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Laser Scleral Microporation Proposed As Accommodation Restoration

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Laser Scleral Microporation Proposed As Accommodation Restoration 34 JUNE 1, 2018 :: Ophthalmology Times ) Special Report SURGICAL & CLINICAL SOLUTIONS FOR PRESBYOPIA Laser scleral microporation proposed as accommodation restoration therapy Visual axis untouched, meaning patients can benef t from future corneal, cataract surgeries By Laird Harrison; Reviewed by Sunil Shah, MBBS, FRCOphth, FRCS, FBCLA, and AnnMarie Hipsley, DPT, PhD LASER SCLERAL microporation appears Current treatments com- promising as a treatment for presbyopia in em- pensate for the lost accom- metropic subjects, according to Sunil Shah, modation rather than restor- MBBS, FRCOphth, FRCS, FBCLA. ing it. Whether induced by Unlike most treatments for presbyopia, the manipulating multifocality, technique restores some natural ability to ac- monovision, or depth of focus commodate along with some extended depth by using laser refractive proce- of focus (EDOF) by increasing compliance in dures or created with contact the sclera, said Dr. Shah, professor, Aston Uni- lenses, all of these procedures versity, Birmingham, UK. may decrease binocularity, The procedure—in which a laser creates tiny stereopsis, and uncorrected micropores in the sclera—is an advanced iter- distance visual acuity. ation of a technique pioneered a decade ago, Although monovision is the laser anterior ciliary excision (LaserACE). In most popular treatment alter- a preliminary trial of the new approach, sub- native to reading glasses, most jects gained a median 4.5 lines of near and people with presbyopia can- intermediate visual acuity. not tolerate it, Dr. Shah said. The technique is based on new understand- Likewise, corneal presby- ing of the etiology of presbyopia and the bio- opic correction—an attempt (FIGURE 1) Schematic representation of the laser scleral microporation mechanical mechanisms involved in accom- to create a bifocal or multifo- procedure over the f ve critical anatomical zones of physiological and modation. While most attention in the past cal cornea—can also result biomechanical importance. has focused on changes in the lens, recent in loss of binocularity, ste- discoveries have highlighted the role of other reopsis, or distance vision. structures, including the sclera and choroid. In laser scleral microporation, an Er:Yag laser All ocular tissues stiffen or lose elasticity as uses 225-µm spots to create a 5- x 5-mm ma- the eye ages just like many other connective trix of micropores in a variety of densities and tissues in the body. Age-related changes in the number that are 225 µm in diameter in four eye result largely from the steady increase in oblique quadrants of the eye. crosslinks or bonds between polymer chains in According to Dr. Hipsley’s postulate, the cre- the collagen and elastin that form ation of the micropore matrix over the fibrils and microfibrils in the five key critical zones of biome- sclera, Dr. Shah said. chanical and physiological impor- take-home tance improve the compliance of DIVING DEEPER ◗ With laser scleral the sclera in these regions to yield In her published manuscript, “Visio- microporation, a to accommodative forces from the Dynamics Theory: A Biomechanical laser creates tiny ciliary muscles and extralenticu- Model for the Aging Ocular Organ” micropores in the lar anatomy, thus restoring the (Jaypee Books, 2003), AnnMarie sclera. In a preliminary efficiency of the accommodation (FIGURE 2) Microporations in four oblique Hipsley, DPT, PhD, described an trial, subjects gained mechanism. quadrants over the f ve critical anatomical zones a median 4.5 lines of age-related progressive “scleroscle- In a trial of 12 patients, mean of physiological and biomechanical importance. rosis” which decreases scleral com- near and intermediate monocular uncorrected visual acu- (Images courtesy of AnnMarie Hipsley, DPT, PhD) pliance in response to forces ap- visual acuity. ities at near (40 cm), intermediate plied during accommodation, thus (60 cm), and distance (4 m) im- reducing accommodative efficiency. proved from +0.65 logMAR, +0.54 logMAR, sual acuities at near (40 cm), intermediate (60 Some researchers have estimated that ex- and +0.20 logMAR, respectively, preopera- cm), and distance (4 m) improved from +0.6 tralenticular structures could account for up tively, to +0.27 logMAR, +0.15 logMAR (p logMAR, +0.47 logMAR, and +0.19 logMAR, to 2 D of accommodation, and the aging of = 0.0087), and +0.11 logMAR, respectively, respectively, preoperatively, to +0.14 logMAR, the structures might result in 1 to 2 D of lost at 1 month postoperatively. +0.08 logMAR, and -0.04 logMAR, respectively, accommodation. Similarly, mean binocular uncorrected vi- Continues on page 35 : Laser scleral JUNE 1, 2018 :: Ophthalmology Times 35 ) Special Report SURGICAL & CLINICAL SOLUTIONS FOR PRESBYOPIA The improvements appear long-lasting. In don’t get a complete loss of effect. We need LASER SCLERAL a study on macaque monkeys, the research- longer-term data