A 15-year-old boy underwent pars plana vitrectomy and lensectomy following blunt closed-globe injury. Postoperatively, he had visual distortion and a decline in visual acuity attributable to tractional macular edema caused by clinically apparent residual vitreous cortex. One month later, macular edema resolved and visual acuity improved following spontaneous vitreous separation. This case illustrates what has been termed the posterior bursa macularis and emphasizes its pathoetiologic role in vitreomacular disease.
Resolution of Tractional Macular Edema Following Spontaneous Detachment of Residual Vitreous Cortex in a Vitrectomized Eye
From Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee.
Address correspondence to Franco M. Recchia, MD, Division of Vitreoretinal Diseases and Surgery, Vanderbilt Eye Institute, 8018 Medical Center East, Nashville, TN 37232.
Accepted: May 21, 2007
Posterior cortical vitreous is thought to play a significant role in disorders in which vitreomacular traction is intrinsic to their pathogenesis, such as macular holes and diabetic macular edema.1 On the basis of autopsy ultrastructural studies, some authors have defined a dome-shaped lacuna (bursa premacularis) with an anterior border of the formed vitreous and a posterior border of a thin layer of cortical vitreous tightly adherent to the macula.2 Although it has been well-documented intraoperatively,3–4 this posterior vitreoretinal adhesion is difficult to see in living eyes under normal conditions. We report a case of a vitrectomized eye in which residual vitreous cortex, possibly representing the posterior bursa premacularis, was easily visible by slit-lamp biomicroscopy and optical coherence tomography as an illustration of this important anatomic finding and its pathogenetic implications.
A 15-year-old boy was referred for treatment of traumatic hyphema, subluxated cataract, and vitreous hemorrhage in the left eye following a bottle rocket injury 1 week earlier. He underwent uncomplicated pars plana vitrectomy and pars plana lensectomy. Intraoperatively, the posterior hyaloid was disinserted from the optic nerve using active suction and appeared to be completely detached from the macula. Triamcinolone acetonide was not used.
One month postoperatively, the patient complained of a “floating spot” in the central vision of his left eye. Best-corrected visual acuity was 20/200 in the left eye. Funduscopy showed a well-delineated oval of vitreous approximately 4 disc areas in size that was partially attached to the central macula and accompanied by macular edema (Fig. 1A). The patient and his mother elected observation as the treatment method. One month later, best-corrected visual acuity was 20/80 in the left eye. Funduscopy showed a complete detachment of the residual vitreous cortex, which was seen floating in the anterior vitreous cavity, and underlying pigmentary changes in the fovea (Fig. 2A).
Figure 1. (A) Color Fundus Photograph of the Left Eye of a 15-Year-Old Boy 1 Month Following Pars Plana Vitrectomy Showing Residual Vitreous Cortex and the Posterior Face of the Bursa Macularis. Vitreous Is Attached to the Macula Superiorly and Detached from the Macula in the Inferotemporal Area. Visual Acuity at This Time Was 20/200. (B) Corresponding Horizontal 6-mm Optical Coherence Tomography Scan Showing Residual Vitreomacular Attachment and Macular Edema.
Figure 2. (A) Color Fundus Photograph of the Left Eye 2 Months After Vitrectomy Showing Spontaneous Detachment of the Residual Vitreous Cortex. Underlying Macular Pigmentary Changes Most Likely Resulting from the Original Closed Globe Injury Are now More Evident. Visual Acuity at This Time Was 20/80. (B) Corresponding Horizontal 6-mm Optical Coherence Tomography Scan Showing Complete Vitreous Detachment and a Foveal Depression.
The posterior face of the bursa premacularis is an elusive structure in living eyes. This premacular vitreous cortex may contribute to changes in macular anatomy and visual loss if there is traction exerted on the fovea. In the current case, optical coherence tomography demonstrated vitreomacular traction associated with residual cortical attachment (Fig. 1B) and resolution of the traction after the release of the vitreous cortex (Fig. 2B).
The case also reminds the vitreoretinal surgeon that it is possible to leave cortical vitreous even after what was perceived as complete vitrectomy.4 This fact is important in cases in which complete removal of premacular cortical vitreous is crucial to therapeutic effect, such as macular hole, diabetic macular edema, or vitreomacular traction syndrome. To ensure complete removal, some have suggested the intraoperative use of triamcinolone acetonide, which facilitates visualization of residual vitreous following vitreous separation.4
It is interesting that residual vitreous can contribute to macular traction even after vitrectomy and release of antero-posterior tractional forces, suggesting that traction can be exerted by intrinsic elements such as contractile collagen. Also, spontaneous release of cortical vitreous is possible after vitrectomy, suggesting that local changes at the vitreomacular interface (and not exclusively antero-posterior vitreous contraction) may contribute to posterior vitreous detachment.
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