Laser Trabeculoplasty and Aqueous Dynamics

For the past four decades, laser trabeculoplasty has been a staple in the treatment armamentarium against glaucoma. Although the exact mechanism of laser trabeculoplasty has not been fully elucidated, its clinical utility in lowering intraocular pressure has been well established. Aqueous dynamic studies uniformly reveal an increase in aqueous outflow facility at the trabecular meshwork. Accumulating evidence suggests that the mechanism is the result of complex cellular and biochemical processes. Histopathological studies of the trabecular meshwork tissue after argon laser suggest an additional mechanical role. The traditional treatment algorithm for glaucoma placed laser trabeculoplasty as an intermediary between medical therapy and incisional surgery. However, because of the safety profile of selective laser trabeculoplasty, recent studies have challenged this treatment paradigm. One such study was a multicenter trial headed by our department that compared laser trabeculoplasty and medical therapy as initial treatment for glaucoma. We showed a similar efficacy between the two modalities, reinforcing the possibility of using laser as the initial treatment in the right clinical setting

Efficacy of wavefront-guided photorefractive keratectomy with iris registration for management of moderate to high astigmatism by advanced personalized treatment nomogram

Purpose: To evaluate the efficacy of photorefractive keratectomy (PRK) using the advanced personalized treatment (APT) nomogram for correction of moderate to high astigmatism. Methods: This prospective interventional case series included 60 consecutive eyes of 30 patients undergoing wavefront-guided PRK (Zyoptix 217 Z100 excimer laser, Bausch & Lomb, Munich, Germany) using the APT nomogram and iris registration for myopic astigmatism. Mitomycin-C was applied intraoperatively in all eyes. Ophthalmic examination was performed preoperatively and 1, 3 and 6 months postoperatively. Results: Preoperatively, mean sphere was -1.68 ± 2.08 diopters (D), mean refractive astigmatism was -3.04 ± 1.05 D and mean spherical equivalent (SE) was -3.12 ± 1.77 D. Six months postoperatively, mean sphere was + 0.60 ± 0.64 D (P < 0.005), mean cylinder was -0.43 ± 0.46 D (P < 0.005) and mean SE was + 0.28 ± 0.48 D (P < 0.005). Hyperopic overcorrection (≥ +1.0 D) occurred in 3 (5%) eyes. Postoperatively, root mean square (RMS) of higher order aberrations (HOAs) was significantly increased (P = 0.041). RMS of spherical aberration (Z [4, 0]) showed no significant change after surgery (P = 0.972). Conclusion: Considering the acceptable residual refractive error, low rate of hyperopic overcorrection, acceptable uncorrected visual acuity, and low risk of postoperative corneal haze, PRK using the APT nomogram with iris registration and mitomycin-C use is a safe and effective modality for treatment of moderate to high astigmatism

Evolution of cyclophotocoagulation

Cyclodestructive techniques have been a treatment option for refractory glaucoma since its first use in the 1930s. Over the past nine decades, cyclodestruction has advanced from the initial cyclodiathermy to micropulse transscleral cyclophotocoagulation (MP-TSCPC) which is the current treatment available. Complications associated with cyclodestruction including pain, hyphema, vision loss, hypotony and phthisis have led ophthalmologists to shy away from these techniques when other glaucoma treatment options are available. Recent studies have shown encouraging clinical results with fewer complications following cyclophotocoagulation, contributing greatly to the current increase in the use of cyclophotocoagulation as primary treatment for glaucoma. We performed our literature search on Google Scholar Database, Pubmed, Web of Sciences and Cochrane Library databases published prior to September 2017 using keywords relevant to cyclodestruction, cyclophotocoagulation and treatment of refractory glaucoma

Visual field changes in professional wind versus non-wind musical instrument players in the Philadelphia orchestra

Purpose: We compare the prevalence of glaucoma in professional wind versus non-wind instrument players in the Philadelphia Orchestra. Visual field changes in individuals with glaucoma and glaucoma suspects were evaluated, and the results were correlated with cumulative practice time. Methods: In this cross-sectional, observational study, fifty-one Philadelphia Orchestra musicians were enrolled and categorized as wind or non-wind instrument players. All study participants underwent screening fundus photography. Participants with optic discs suspicious for glaucoma underwent further evaluation, including standard automated visual field perimetry and a comprehensive eye examination by a glaucoma specialist. Results: Of the 51 musicians enrolled, 9 of the 21 wind instrument players (43%) and 8 of the 30 non-wind instrument players (27%) were suspected of developing glaucoma in at least one eye (P = 0.25), with examinations performed on 12 of the 17 returning musicians (71%) for further confirmation. Wind instrument players exhibited significantly higher Octopus visual field mean defect scores (1.08 ± 1.5 dB) than non-wind instrument players (−0.43 ± 0.7 dB; P < 0.001). There was a significant association between cumulative hours playing wind instruments and visual field mean defect (P < 0.001). Conclusion: Among members of the Philadelphia Orchestra, the difference in prevalence of glaucoma suspicious optic discs between wind and non-wind instrument players was not significant. The clinical significance of the greater visual field mean defect found in wind instrument players, and the association between the degree of visual field mean defect and the cumulative practice-time of playing wind instruments, needs further investigation