Optic disc pit (ODP) is a rare congenital colobomatous anomaly of the optic nerve that occurs with an incidence of 1 in 1,100.1,2 Although it is often asymptomatic, ODP may result in visual field defects or progressive central visual loss in the presence of ODP maculopathy (ODPM). This entity may cause serous macular detachment with or without schisis of the inner and outer retinal layers, resulting in severely reduced vision and progressive inner-retinal and outer-retinal atrophy.2,3 The origin of submacular fluid in ODPM is debated and may represent cerebrospinal fluid from the subarachnoid space (that enters through the optic disc pit), subretinal fluid from vitreous entering the subretinal space, subretinal fluid related to schisis fluid from glaucomatous cupping, or subretinal fluid from peripapillary blood vessels or from the choroidal circulation that enters through Bruch’s membrane.1-7
Several surgical techniques, including pars plana vitrectomy (PPV) with and without laser, gas tamponade, and/or internal limiting membrane (ILM) peeling, have been reported with variable success rates.1,4,8,9 However, current surgical techniques are associated with delayed reattachment, long recovery times, and recurrent maculopathy. Our surgical technique in treatment of ODPM employs intravitreal Tisseel glue (Baxter Healthcare Corporation) in combination with PPV, ILM abrasion, and gas tamponade for serous macular detachments associated with ODPs.
A standard PPV with the Constellation vitrectomy system (Alcon) is performed using intravitreal triamcinolone acetonide to stain and highlight the vitreous. In all cases, it is essential that the core vitrectomy is followed by posterior hyaloid separation using either the vitreous cutter or the silicone-tipped cannula. The posterior vitreous detachment (PVD) is carefully extended around the optic nerve, across the macula, and into the mid-periphery. Next, a Tano diamond-dusted membrane scraper (DDMS; Bausch + Lomb) is used to brush over the macula and to the optic nerve to remove surface membranes that stain with intravitreal triamcinolone. Tisseel fibrin sealant glue is prepared according the manufacturer’s instructions. Following air-fluid exchange, fibrin glue is dripped over the optic nerve. Then, a gas-air exchange is performed with either 15% perfluoropropane (C3F8) or 20% sulfur hexafluoride (SF6). No peripapillary laser is needed. Patients are instructed to assume prone position for 3 to 5 days (Video).
Several surgical pearls are worth mentioning to maximize best possible anatomical and functional outcomes. First, it is important to recognize that, despite removal of the posterior hyaloid, frequently there are surface membranes, vitreous fragments, and cellular remnants in the peripapillary region (Figure 1). We have previously shown that these residual cellular fragments appear as strands on electron microscopy and this is similar to our previous findings in macular hole eyes, where creating a PVD was not sufficient to remove surface membranes with elastic properties.10 The preferred approach to ensuring removal of these persistent cellular fragments is for ILM membranectomy. Because these fragments are localized to the inner ILM and retina, abrasion with a Tano DDMS can remove these tractional elements from the macular and peripapillary areas. We have shown that this maneuver will remove residual membranes from the retinal surface and partially remove the ILM with minimal trauma to the underlying retina structures, which tend to be distorted from subretinal fluid and retinoschisis.10,11
Second, commonly we observe a vitreous strand penetrating into the optic pit that is visible with triamcinolone staining (Figure 2). This optic pit vitreous strand is not visible in the preoperative exam or imaging. We recommend using forceps to remove the vitreous strand extending from the optic pit. Chromovitrectomy using triamcinolone shows that, even in the presence of a PVD, the peripapillary vitreous may remain attached to the optic nerve and extend into the optic pit, usually temporally toward the macula. Persistent vitreous or glial tissue within the ODP cavity has previously been found in 89% of eyes intraoperatively and correlated with only 78% of eyes via optical coherence tomography preoperatively.5 These findings support the theories ascribing the origin of subretinal fluid in ODPM to the vitreous adhesions.4 Performing ILM abrasion of the peripapillary area successfully removes these persistent vitreal adhesions to the optic pit, which may otherwise create traction on the optic pit.
Third, Tisseel tissue glue facilitates closure of the pit; however, successful closure seems only to occur when the peripapillary adhesion fragments and vitreous strands are removed to relieve traction on the optic pit. Tisseel is widely used in ocular surgery with no directly reported retinal toxicity. Still, long-term studies in eyes with ODPM treated with tissue glue using electroretinography and progressive visual field testing may provide further insight into the long-term safety of its intravitreal use. The main drawback to the use of Tisseel and other fibrin glues is the potential risk of viral transmission and high cost.
This surgical technique is a viable approach to ODPM that provides relatively rapid postoperative improvements in both function and anatomy. In part, this rapid recovery reduces the risk of retinal pigment epithelium and retinal atrophy that may otherwise ensue following PPV without ILM peel and endolaser alone. This technique utilizing the ILM abrasion with the Tano DDMS, combined with the use of Tisseel glue, may be a viable alternative to closure of ODPs and aid in preserving adjacent retinal tissue. RP
- Rayat JS, Rudnisky CJ, Waite C, et al. Long-term outcomes for optic disk pit maculopathy after vitrectomy. Retina. 2015;35(10):2011-2017.
- Georgalas I, Ladas I, Georgopoulos G, Petrou P. Optic disc pit: a review. Graefes Arch Clin Exp Ophthalmol. 2011;249(8):1113-1122.
- Gass JDM. Serous detachment of the macula secondary to congenital pit of the optic nerve head. Am J Ophthalmol. 1969;67(6):828-841.
- Moisseiev E, Moisseiev J, Loewenstein A. Optic disc pit maculopathy: when and how to treat? A review of the pathogenesis and treatment options. Int J Retina Vitreous. 2015;1:13.
- Gregory-Roberts EM, Mateo C, Corcóstegui B, et al. Optic disk pit morphology and retinal detachment: optical coherence tomography with intraoperative correlation. Retina. 2013;33(2):363-370.
- Patel S, Ling J, Kim SJ, Schey KL, Rose K, Kuchtey RW. Proteomic Analysis of Macular Fluid Associated with Advanced Glaucomatous Excavation. JAMA Ophthalmol. 2016;134(1):108-110.
- Brown GC, Shields JA, Goldberg RE. Congenital pits of the optic nerve head. II. Clinical studies in humans. Ophthalmology. 1980;87(1):51-65.
- Hirakata A, Inoue M, Hiraoka T, McCuen BW 2nd. Vitrectomy without laser treatment or gas tamponade for macular detachment associated with an optic disc pit. Ophthalmology. 2012;119:810-818.
- Shukla D, Kalliath J, Tandon M, Vijayakumar B. Vitrectomy for optic disk pit with macular schisis and outer retinal dehiscence. Retina. 2012;32(7):1337-1342.
- Almeida DR, Chin EK, Tarantola RM, et al. Effect of internal limiting membrane abrasion on retinal tissues in macular holes. Invest Ophthalmol Vis Sci. 2015;56(5):2783-2789.
- Mahajan VB, Chin EK, Tarantola RM, et al. Macular hole closure with internal limiting membrane abrasion technique. JAMA Ophthalmol. 2015;133(6):635-641.