Modified self sealing sclerotomy for drainage of subretinal fluid during scleral buckling surgery

1 The Retina and Vitreous Service, Clinica de Ojos de Maracaibo, Maracaibo, Venezuela
2 Retina and Vitreous Service, Clinica Oftalmologica Centro Caracas, Caracas, Venezuela

Correspondence to:
Dr J Fernando Arevalo
Clinica Oftalmologica Centro Caracas, Centro Caracas PH-1, Av Panteon, San Bernardino, Caracas 1010, Venezuela; areval1@telcel.net.ve

Accepted for publication 9 July 2003

Keywords: drainage; scleral buckling; sclerotomy; self sealing; subretinal fluid

Drainage of subretinal fluid is probably the most dangerous step in scleral buckling surgery for uncomplicated retinal detachment. The most common complications include subretinal haemorrhage, retinal perforation, and vitreoretinal incarceration.1,2 Sclerotomy to drain subretinal fluid is traditionally made with a sharp blade, diathermy to the sclera and choroid is performed, followed by perforation of the choroid to allow drainage of subretinal fluid. Suture of the sclerotomy at the end of the procedure has been recommended to avoid retinal incarceration.

The purpose of this study was to determine the effectiveness and safety of a modified self sealing sclerotomy technique for drainage of subretinal fluid during scleral buckling surgery.

Patients and methods

Twenty consecutive patients undergoing scleral buckling for primary rhegmatogenous retinal detachment from two vitreoretinal surgery centres were enrolled in this prospective study. A scleral buckling procedure was performed using a circumferential scleral band (Mira 240, Mira, Waltham, MA, USA) sutured with the posterior border located 12 mm posterior to the limbus, and adding any necessary segmental sponges (Mira). Cryoretinopexy was performed using a CTU Ophthalmic Cryo Unit (Keeler, London, UK) to seal retinal tears. After surgery, sulfur hexafluoride (SF6) gas was used in all patients. The drainage site was chosen based on retinal elevation, as shown by intraoperatative retinal examination with indirect ophthalmoscopy. A 3–4 mm half depth scleral incision was created perpendicular to the limbus using an angled bevel up blade (Alcon Laboratories, Fort Worth, TX, USA) with its sharp advancing edge directed perperdicular to the scleral surface (fig 1A). With a crescent knife, a 3 mm tunnel incision was then made to create a scleral flap parallel to the limbus (fig 1B). The scleral flap was retracted, and a 27 gauge needle was used to perforate the scleral bed and choroid (fig 1C). Subretinal fluid was expressed (fig 1D) and dried with a cotton swab. In all cases, the surgical wound was inspected for adequate closure at the end of the operation. Drainage of subretinal fluid and complications associated with this technique were assessed by intraoperative binocular indirect ophthalmoscopy, and recorded on surgical reports and records from postoperative visits.

Figure 1 (A) A 3–4 mm half depth scleral incision is created perpendicular to limbus using an angled bevel up blade with its sharp advancing edge directed perpendicular to the sclera surface. (B) With a crescent knife, a 3 mm tunnel incision is then made to create a scleral flap parallel to the limbus. (C) The scleral flap is retracted, and a 27 gauge needle is then used to perforate the scleral bed and choroid. (D) Subretinal fluid is expressed and dried with a cotton swab.

Results

All 20 patients had self sealing sclerotomy that did not require suturing at the end of surgery. Treating the choroid with diathermy or cautery was not necesary in any case, and the planned needle drainage procedure was successful in all patients. Drainage was slow and gradual. No serious complications were linked to the drainage of subretinal fluid with this technique. Spontaneous drainage was seen in one patient with thin sclera, and two limited subretinal haemorrhage that did not migrate to the posterior pole were observed.

Comments

We describe the results and complications of 20 scleral buckling procedures for primary rhegmatogenous retinal detachments in which subretinal fluid was drained using a sutureless sclerotomy technique. A self sealing incision with a stepped wound construction is not new to ophthalmology. Cataract and vitreoretinal surgeons pioneered this technique as part of phacoemulsification cataract extraction and vitreous surgeries.3–5 Possible advantages to this type of incision include shortened operating time and reduced incidence of postoperative wound leak.

This new way of constructing the sclerotomy for drainage has many advantages, and we propose it as an alternative to standard sclerotomy incision to drain subretinal fluid during scleral buckling surgery for uncomplicated retinal detachments.

References

Hilton GF, Grizzard WS, Avins LR, et al. The drainage of subretinal fluid: a randomized controlled clinical trial. Retina 1981;1:271–80.

Wilkinson CP, Bradford RH Jr. Complications of draining subretinal fluid. Retina 1984;4:1–4.

Fine IH, Fichman RA, Grabow HB. Clear Cornea Cataract Surgery and Topical Anesthesia. Thorofare, NJ: Slack Inc, 1993.

Chen JC. Sutureless pars plana vitrectomy through self-sealing sclerotomies. Arch Ophthalmol 1996;114:1273–5.

Kwok AK, Tham CC, Lam DS, Li M, et al. Modified sutureless sclerotomies in pars plana vitrectomy. Am J Ophthalmol 1999;127:731–3.