Choroidal folds after 25 gauge transconjunctival sutureless vitrectomy

Main

Sir,

Pursuit for smaller wound incision, expedited postoperative recovery are always the core issues in ophthalmic surgical development. Transconjunctival sutureless vitrectomy (TSV) with 25 gauge (G) is a new approach in vitreoretinal surgery without the need of preparing conjunctival and scleral openings or closure.^{1, 2} The mean operative time had been shortened by 33.7% with this new vitrectomy system.^{1, 2} It was demonstrated to be safe in a retrospective series with only one eye had postoperative retinal detachment. ² We hereby present a case of choroidal fold after 25 G TSV secondary to ocular hypotony. Surgeons who want to introduce 25 G vitrectomy system into their practice should be aware of the possible complications.

Case

A 53-year-old man received 25 G TSV for a recurrent epiretinal membrane of his left eye (Figure 1a,b). The preoperative best-corrected visual acuity (BCVA) was 20/40. On postoperative day 1, intraocular pressure of 5 mmHg, diffuse conjunctival chemosis, shallow anterior chamber coupled with VA of hand movement were noted in the left eye. Fundal examination revealed 360° choroidal detachment. No cyclodialysis or clefting could be seen in ultrasonic biomicroscopy. Conventional treatment modalities including reformation of anterior chamber with viscoelastic, pressure patching, topical 1% atropine, and oral prednisolone (1 mg/kg/day) were tried. Intraocular pressure began to rise on day 6 and the choroidal detachment resolved subsequently. At 3 months after TSV, marks of choroidal fold persisted with residual metamorphosia and the BCVA was 20/40 (Figure 1c,d).

Figure 1

(a) Colour fundus photography showing recurrent epiretinal membrane in the left eye of Case 1. (b) Fluorescein angiography demonstrating the tortuosity of the paramacular vessels and the cystoid macular oedema. (c) Colour fundus photography of the right eye showing choroidal folds temporal to the fovea. (d) Fluorescein angiography showing the typical hypofluorescence and hyperfluoresence bands suggestive of choroidal folds and settled choroidal effusion.

In contrast to conventional 20 G cannula-entry pars plana vitrectomy, surgical as well as visual merits of 25 G TSV are attributed to smaller conjunctival and scleral incisions, less tissue manipulation, and obviated need for wound suturing.^{1, 2} Possible complications such as wound leakage and endophthalmitis, however, should be addressed.³ In fact, nearly 11.4% (four out of 35 eyes) of post 25G TSV patients experienced unexplained low intraocular pressure (≤7 mmHg) on postoperative day 1.¹ Gupta et al reported transient hypotony on the day after 25 G TSV and 14 of their 100 eyes required supplemental intraocular gas, air, or saline injection (Gupta A. ARVO Meeting, 2003, Abstract). Similar complication of choroidal detachment has also been reported with 23 G TSV in 2 out of 225 eyes of a series.⁴

Size of sclerotomy and presence of vitreous tuft at sclerotomy sites have been proposed to be factors related to the extent of self-sealing.² Nevertheless, we believe that other conditions like thinning of sclera in pathologic myopia, scarring, or necrosis of previous wound entry sites, excessive intraoperative manipulation are also important determinants in the 25 G TSV system.