Pseudophakic Cystoid Macular Edema (PCME): The Central Role of Lens Removal and Anterior Uveal Remodeling

Sung who ParkKorea (Republic of) Speaker Pseudophakic Cystoid Macular Edema (PCME): The Central Role of Lens Removal and Anterior Uveal RemodelingBackground: PCME, commonly manifesting 4 to 12 weeks following cataract surgery, is characterized by increased vascular permeability. While its high responsiveness to topical NSAIDs suggests prostaglandin involvement, key paradoxes remain: Why is PCME frequently induced by the relatively simple cataract procedure, yet rarely follows more invasive surgeries like vitrectomy or trabeculectomy? And how do topical NSAIDs achieve therapeutic efficacy at the macula despite anatomical barriers such as the cornea and continuous aqueous flow? Hypothesis and Methods: We hypothesize that the pathological trigger is not generalized surgical trauma, but the structural changes caused by crystalline lens removal. The replacement of the large, heavy crystal lens with a small, lightweight intraocular lens necessitates adaptive remodeling of the anterior uvea. We propose that this remodeling results in prostaglandin release from this key pathological structure. To verify this, we conducted two studies analyzing PCME incidence after vitrectomy alone versus phacovitrectomy. Results: Our findings demonstrated that PCME incidence is significantly higher following phacovitrectomy compared to vitrectomy alone, strongly implicating lens removal as the main trigger for the syndrome. Furthermore, PCME was effectively reduced by topical NSAID administration after phacovitrectomy but was not significantly affected by the same treatment following vitrectomy alone. Conclusion: PCME pathogenesis is redefined by circumstances changes induced by crystalline lens removal, leading to prostaglandin release mediated by the anterior uvea. This novel model challenges the traditional view that PCME is solely a consequence of non-specific surgical inflammation, offering a precise anatomical target for both research and prophylaxis.