The approach to diagnosis and surgical treatment of Brown syndrome

Relevance Brown syndrome (BS) is a rare form of non-concomitant strabismus [1], which is often interpreted by practicing ophthalmologists as a paralytic form. Diagnosis of this condition is complicated by the fact that its clinical manifestations are similar to other oculomotor disorders. BS is characterized by V- and Y-shaped patterns, widening of the palpebral fissure on the affected side, and mild exophthalmos in adduction of the eyeball [2]. Binocular vision is not impaired in Brown syndrome [3]. This can lead to a delay in establishing a diagnosis and to an incorrect surgical approach. Treatment of congenital BS is surgical; isolated cases of spontaneous improvement have been described [4]. However, to date there is no unified approach to choosing the type of intervention and determining indications for surgical treatment [5]. Goal To create algorithms for differential diagnosis and approaches to surgical treatment of Brown syndrome. Material and methods The treatment and diagnostics of 99 patients with Brown syndrome for 13 years, from May 2010 to May 2023, were analyzed. Of the examined, 35 were men (35%) and 64 were women (65%). The average age was 7.19 ± 0.87 years; the oldest patient at the time of the study was 45 years old, and the youngest was 1.5 years old. All subjects underwent standard ophthalmological and strabismic tests. In children who could speak, the nature of vision was assessed using the Worth, Bagolini, and double Maddox tests. Surgical treatment was performed in 60 cases with unilateral and 5 cases with bilateral syndrome (a total of 65 patients aged 2 to 45 years; 69 eyes). Tenotomy and tenectomy of the superior oblique muscle were performed in 53 cases, and prolongation and recession with prolongation of the superior oblique muscle in 16 cases. Results The clinical signs were systematized, differential diagnostic algorithms and approaches to surgical treatment were created, which contribute to the timely detection of Brown's syndrome and the implementation of a step-by-step surgical intervention. The results are presented in the form of sequential action schemes (algorithms) that will help practicing ophthalmologists in making a diagnosis and determining the correct tactics of surgical treatment. Conclusion Brown's syndrome has specific differential signs and requires a certain surgical treatment tactics with a step-by-step approach. The created algorithms help to avoid mistakes in order to obtain highly functional and cosmetic results. Key words: Brown's syndrome; incompatible strabismus; paresis of the elevators; surgical treatment of strabismus; tenectomy; tenotomy