Subthreshold Micropulse Laser for Long-Lasting Submacular Fluid after Rhegmatogeous Retinal Detachment Surgery


Purpose: To assess the safety and efficacy of subthreshold micropulse laser (SML) photo-stimulation in the management of persistent subfoveal fluid (PSF) after surgery for rhegmatogenous retinal detachment (RRD).

Methods: In this pilot study, 11 eyes of 11 patients (8 men, 3 women) with long-lasting (12–18 months) PSF after surgery for RRD were evaluated before and after photostimulation with subthreshold micropulse yellow laser. Ophthalmic examination included best-corrected visual acuity (BCVA), Amsler grid test, ophthalmoscopy, autofluorescence (AF), and optical coherence tomography (OCT) with measurement of central point foveal thickness (CPFT). Primary outcome was subfoveal fluid resolution and secondary outcome was BCVA improvement.

Results: The mean CPFT and BCVA were, respectively, 436.8 ± 28.8 μm and 0.25 ± 0.1 μm decimal equivalent (DE) before photostimulation and 278 ± 54.4 μm and 0.57 ± 0.2 μm DE after photostimulation, a statistically significant difference (P < 0.001). Nine (81.8%) eyes showed improved BCVA, disappearance of macular detachment on ophthalmoscopy, reduced retinal pigment epithelium distress on AF, and restored macular profile with no neuroretinal alterations on OCT scans.

Conclusion: Although PSF after RRD surgery is often a self-limiting disease, our results suggest that SML photostimulation may be effective and safe in patients with clinically significant long-lasting PSF. Larger case–control studies are necessary to confirm these results.


Optical Coherence Tomography, Retinal Pigment Epithelium, Rhegmatogenous Retinal Detachment, Subretinal Fluid, Subthreshold Micropulse Laser

1. Marmor MF. Ryan’s retina. In: Schachat R, editor. Mechanisms of normal retinal adhesion. Volume III. St. Louis: Mosby; 2006. p. 1891–908.

2. Gharbiya M, Malagola R, Mariotti C, Parisi F, De Vico U, Ganino C, et al. Spectral-domain optical coherence tomography analysis of persistent subretinal fluid after scleral buckling surgery for macula-off retinal detachment. Eye 2015;29:1186–1193.

3. Benson SE, Schlottmann PG, Bunce C, Xing W, Charteris DG. Optical coherence tomography analysis of the macula after vitrectomy surgery for retinal detachment. Ophthalmology 2006;113:1179–1183.

4. Ricker LJ, Noordzij LJ, Goezinne F, Cals D, Berendschot T, Liem A, et al. Persistent subfoveal fluid and increased preoperative foveal thickness impair visual outcome after macula-off retinal detachment repair. Retina 2011;31:1505– 1512.

5. Reichstein DA, Larsen BP, Kim JE. Management of persistent subretinal fluid following retinal detachment repair. JAMA Ophthalmol 2013;131:1240–1244.

6. Veckeneer M, Derycke L, Lindstedt EW, Van Meurs J, Cornelissen M, Bracke M, et al. Persistent subretinal fluid after surgery for rhegmatogenous retinal detachment: Hypothesis and review. Graefes Arch Clin Exp Ophthalmol 2012;250:795–802.

7. Lanzetta P, Dorin G, Piracchio A, Bandello F. Theoretical bases of non-ophthalmoscopically visible endpoint photocoagulation. Semin Ophthalmol 2001;16:8–11.

8. Koinzer S, Elsner H, Klatt C, Porksen E, Brinkmann R, Birngruber R, et al. Selective retina therapy (SRT) of chronic subfoveal fluid after surgery of rhegmatogenous retinal detachment: Three case reports. Graefes Arch Clin Exp Ophthalmol 2008;246:1373–1378.

9. Ohkoshi K, Tsuiki E, Kitaoka T, Yamaguchi T. Visualization of subthreshold micropulsed diode laser photocoagulation by scanning laser ophthalmoscopy in the retro mode. Am J Ophthalmol 2010;150:856–862.

10. Stamer WD, Bok D, Hu J, Jaffe GJ, McKay BS. Aquaporin- 1 channels in human retinal pigment epithelium: Role in transepithelial water movement. Invest Ophthalmol Vis Sci 2003;44:2803–2808.

11. Berman ER. Mucopolysaccharides (glycosaminoglicans) of the retina: Identification, distribution and possible biological role. Bibl Ophthalmol 1969;79:5–31.

12. Edelman GM. Cell adhesion molecules. Science 1983;219:450–457.

13. Dorin G. Subthreshold and micropulse diode laser photocoagulation. Semin Ophthalmol 2003;18:147–153.

14. Lanzetta P, Polito A, Verritti D. Subthreshold laser. Ophthalmology 2008;115:216–216.e1.

15. Berger JW. Thermal modeling of micropulsed diode laser retinal photocoagulation. Lasers Surg Med 1997;20:409– 415.

16. Desmettre TJ, Mordon SR, Buzawa D, Mainster MA. Micropulsed and continuous-wave diode retinal photocoagulation: Visible and subvisible laser parameters. Br J Ophthalmol 2006;90:709–712.

17. Dorin G. Evolution of retinal laser therapy: Minimum intensity photocoagulation (MIP). Can the laser heal the retina without harming it? Semin Ophthalmol 2004;19:62–68.

18. Yu AK, Merrill KD, Truong SN, Forward KM, Morse LS, Telander DG. The comparative histologic effects of subthreshold 530-and 810-nm diode micropulse laser on the retina. Invest Ophthalmol Vis Sci 2013;54:2216–2224.

19. Inagaki K, Shuo T, Katakura K, Ebihara N, Murakami A, Ohkoshi K. Sublethal photothermal stimulation with a micropulse laser induces heat shock protein expression in ARPE-19 cells. J Ophthalmol 2015;2015:729–792.

20. Ricci FU, Mazzarelli P, Zonetti MJ, Missiroli F, Cesareo M, Pucci S. 810 nm micropulse laser irradiation selectively regulates VEGF 165 isoforms expression acting on RNA binding splice factor activation in indocyanine green loaded ARPE19 and caco2 cultured cells. Invest Ophthalmol Vis Sci 2010;51:409–415.

21. Wilson AS, Hobbs BG, Shen WY, Speed TP, Schmidt U, Begley CG, et al. Argon laser photocoagulation-induced modification of gene expression in the retina. Invest Ophthalmol Vis Sci 2003;44:1426–1434.

22. Flaxel C, Bradle J, Acott T, Samples JR. Retinal pigment epithelium produces matrix metalloproteinases after laser treatment. Retina 2007;27:629–634.

23. Harris JR, Brown GA, Jorgensen M, Kaushal S, Ellis EA, Grant MB, et al. Bone marrow-derived cells home to and regenerate retinal pigment epithelium after injury. Invest Ophthalmol Vis Sci 2006;47:2108–2113.

24. Caballero S, Kent DL, Sengupta N, Li Calzi S, Shaw L, Beli E, et al. Bone marrow-derived cell recruitment to the neurosensory retina and retinal pigment epithelial cell layer following subthreshold retinal phototherapy. Invest Ophthalmol Vis Sci 2017;58:5164–5176.

25. Landa G. Micropulse laser for persistent sub-retinal fluid in a patient previously treated for rhegmatogenous retinal detachment. Med Hypothesis Discov Innov Ophthalmol 2018;7:190–194.

26. Arezu H, Jiun D, Hossein A. Eplerenone as a novel treatment for persistent subretinal fluid following retinal detachment surgery. Am J Ophthalmol Case Rep 2018;10:261–263.