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Subretinal fluid drainage during scleral buckling procedure key to closing retinal breaks
Scleral buckling still has a place in retinal detachment repair despite the advent of vitrectomy.
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Vitrectomy has become the procedure of choice for many forms of retinal detachment. However, scleral buckling procedures are still optimal in some situations, and, despite less exposure, mastering this technique is still essential for the young retinal surgeon. Chiara De Giacinto and her colleagues share their experience and tips for effective buckling surgery.
Anthony Khawaja, PhD, FRCOphth Chair of the SOE Young Ophthalmologists committee
Scleral buckling is an effective surgical technique for the repair of rhegmatogenous retinal detachment. This procedure is widely adopted even today, and an anatomical success rate of 77% to 98% has been reported.
Despite the progressive development of alternative methods of retinal detachment repair, such as vitrectomy, scleral buckling remains a valuable procedure in many instances, and it should continue to be a part of the education for young ophthalmologists specializing in retinal surgery.
Rhegmatogenous retinal detachment with any of the following features can benefit from scleral buckling surgery:
- Rhegmatogenous retinal detachment in phakic eyes
- Young patients with attached posterior hyaloid
- Single break
- Multiple but contiguous breaks
- Detachments due to dialysis without retinal tear
- Absence of or limited proliferative vitreoretinopathy
In patients with opaque media (ie, cataract, vitreous hemorrhage), total retinal detachment, significant vitreoretinal traction (ie, proliferative vitreoretinopathy, diabetic neovascularization) or a posteriorly located break, using a scleral buckle is usually insufficient to reattach the retina. In these cases, vitrectomy is the best surgical procedure to manage retinal detachment. However, buckling may be used as part of the surgical approach in addition to vitrectomy.
Scleral buckling procedure
The scleral indentation achieved with scleral buckling can be accomplished by a variety of techniques and materials.
The principle of scleral buckling is based on the need to collapse the anatomic space created between the detached sensory retina and the retinal pigment epithelium. This is performed by the inward indentation of the sclera from the exterior, creating a buckle that closes the retinal tear and consequently reduces the fluid underneath the separated layers, thus re-establishing their physiologic connection.
The fundamental goal of scleral buckling is the functional closure of all retinal breaks, so that normal physiological forces can maintain a permanent state of attachment. Drainage of subretinal fluid and scleral buckling will close the responsible break(s) immediately.
Local or general anesthesia can be used for performing scleral buckling. A 360° limbal conjunctival peritomy incision is usually made for encircling procedures, but a less extensive incision is performed for limited buckling procedures. Traction sutures are placed beneath the insertions of the exposed rectus muscles to facilitate the positioning of the globe. The surgeon should look for abnormalities such as anomalous vortex veins or scleral thinning (usually seen as abnormal graying) in the equatorial or pre-equatorial area. After examination of the sclera, the surgeon should carefully examine the retina 360° with binocular indirect ophthalmoscopy and scleral indentation in order to identify important lesions that were not noted preoperatively.
A localizing mark is made with a scleral marking device on the point of sclera overlying the anterior edge of the retinal break(s). The tip of the scleral marker is firmly pressed against the eye for a few seconds, and the pressure creates a temporary black mark on the sclera. Alternatively, a flat diathermy probe can be used, yielding a light burn. The localization site is immediately dried and touched with a marking pen because of the fast disappearance of the pressure effect or light scleral burn.
A 360° encircling silicone band is passed around the circumference of the globe and beneath the rectus muscles. The band is traditionally anchored with a single mattress suture with bites parallel to the limbus placed in the center of each quadrant. Segmental silicone explants are secured to the sclera with 5-0 non-absorbable synthetic (commonly nylon) suture attached to spatula needles with cutting tips, tied in a horizontal mattress configuration.
Localized scleral buckles may be radially or circumferentially oriented, and a combination of the two may be considered if more extensive buckling is required. Calipers may be used to measure the distance between the suture bites, and in general these should be 2 mm to 3 mm wider than the explant for a modest buckling effect and 4 mm to 8 mm wider for a relatively high buckle.
The rationale for drainage of subretinal fluid is twofold: to diminish intraocular volume so as to allow elevation of the buckle without difficulties with elevated IOP, and to allow the retina to settle on the elevated buckle by removing fluid from the subretinal space. Effective drainage of subretinal fluid places the retinal breaks in juxtaposition to the buckle, thereby facilitating closure of the breaks. Drainage is performed through a radial sclerotomy.
If a large tear is present, the sclera or the buckle and sclera overlying the break are indented. This maintains IOP and inhibits passage of intravitreal fluid to the subretinal space. The appearance of pigment granules suspended in the draining subretinal fluid usually indicates that the last of the subretinal fluid is exiting the eye.
Retrospective study
In 2015, we performed an observational retrospective study in 44 patients who underwent scleral buckling surgery at the University Eye Clinic of Trieste, Italy. We reviewed all the scleral buckling procedures associated with evacuative puncture performed over a period of 26 months by the same surgeon. High-definition video by an integrated camera to microscope was recorded during the surgery. The macroscopic characteristics of the spilling subretinal fluid were examined.
We observed spilling of pigmented deposits in the fluid from the evacuative puncture to be a common aspect in the surgical procedure. In all cases, we observed that this macroscopic feature was typical during the late phases of the drainage. Indeed, the indirect ophthalmoscopic evaluation assessed that the subretinal fluid was almost completely drained at that moment. In conclusion, macroscopic characteristics easily detectable by the surgeon can drive the surgical procedure in order to optimize the drainage of the subretinal fluid.
- For more information:
- Chiara De Giacinto, MD, can be reached at University Eye Clinic of Trieste, Ospedale Maggiore, Piazza dell’Ospitale 1, 34125 Trieste, Italy; email: chiaradegiacinto@gmail.com.
Disclosure: The authors report no relevant financial disclosures.