Uveal effusion syndrome (UES) is a rare syndrome causing idiopathic exudative detachments of the choroid, ciliary body, and retina. It is hypothesized to be caused by impaired vascular drainage usually associated with scleral thickening [1]. The condition was first described by Brockhurst in 1975 but the concept has basically remained the same even today.
The thickened sclera is often a result of abnormal collagen fiber which compresses/impinge the vortex vein causing disturbances in venous drainage [2, 3].
Gass further added that most of the primary idiopathic uveal effusion syndrome are likely to be related with such congenital sclera anomaly - while in some cases, UES could also occur due to abnormal vortex veins. Various ocular pathologies or states like postoperative hypotony, scleral buckling surgery or posterior scleritis could also give rise to UES [1]. Whatsoever the pathology, they all share the final common pathway which will ultimately lead to congestions of the choriocapillaris and choroidal vasculature resulting in accumulation of fluid in the subretinal/subuveal space [6, 7].
Nanophthalmos is a rare primary ocular disorder that occurs due to arrest of growth of the globe after the closure of embryonic fissure. It is characterized by narrow palpebral fissure, small orbit, deep-set globe and a short axial length with no gross structural defect. These eyes are hyperopic with normal or reduced corneal diameter. It usually occurs bilaterally and sporadically, but can also occur as an inherited form in either autosomal dominant or recessive pattern [3, 4].
The examination of such eyes usually shows crowding of the anterior chamber structures –which is mainly due to a high lens - to - eye volume ratio. This is one of the reasons why nanophthalmic eyes have predeliction to angle-closure glaucoma and uveal effusion [5].
Nanophthalmos is classified into mainly three variants - Nanophthalmic eye or type 1. The eyeball is small (average axial length 16 mm) and high hypermetropic (average + 16 diopters). In type 2 or non-nanophthalmic eyes, there is clinically evident abnormal sclera but the eyeball size is normal (average axial length 21 mm) with small refractive error. The type 3 or non-nanophthalmic variant has clinically normal sclera [7, 9]. The natural course of UES in each of these variants is variable and often associated with frequent relapses.
Most nanophthalmic uveal effusion was left conservatively treated in the past. However, with the availability of new drugs and surgical breakthroughs over time, various methods of management have been described. Medical treatments with systemic steroids and antimetabolites have also been used but with variable and questionable results [2].
Surgical procedure gained momentum and popularity when Brockhurst in 1980, described good surgical results with decompression of the vortex veins by scleral resection with sclerotomy [8, 9].
In 1983, a newer surgical approach- subscleral sclerectomy was introduced by Gass and Jallow [1]. However, this technique had its limitations as it was later demonstrated that it was effective only in Types I and II nanopthalmic eyes [10]. With developments of newer devices, in 2015, Yepez JB et al. mentioned use of Ex-PRESS shunt, a glaucoma implant (2- to 3-mm–long and 0.4-mm–diameter tube). They reported successful treatment of type 2 uveal effusion syndrome. The device shunted the aqueous humor from the anterior chamber into the subconjunctival space and lowered the IOP [11].
Despite all the advances and techniques, the surgery on nanophthalmic eyes is very unpredictable. But if left untreated, most of these patients usually tend to get worse with time [12]. Hence the dilemma to intervene or not exists even today. As no generalized consensus is available, the treatment option is advised to be kept as “individualized treatment” with anticipation of all the complications that may pursue.
Scleral windows or vortex decompressions are usually performed and surgeons usually perform partial sclerectomy in all the quadrants in these procedures. It is the surgeon’s preference of whether they want to perform the external drainage of subretinal fluid or not. Here we describe, 2 patients of UES due to nanophthalmos for whom we performed quadrantic (only two quadrants) scleral window surgery (vortex vein decompression) with subretinal drainage at a single setup and their outcomes.