with the new system.” ers found cellular infiltration at the margin of The newer system—laser scleral micropo- ( Continued from page 34 ) the micropores at 1 month, Dr. Hipsley noted. ration—is faster and easier because it treats The inflammatory response subsided after four quadrants in 14 seconds each, employ- that. The researchers noted coagulative necro- ing a scanning technology. LaserACE was per- at 1 month postoperatively. No patients expe- sis at the margins of the micropores. formed with a fiberoptic handheld probe and rienced complications that decreased best-cor- “Overtime, the inflammatory response re- performed only 1 spot at a time. rected visual acuity or quality of vision, he said. ceded leaving clear histological evidence, how- An advantage to laser scleral microporation “It’s topical anesthesia, and they barely feel ever, that the healed micropore was not as compared with other presbyopia treatments is anything because you’re only doing a very tiny dense as the surrounding untreated sclera,” that the visual axis remains untouched. This microporation,” Dr. Shah said. “They don’t have Dr. Hipsley said. means patients can benefit from future corneal any problem at all, and very little discomfort Researchers also reported that scleral fibro- or cataract procedures, such as receiving en- afterward either.” blasts migrated and proliferated into the mir- hancements to LASIK or accommodative IOLs, Some evidence suggests decreasing ocular copores. Collagen treatment reduced this re- the researchers noted. Q rigidity may affect the development of glau- sponse in the early period after the procedure. coma and age-related macular degeneration So far, these changes do not appear to cause as well as presbyopia. With the loss of elas- a reversal of the effects of the microporation. ticity, the sclera puts compression and load- The researchers are still collecting longer-term ing stresses on underlying structures, and can data with this version of the procedure. But affect blood flow through the sclera and optic they have followed for over 10 years patients SUNIL SHAH, MBBS, FRCOPHTH, FRCS, FBCLA nerve, according to Dr. Hipsley. who underwent a preceding similar scleral pro- E: [email protected] An earlier iteration of the procedure (Laser- cedure, LaserACE. This article was adapted from Dr. Shah’s presentation at the 2018 meeting of the ACE) has shown a statistically significant re- These patients have continued to enjoy re- American Society of Cataract and Refractive Surgery. He is a consultant to AceVision. duction in IOP from a mean of 13.56 mm Hg at duced presbyopia, Dr. Shah said. baseline to 11.74 mm Hg after 2 years, she said. “The 10-year data we’ve got shows it doesn’t ANNMARIE HIPSLEY, DPT, PHD Investigations of the effects of laser scleral mi- come back,” he said. “There is some progres- E: [email protected] croporation on intraocular pressure are ongoing. sion with age as would be expected, but you Dr. Hipsley is founder and CEO of AceVision. OCULAR SURFACE or out-of-pocket expenditures that might make surgeons look to further refine outcomes and patients hesitant to move forward. It has been ensure patient happiness, the subtle change ( Continued from page 33 ) our experience, however, that patients appreci- to being more proactive about managing the ate knowing how they can maximize outcomes ocular surface perioperatively represents an and improve healing, with the ancillary ben- important step in achieving the goals that pa- while reducing markers of inflammation and efit of tacitly letting them know we will take tients want. Q ocular surface disease index score by 12 weeks.1 steps to ensure they are happy with results. At least two mechanisms have been pro- References posed—the breakdown of omega-3 fatty acids CONCLUSION 1. Epitropoulos AT, Donnenfeld ED, Shah ZA, Holland results in anti-inflammatory molecules and/or Optimizing the ocular surface prior to refrac- EJ, Gross M, Faulkner WJ, Matossian C, Lane SS, the use of omega-3 fatty acids alters the com- tive surgery is not intended to be a panacea. Toyos M, Bucci FA Jr, Perry HD. Effect of oral re- position of meibomian gland secretions such Whether a patient is set to undergo PRK, LASIK, esterified omega-3 nutritional supplementation on that they no longer induce blockade of the or even newer options like SMILE, the proce- dry eyes. Cornea. 2016;35:1185-1191. glands.1 Either mechanism (or both) increases dure will disrupt the corneal nerve plexus. 2. Macsai MS. The role of omega-3 dietary supplementation in blepharitis and meibomian meibomian gland secretions that reduces tear Transient dryness is almost an inevitability, gland dysfunction. Trans Am Ophthalmol Soc. 2 film evaporation. Getting neutraceuticals on and if it is not mentioned prior to surgery, it 2008;106:336–356. board prior to surgery maximizes the poten- becomes more problematic. tial for the tear film to respond to the surgical At the same time, with safe/effective treat- insult and heal properly. ments at surgeons’ disposal, both cost and Additional measures may be added as needed.
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