance, macrocephaly, wrinkled skin, reduced subcutaneous fat, and neonatal teeth. Lucci et al¹⁶ described a case of unilateral tarsal kink in a child with trisomy 13 (Patau syndrome) having multiple craniofacial, cardiac, neurologic, and renal anomalies, and El-Mulki et al¹⁷ presented a case of bilateral tarsal kink with hydronephrosis. Naik et al¹⁸ and Pushker et al¹⁹ provided one case each of tarsal kink associated with microphthalmos.