Modified Technique For Preserflo Implant Surgery In Glaucoma. Prospective Case Series With 3 Years Follow Up.

Filtration surgery with Preserflo implant is considered a minimally invasive glaucoma surgery (Santen SA, Japón). The knowledge about its long-term safety and efficacy is limited. Our group believes the Preserflo surgical technique may be refined by an oblique and more posterior implantation, the use of a collagen matrix over the implant and under the tenons’ capsule, and a 6-month period of corticosteroid topical treatment. The purpose of this study is to present and assess long term safety and efficacy of a modified Preserflo implant surgical technique.

Prospective case series of glaucoma cases who needed surgery with Preserflo implant alone or together with phacoemulsification in a large multispecialty ophthalmic clinic in Barcelona (Spain). Surgeries were performed by two glaucoma surgeons with over 20 years of experience.

Forty-nine cases with open angle glaucoma underwent Preserflo surgery, and 26 of them received also phacoemulsification. All patients underwent slit lamp observation,IOP measurements, Humphrey visual fields, OCT images, pachymetry and gonioscopy. Examinations at 1 month, 6 months, 1 year, 2 years and 3 years was used for this study.  All participants signed an informed consent. Postoperative treatment consisted of antibiotics for 1 week and corticosteroids for 6 months. Postoperative maneuvers were performed as indicated by the surgeons. Hypotensive medications were discontinued at surgery and prescribed if needed to reach target IOP. Quantitative variables were compared overtime with Wilcoxon test and between groups with Mann Whitney test.

Participants had a mean (± SD) age, mean defect, IOP and number of medications were 73.6 (10.1) years, -11.1 (8.4) dB, 22.9 (7.7) mmHg and 3.3 (0.7) drugs, respectively. IOP was significantly (p<0.001) lower at 1 year (14.4 ± 4.5 mmHg), 2 years (13.3 ± 2.9 mmHg) and 3 years (13.1 ± 2.9 mmHg).The number of medications lowered with surgery  (p<0.05), being 0.7 ± 1.1 drugs at 3 years. . Complications identified were 1 suture dehiscence (2%), 1 hyphema (2%), 12 transient hypotony (IOP < 6 mmHg; 24%); and 5 peripheral choroidal detachments (10%). Postoperative maneuvers included 6 revisions (12%) and three 5-fluoroucacil injections (6%). All but 1 patient (98%) had IOP under 18 mmHg and needed less medications than before surgery.

The proposed modified surgical technique for Preserflo implant glaucoma surgery resulted safe and efficacious in this limited case series at 3 years. Contrarily to what has been reported about trabecular MIGS, Preserflo implant surgery seems to be as efficacious, or even more, when performed as a stand alone procedure than in combined surgery.