Dry eye and ocular surface disease

Sight, surgical outcomes and, ultimately, patient satisfaction critically depend on the health of the ocular surface. The extraordinary complexity of the ocular surface is maintained by intricate homeostasis; destabilization of this equilibrium may result in devastating consequences. Eyelid disorders can instigate a deleterious cascade of events, effacing the integrity and functions of the ocular surface epithelia. In many disease processes (e.g., Stevens-Johnson syndrome, cicatricial pemphigoid, collagen vascular diseases, burns, or even chronic blepharitis), the fundamental pathophysiology produces dysfunctional tear film, anomalous ocular surface epithelia, and disfigured lids. Disruption of the tear film progresses to keratoconjunctivitis sicca. Potentially devastating consequences, such as corneal scarring, infection and blindness, may ensue. Similarly, a healthy ocular surface is an important prognostic factor for surgical outcome. Accordingly, in this special edition on dry eye and ocular surface disease (OSD), we endeavor to provide the anterior segment surgeons with information to manage OSD and ensure optimal eyesight, surgical outcome, and patient satisfaction. Current literature indicates that the outcome of cataract surgeries, especially premium IOL implantation, is governed by OSD. Preexisting OSD is associated with suboptimal visual outcomes and higher risks of postoperative complications. In this issue, Movahedan and colleagues1 reviewed the salient observation between OSD and cataract surgeries. The authors presented strategies to diagnose and manage these conditions pre- and post-operatively to ensure optimal outcome. Amniotic membrane is a versatile tool for ocular surface reconstruction. Katzman and Jeng2 discussed different management modalities for persistent epithelial defects. Nguyen et al.3 investigated the role of amniotic membrane as an adjuvant therapy in high-risk penetrating keratoplasty. The authors aimed to leverage the anti-inflammatory properties of amniotic membrane to rehabilitate the ocular surface and reduce graft rejection; however, no correlation was determined in this retrospective series. In severe ocular surface disorders, the loss of limbal epithelial stem cells, or limbal stem cell deficiency (LSCD), has many deleterious complications, e.g. LSCD is a leading cause of corneal blindness. The diminished regenerative capacity seen in LSCD is characterized by persistent epithelial defects, erosion and ulceration, conjunctivalization and neovascularization, and chronic inflammation. Lin and Yiu4 provided excellent review diagnostic approaches and treatment for dry eye disease. Tu5 performed a comprehensive review of the toxicity of current ophthalmic eye drops. He and Yiu6 reviewed various stem cell based approaches for treating LSCD as well as discussing future direction and challenges. A recent innovation, the prosthetic replacement of the ocular surface ecosystem (PROSE) scleral lens has been instrumental in restoring vision and improving patient satisfaction for a wide range of OSD, e.g. severe dry eye, graft versus host disease, exposure keratopathy, limbal stem cell deficiency, as well as corneal ectasia. In this issue, Chiu et al.7 presented that PROSE can improve vision in patients with Salzmann’s nodular degeneration. OSD is a challenging adversity for the ophthalmologists. Successful outcome and patient satisfaction require thorough evaluation utilizing appropriate clinical tools and comprehensive medical management. Surgical patients necessitate attentive pre- and post-operative management. Evolution in the field will continue to arm the surgeons with tools to manage this chronic devastating condition.