EyeWorld India June 2019 Issue

EWAP JUNE 2019 33 SECONDARY FEATURE destructive procedures have unpredictable IOP results with an increased risk of graft rejection. This applies also to micropulse, which in our experience in these complex cases has been less than POAG patients with regard to IOP control. 5 MIGS might work, but once you enter the anterior chamber, graft rejection is a risk. Trab or trab- like procedures are good for graft survival and IOP control but contraindicated (relative) in the presence of contact lens use secondary to the risk of infection. Finally, canaloplasty ab externo with 10.0 Prolene is for me the best procedure both for IOP control and graft survival, with no concerns for contact lens related issues, as there is no bleb. I have a series of patients in this category over the years with long-term success, and it is my preferred method in patients with PKPG,” Dr. Ayyala said. When it comes to combining these surgeries, experience counts. Dr. Berdahl thinks that endothelial/corneal replacement procedures and glaucoma surgery can be combined, however, with caution. “I have done a number of iStents [Glaukos, San Clemente, California] at the same time as DMEK. However, you need to Ài>ˆâi ̅>Ì Ì…iÀi V>˜ Li ÀiyÕÝ and heme, and that can make `œˆ˜} > ÛiÀÞ `ˆvwVՏÌ]» he explained. “The more conservative play is a DSEK. We have presented our data showing that it can be done successfully. 6 One of the things I like about the combined approach is that I am less worried about steroid-induced IOP spikes when there is a trabecular bypass stent. I would suggest using the procedure that is least likely to induce hyphema. If you’re doing it in combination with a cataract surgery, I would suggest doing the glaucoma procedure prior to removing the cataract so that the heme can be washed away and bleeding likely stopped by the time the endothelial transplant occurs.” The study, for which he was a co-investigator, involved combining DMEK or DSEK with a trabecular micro-bypass stent replacement, along with cataract surgery in 15 patients with Fuchs’ endothelial dystrophy, open angle glaucoma, and visually È}˜ˆwV>˜Ì V>Ì>À>VÌ° ˆÃ ÀiÃՏÌà showed a visual improvement to 20/40 and by at least two lines in 13 of the study patients, a decrease in medications from 0.9 to 0.7 (p=.8), and an average IOP decrease of 1.7 mmHg. Only one eye required a graft exchange and another required a glaucoma valve to better control IOP. 6 Each surgeon will have an individual approach to highly complicated surgical scenarios. Dr. Ayyala does not advise combining DSEK and glaucoma ÃÕÀ}iÀÞ `Õi ̜ ̅i `ˆvwVՏ̈ià in maintaining the air bubble in the anterior chamber needed ̜ yœ>Ì Ì…i }À>vÌ] «>À̈VՏ>ÀÞ when the glaucoma surgery in question is a trabeculectomy or GDD. On the other hand, canal- based procedures such as the iStent and Kahook Dual Blade (New World Medical, Rancho Cucamonga, California) may be combined with DSEK, although it is not always advisable since these procedures are associated ܈̅ÀiyiÝ Lœœ` ˆ˜Ìœ ̅i >˜ÌiÀˆœÀ chamber, which will complicate DSEK surgery. Dr. Ayyala follows his patients via good clinical evaluation, and he recommends serial endothelial cell counts. How to monitor “We monitor surgical glaucoma patients clinically and visually and on their regular glaucoma follow-up visits,” Dr. Berdahl said. “We will do an occasional pachymetry and endothelial cell count if the vision is suboptimal, which can be helpful, but I don’t think that there is an algorithmic approach to monitoring the corneal endothelium. The best thing to protect the corneal endothelium is good surgical technique, avoiding hypotony, and ensuring that any devices in the anterior chamber are far away from the corneal endothelium,” he said. EWAP References 1. Janson BJ, et al. Glaucoma-associated corneal endothelial cell damage: a review. Surv Ophthalmol . 2017;63:500–506. 2. Ayyala RS. Penetrating keratoplasty and glaucoma. Surv Ophthalmol . 2000;45:91–105. 3. Williamson BK, et al. The effects of glaucoma drainage devices on oxygen tension, glycolytic metabolites, and “iÌ>Lœœ“ˆVà «Àœwi œv >µÕiœÕÅՓœÀ in the rabbit. Transl Vis Sci Technol . 2018;7:14. 4. Ayyala RS, et al. Comparison of mitomycin C trabeculectomy, glaucoma drainage device implantation, and laser neodymium:YAG cyclophotocoagulation in the management of intractable glaucoma after penetrating keratoplasty. Ophthalmol . 1998;105:1550–6. 5. Yelenskiy A, et al. Patient outcomes following micropulse transscleral cyclophotocoagulation: intermediate-term results. J Glaucoma . 2018;27:920–925. 6. Stunkel M, et al. Outcomes of partial-thickness corneal transplantation combined with trabecular bypass stent implantation and cataract surgery. Presented at the 2017 ASCRS•ASOA Symposium & Congress. Figure 6. MST graspers are then used to remove the stent. (KIWTG 1P IQPKQ [QW ECP UGG VJG UVGPV KU ƃWUJ YKVJ VJG CPING CPF CYC[ HTQO VJG EQTPGC Source (all): John Berdahl, MD