Serous Retinal Detachment in Dome-shaped Macula with 7 Years Follow-up.

Dome-shaped macula (DSM) was first described by Gaucher et al. as a convex protrusion of macula within a staphyloma in highly myopic eyes that cause visual impairment associated with serous foveal detachment (SFD). We describe a patient with persistent SFD in DSM documented by serial spectral domain optical coherence tomography for 7 years with stable vision.

Introduction

Dome-shaped macula (DSM) is known entity in myopic eyes reported to occur in up to 20% of high myopes.[1] The condition is described as a convex elevation of the macula within a myopic staphyloma.[2] It is thought to represent an adaptive mechanism to the scleral expansion that occurs in axial myopia.[3] Three different patterns have been described according to optical coherence tomography (OCT): round dome 20%, horizontally oriented oval-shaped dome 62.5%, and vertically oriented oval-shaped 16.7%.[4] Reported complications were choroidal neovascularizations (CNVs), lamellar macular holes, full-thickness macular holes, foveal, and extrafoveal retinoschisis.[1]

Serous retinal detachment (SRD) without choroidal neovascular membrane is a common cause of visual loss and metamorphopsia in DSM.[2] The range of refractive error and axial length of the eyes with DSM and SRD is variable; it is generally associated with highly myopic eyes although emmetropia and hyperopia have been reported.[5] Features associated with SRD include highly elevated macular bulge, thicker macular choroid, vertically oriented oval-shaped domes, and retinal pigment epithelial (RPE) disturbances.[5] DSM is associated with multiple hereditary retinal and vitreoretinal dystrophies, but no other ocular or systemic associations have been described with this condition except a single case with concurrent glaucoma.[5] To date, however, there is no effective therapy for serous foveal detachment (SFD) associated with SRD though trails of photocoagulation of accessible angiographic leaking areas, intravitreal injection of bevacizumab, and photodynamic therapy showed variable success.[6]

Case Report

A 47-year-old diabetic Type-2 male presented with blurry vision in both eyes. Best-corrected visual acuity was 20/40 oculus dexter (OD) and 20/30 in oculus sinister (OS); refractive spherical equivalent − 4.75D OD and − 5.25D in OS; axial length was 27.0 mm in OD and 27.4 mm in OS. The intraocular pressure was 14 mmHg in OD and 15 mmHg in OS. Corneas showed central endothelial guttate with pigment deposits which clinically resembles Fuch's corneal endothelial dystrophy, in addition, he had bilateral visually insignificant posterior subcapsular cataract. Fundus exam in both eyes showed posterior staphyloma with macular RPE circular changes of similar pattern and horizontal ridge connecting the optic disc and the fovea in both eyes [Figure 1]. Optic discs were horizontally oriented with large cupping, and there was no diabetic retinopathy. Gonioscopy revealed open angles with hyperpigmented trabecular meshwork and a glaucomatous visual field defect. Specular microscopy demonstrated low corneal endothelial cells count. Spectral domain-OCT (Heidelberg Engineering GmbH, Heidelberg, Germany) depicted subfoveal fluid with convex configuration of the macular region resembling macular bulge within the concavity of the posterior staphyloma [Figure 1]. Enhanced depth imaging (EDI) OCT showed thinned subfoveal choroid compared to the perifoveal region.

Figure 1

(a and b) Fundus photos showing myopic changes and the arrow pointing to horizintal ridge connecting the disc and fovea, (c and d) optical coherence tomography showing the macular bulge and serous foveal detachment, (e) corneal diffuse light showing Krungberge spindle, (f) specula microscopy, (g) gonioscopy showing hyperpigmented trabecular meshwork

The patient was diagnosed as SFD in DSM, pigmentary glaucoma, and Fuchs corneal endothelial dystrophy and was offered half-fluence verteporfin photodynamic therapy but favored no intervention.

During the 7 years of follow-up, he underwent cataract surgery secondary to the development of visually significant cataract in both eyes. This was followed by descemet automated endothelial stripping keratoplasty for corneal decomposition in both eyes.

Interestingly, during the follow-up period, his SFD did not show any progression. Clinical and serial OCT demonstrated the same amount of subfoveal fluid even after these interventions. Fluorescein angiography (FA) showed few leaking points in the fovea in both eyes at the retinal pigment epithelium level corresponding to RPE disturbances in addition to the window defect resulting from RPE atrophy at that area [Figure 2]. The final visual acuity was 20/40 OD 20/30 in OS.

Figure 2

(a and b) Optical coherence tomography showing the macular bulge and serous foveal detachment. Corneal diffuse light showing Krungberge spindle, (c) fluorescein angiography showing earliest photo showing window defect at with minimal leak at the level of retinal pigment epithelial and (d) most recent fluorescein angiography showing no significant change

Discussion

The pathophysiology of SRD in DSM to date is uncertain. It has been attributed to different factors. RPE dysfunction and fluid obstruction caused by scleral thickening as in cases of Nanophthalmos.[2] Errera et al.[5] reported cases of SRD in DSM without CNV and showed higher choroidal thickness in cases of SRD similar to what has been reported in central serous chorioretinopathy. Viola el al.[3] elucidated that the mechanism of SRD is likely caused by choroidal vascular changes secondary to excessive thickening of the sclera shown by swept source OCT, intravenous FA, and indocyanine green. In addition, his study showed fluctuating changes of SRD over time, with alternating active and inactive stages.

In our patient, we observed few fluorescein leaking points at the level of RPE, but EDI-OCT showed thinning in subfoveal choroid in the macular bulge area with in contrast to the proposed mechanism of choroidal vascular thickening at the area of macular bulge in SRD.[3]

It is worth to mentioning that similar cases have been treated with focal laser, intravitreal antivascular endothelial growth factors agents, spironolactone, and half-fluence photodynamic therapy showing better results with the latter two.[6] Interestingly, tamura reported a spontaneous resolution of SRD after 3 months of observation.[6] Nevertheless, in our case, the patient had persistent SRD, which was stable for 7 years with regular follow-up.

The association of pigmentary glaucoma and myopia has been documented. However, we did not find any association between Fuchs endothelial dystrophy and myopia.[7]

This will be the first reported case that showed such association, which could be coincidental finding; however, we believe that such association has no role on the pathogenesis of SRD.

Conclusion

We report the first case of DSM with stationary persistent SFD and subfoveal fluid for 7 years without visual deterioration. Based on the importance of this clinical finding, we suggest that observation without intervention can be the management option for this condition. However, we believe that further understanding the pathogenesis of SRD in this condition would help in determining the best method of treatment in each situation.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.