Morphological changes after trabeculectomy in highly myopic eyes with high intraocular pressure by using swept-source optical coherence tomography

Abstract

Purpose: To investigate the effects of intraocular pressure (IOP) reduction on the eyeball shape in highly myopic eyes with high IOP.

Methods: This study included patients with an axial length ≥26.5 mm and high IOP ≥22 mmHg after receiving maximum medication, with successful trabeculectomy by a single surgeon, and who underwent swept-source optical coherence tomography (SS-OCT) examinations on preoperative and postoperative ≥3 months periods. Eight eyes of 7 patients were included in the analysis. The morphological changes in the eyeball that occurred pre- and post-operation were analyzed from the SS-OCT images.

Results: In 6 out of 8 examined eyes, the following apparent morphological changes in the posterior pole and/or peripapillary sclera were postoperatively detected on SS-OCT images: peripapillary scleral shrinkage, decrease in the lamina cribrosa depth, flattening of the peripapillary scleral insertion into the optic disc, decrease in the angle of the scleral protrusion temporal to the optic disc, and inhomogeneous change in scleral curvature of the posterior pole.

Conclusions and importance: We found that the shape of some eyes with high myopia and high IOP changed owing to the decrease in IOP. Eyeball deformities may be affected by high IOP, and IOP reduction might reduce scleral deformation in highly myopic eyes with high IOP.

Keywords: High myopia; Intraocular pressure; Posterior staphyloma; Scleral deformation; Trabeculectomy.

Fig. 1

Obvious change in the peripapillary sclera after trabeculectomy (Case 5R) A, B, Color photographs. C–H, Swept-source optical coherence tomography images. The peripapillary sclera is shrunk and shortened after surgery, and eventually the lamina cribrosa moved forward. Scale bar = 300 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 2

Obvious changes in the peripapillary and posterior sclera after trabeculectomy (Case 5L) A, B, Color photographs. C–H, Swept-source optical coherence tomography images. The angle of the scleral protrusion temporal to the optic disc decreased postoperatively (red arrowheads in A–D). The peripapillary sclera is shrunk and shortened and the prominence of the posterior sclera becomes less obvious, postoperatively in C–F. The angle between the sclera inserting into the optic disc and that at the opposite side becomes more flattened postoperatively in G and H. Scale bar = 300 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Obvious change in the eyeball morphology after trabeculectomy (Case 6) A, B, Color photographs. C–F, Swept-source optical coherence tomography images. There appear to be asymmetric changes in the sclera postoperatively. In areas where the sclera had increased the anterior displacement, the overlying choroid and RPE exhibits a ruffled appearance. Scale bar = 300 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 4

Slight changes in the peripapillary and/or posterior sclera after trabeculectomy A, Case 1. The protrusion edge is slightly more flattened postoperatively (red arrowheads). B, Case 3. The prominent posterior sclera is more flattened postoperatively. C, Case 7. The peripapillary sclera is shrunk and shortened postoperatively. Scale bar = 300 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)