Functional and anatomical results of vitreopapillary traction after vitrectomy

Abstract

itreopapillary traction (VPT)appears as a pseudopapilloede-ma with strong adhesions at the mar-gin of the optic disc and plays animportant role in a number of differ-ent diseases, including diabetic retin-opathy, central retinal vein occlusionor toxocara (de Bustros et al. 1987;Kroll et al. 1995; Karatas et al. 2005).Its surgical release by vitrectomy hasbeen debated in the past (Small et al.1989). We present a young patientwho developed serious VPT afterchronic panuveitis.A 21-year-old man complained ofdecreased visual acuity (VA) andmetamorphopsia in the left eye. Hismedical history was unremarkable,with no persistent hyaloid artery orprevious ocular blunt trauma.The eye was initially treated atanother university hospital with atro-pine ointments twice daily and withprednisolone acetate eight times daily.His best corrected Snellen VA was20⁄20 OD and 20⁄200 OS. Fundus-copy OS revealed a severe uveitisintermedia with numerous cells andvenous sheathing. After a sub-Tenon’sinjection of 20 mg triamcinolone, thesubject’s VA improved to 20⁄60 tem-porarily. A second opinion wasobtained 3 months later at anotheruniversity hospital specializing in uvei-tis disease. This examination revealedno signs of herpes infection (HIV, her-pes simplex virus [HSV], herpes zostervirus [HZV], varicella zoster virus[VZV]), other infections (Toxocaracanis, lyme borreliosis, Treponemapallidum, To. gondii) or rheumatoidinfections (antineutrophil cytoplasmicantibody [ANCA], antinuclear anti-body [ANA]).Due to increasing VMT, the sub-ject’s VA declined to 20⁄80 OS4 months later and he attended ourinstitution. The anterior segmentappeared normal with a clear view tothe fundus and no synechia. Biomicro-scopic examination disclosed strongepipapillary adhesions and elevationof the optic disc (Figs 1A and 2A).Optical coherence tomography (OCT)revealed persistent traction of densevitreous strands on the optic disc(Fig. 3A) and moderate thickening ofthe central retina.A pars plana vitrectomy withseparation of the posterior hyaloidand release of the vitreal traction onthe optic nerve head was performed(Fig. 1B). Examinations of the vitre-ous specimens obtained revealed nosigns of bacterial or viral infection.On careful examination we noted amarkedly improved retinal vascula-ture immediately after surgery(Fig. 2B). Three weeks later the sub-ject’s VA improved to 20⁄25 with novisible traction on OCT (Fig. 3B),while the foveal thickness remainedconstant during a follow-up of8 months.Vitreopapillary traction has beenproposed as a possible cause of tem-porary or chronic functional impair-ment (Katz & Hoyt 2005). Our casegives further evidence of visualimpairment due to VPT and immedi-ate functional improvement after sur-gical release. Tractional forceselongate the retinal nerve fibres andbend the central retinal vessels. Physi-cal deformation via stretching andthinning of the ganglion cell axons(neurogenic) reduces the anterogradelyor retrogradely axoplasmatic flow andaccounts for a sensory blockade ofneuroretinal signals by altering thevisual evoked potentials. Mechanicalrestriction and nourishing of the