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Purpose: To examine the ocular changes in accommodation, wavefront aberrations, and dynamic range of focus (DROF) after laser scleral microporation (LSM) for treating presbyopia., Methods: Four presbyopic aged cynomolgus macaques (>13 years; n = 8 eyes) were included. All eyes received LSM with erbium: yttrium-aluminum-garnet laser. Spherical equivalent, true accommodation, pseudo-accommodation, wavefront aberrations, and extended range of focus (EROF), or collectively known as DROF, were evaluated using a ray tracing aberrometer. True accommodation referred to the difference in spherical equivalent between distance and near vision, whereas EROF (sum of true and pseudo-accommodation) was determined by measuring the difference in diopters (D) between near and distance through-focus curves, at 50% threshold of the visual Strehl ratio of optical transfer function., Results: From before to seven months after surgery, there was a significant increase in true accommodation from 0.6 ± 1.0 D before surgery to 5.9 ± 2.8 D at seven months after surgery (P < 0.001). EROF increased significantly from 3.4 ± 1.0 D before surgery to 11.1 ± 4.6 D at seven months after surgery (P < 0.001). Ocular aberrations did not vary significantly between preoperative and various postoperative timepoints in either disaccommodated or accommodated states (P > 0.05). No adverse event such as scleral perforation or hypotony was noted., Conclusions: This non-human primate study demonstrated that LSM serves as a novel therapy for improving accommodation and DROF function biomechanically, with a positive response observed throughout the seven-month postoperative period., Translational Relevance: This proof-of-concept study highlights the potential of LSM as a novel treatment for vision recovery in presbyopic eyes.

Purpose: To investigate the postoperative inflammatory and wound-healing responses after laser scleral microporation for presbyopia., Methods: Thirty porcine eyes were used for the optimization of laser intensities first. Six monkeys (12 eyes) received scleral microporation with an erbium yttrium aluminum garnet (Er:YAG) laser, and half of the eyes received concurrent subconjunctival collagen gel to modulate wound-healing response. The intraocular pressure (IOP) and the laser ablation depth were evaluated. The animals were euthanized at 1, 6, and 9 months postoperatively. The limbal areas and scleras were harvested for histologic analysis and immunofluorescence of markers for inflammation (CD11b and CD45), wound healing (CD90, tenascin-C, fibronectin, and HSP47), wound contraction (α-smooth muscle actin [α-SMA]), vascular response (CD31), nerve injury (GAP43), and limbal stem cells (P63 and telomerase)., Results: In the nonhuman primate study, there was a significant reduction in IOP after the procedure. Overall, the ablation depth was 76.6% to 81.2% at 1 month and slightly decreased to 71.5% to 72.7% at 9 months. Coagulative necrosis around the micropores, as well as expression of CD11b, CD45, tenascin, fibronectin, HSP47, and GAP43, was distinct at 1 month but subsided with time. Collagen gel treatment significantly suppressed the upregulation of CD11b, CD45, fibronectin, and tenascin-C. The expression of CD90, α-SMA, and CD31 was minimal in all eyes., Conclusions: The study demonstrated the course of inflammatory and wound-healing responses following laser scleral microporation. The tissue responses were small and self-limited, resolved with time, and were suppressed by concurrent collagen treatment. It provides a useful understanding of this new procedure., Translational Relevance: The results would be helpful in the laser parameter modification to improve the long-term treatment stability., Competing Interests: Disclosure: Y.-C. Liu, None; B. Hall, None; N.C. Lwin, None; E.P.W. Teo, None; G.H.F. Yam, None; A. Hipsley, VisioLite Gen II (P); J.S. Mehta, None, (Copyright 2020 The Authors.)

Purpose: To compare the postoperative higher-order-aberrations (HOAs) after hyperopic small incision lenticule extraction (SMILE), hyperopic laser-assisted in situ keratomileusis ( LASIK), and lenticule implantation for correction of hyperopia., Methods: Eighteen monkeys were divided to six groups: +2.00 D and +4.00 D hyperopic SMILE, +2.00 D and +4.00 D hyperopic LASIK ( n = 6 eyes for each), and lenticule implantation with a -2.00 D and -4.00 D lenticule ( n = 3 eyes for each). The corneal HOAs were evaluated preoperatively and 3-month postoperatively., Results: At 3-month postoperatively, the spherical aberrations significantly increased toward negative direction in all +4.00 D groups (all P < 0.05). There was a significant change toward more negative values in the third-order vertical coma in the SMILE +4.00 D and LASIK +4.00 D groups ( P = 0.026 and P = 0.036, respectively). There were also significant changes in the third-order horizontal trefoil ( P = 0.034) and oblique secondary astigmatism ( P = 0.012) in the LASIK +4.00 D group. In the eyes that underwent +4.00 D lenticule implantation, the fourth-order horizontal quatrefoil significantly increased ( P = 0.029). In low hyperopia correction (+2.00 D), treatment with lenticule implantation tended to have less changes in HOAs, compared to the other two groups., Conclusions: In hyperopic SMILE, hyperopic LASIK or lenticule implantation surgery, significant induction of third- and fourth-order HOAs were seen in moderate hyperopia correction but not in low hyperopia correction. In low hyperopia treatment, lenticule implantation might offer a favorable trend in the aspect of HOAs., Translational Relevance: The results provided the knowledge of surgically induced HOAs and understanding of the effects of surgery in different types of hyperopic correction.

Purpose: To investigate the repeatability and reproducibility of the Visante Omni topography in obtaining topography measurements of rabbit corneas and to develop a post-surgical model of corneal ectasia., Methods: Eight rabbits were used to study the repeatability and reproducibility by assessing the intra- and interobserver bias and limits of agreement. Another nine rabbits underwent different diopters (D) of laser in situ keratosmileusis (LASIK) were used for the development of ectasia model. All eyes were examined with the Visante Omni, and corneal ultrastructure were evaluated with transmission electron microscopy (TEM)., Results: There was no significant intra- or interobserver difference for mean steep and flat keratometry (K) values of simulated K, anterior, and posterior elevation measurements. Eyes underwent -5 D LASIK had a significant increase in mean amplitude of astigmatism and posterior surface elevation with time ( P for trend < 0.05). At 2 and 3 months, the -5 D LASIK group had significant greater mean amplitude of astigmatism ( P = 0.036; P = 0.027) and posterior surface elevation (both P < 0.005) compared with control group. On TEM, the mean collagen fibril diameter and interfibril distance in the -5 D LASIK eyes were significantly greater than in controls at 3 months ( P = 0.018; P < 0.001)., Conclusions: The Visante Omni provided imaging of the rabbit cornea with good repeatability and reproducibility. Application of -5 D LASIK treatment produced a rabbit model of corneal ectasia that was gradual in development and simulated the human condition., Translational Relevance: The results provide the foundations for the future evaluation of novel treatment modalities for post-surgical ectasia and keratoconus.