The role of dry eye disease in the cataract and refractive surgery

Resumen

Dry eye disease (DED) plays an important role in ophthalmic procedures with refractive aims such as those involving the cornea or the crystalline lens, but also in the treatment of other conditions such as glaucoma. This thesis describes the application of minimally to noninvasive diagnostic DED tests recommended by the Tear Film & Ocular Society Dry Eye WorkShop II (TFOS DEWS II) to help improve the understanding of the impact of dry eye on refractive and visual outcomes in ophthalmic surgery. Intraocular lens surgery, in particular modern cataract and refractive lens-exchange (RLE) surgery, is the focus of the first section of the thesis. In fact, DED is not only present as a postoperative complication but can be also responsible for sub-optimal refractive and visual outcomes since the preoperative examination can be influenced by a depleted tear film. Literature review suggests little evidence of advanced tear film assessments in patients undergoing intraocular lens surgery and little information where DED findings are most important. Key findings were the Ocular Surface Disease Index (OSDI), Dry Eye Questionnaire 5-items (DEQ-5) and tear metrics such as non-invasive keratograph break-up time (NIKBUT), tear film volume (TMH) and tear osmolarity. In modern refractive surgery, post-operative DED is still problematic and a common complication after surgery. Recently, newer techniques have been introduced to improve visual outcomes whilst overcoming some limitations of more established procedures. In-vivo confocal microscopy was used to compare corneal nerve structure after SMILE with that seen after traditional laser-assisted in situ keratomileusis (LASIK). Results showed FS-LASIK surgery had more impact on DED symptomatology, TMH and NIKBUT and led to significant change to the corneal nerve fibre metrics considered than SMILE surgery. Glaucoma management with topical eyedrops can lead to deterioration of the ocular surface in most patients with DED issues in both signs and symptoms. Of the newer surgical procedures designed to control intraocular pressure reducing the need for topical management, minimally-invasive glaucoma surgery (MIGS) seems promising and could improve the homeostasis of the ocular surface in glaucoma patients. However, very little research on this topic has been published and a pilot investigation to explore the use of a diagnostic battery of tests for DED after MIGS was carried out. Reduction in IOP was achieved together with the reduction in DED symptomatology, increase of the tear film stability and ocular surface staining Improvement.In summary, research studies detailed in this thesis use advanced diagnostic techniques to understand the role of DED in patients undergoing ophthalmic procedures. They also explore which are the most important tests for identifying the impact of DED in ophthalmic surgery. Better diagnosis and management of DED in patients undergoing ophthalmic surgery leads to better outcomes.