Coelho et al.1 have described a novel approach to rescuing a peripheral capsulorrhexis tear out during cataract surgery. A discontinuous curvilinear capsulorrhexis can compromise the integrity of the capsular bag, with serious consequences for the rest of the procedure. This technique is a useful addition to the surgical repertoire, but we believe it should be used with caution. This procedure is particularly aggressive, with associated anterior capsule stretch and potential zonular weakening and damage. There is a known relationship between the stretching capacity of the anterior capsule and the zonular fibers,2 so we would recommend using this new technique as an absolute last resort and totally avoiding it in cases in which the zonule may be compromised, such as denser cataracts of elderly patients, pseudoexfoliation cases, or history of trauma.3,4 The demographic and clinical information of the 50 cataract cases performed by Coelho et al.1 are unknown so it is impossible to know whether the technique was used in any patient with the above-mentioned characteristics. Additionally, the authors mention and show in their video that they could not perform Little et al.'s technique5 or the other rescue techniques because of the poor visualization of the capsule root, which is a problem that could be dealt with using iris hooks. The authors also suggest that trainee or inexperienced surgeons may not have sufficient skills to carry out this procedure; however, this cohort of surgeons are perhaps the ones who have a higher likelihood of capsulorrhexis tear outs. Again, the authors do not provide information regarding how many different surgeons and of what level this technique was performed by. Finally, avoiding peripheral tear out with the use of a heavier cohesive ophthalmic viscosurgical device (OVD) such as Healon GV or a viscoadaptive OVD such as Healon V and greater control is the ultimate goal with efforts directed at prevention of these difficult situations.6
We read with interest the report by Girolamo et al. (1) using an extended wear soft bandage contact lens (SBCL) to expand autologous corneal epithelial progenitor cells for subsequent transfer onto corneas with kerato-limbal stem-cell deficiency (LSCD). The use of the SBCL alone has been shown to contribute to stabilization of the corneal epithelium in kerato-LSCD, specifically rendering a corneal transplant surface intact in an aniridic patient with recurrent epithelial breakdown (2). The authors of this study fail to exclude the role that the bandage contact lens alone, in the absence of autologous epithelial progenitor cells, may have in contributing to healing of the corneal epithelium. A simple solution would have been the use of a crossover control by placing a SBCL without progenitor cells for 1 week on the cornea, before switching it with a SBCL containing these cells. We previously described the effect of tissue-cultured human amniotic epithelial cells (AECs) in restoring the ocular surface in three patients with persistent corneal epithelial defects secondary to LSCD refractory to medical therapy (3). Two cases were secondary to neurotrophic keratopathy, whereas one case was attributable to longstanding alkali injury. These AECs were transplanted onto the cornea using a collagen shield seeded with AECs supported by a soft contact lens. The collagen shields dissolved by 72 hr, and the contact lenses were removed after this time. This cycle was repeated every week until healing was achieved. As a crossover control, collagen shields without AECs were placed in the same eye 1 week before placing collagen shields containing AECs, supported by a SBCL for 72 hr. No change in persistent corneal epithelial defect size was observed in those control eyes receiving collagen shields without AECs. Complete resolution of the PED was seen after two cycles of AEC-seeded collagen shield in one case, and four cycles in two cases, from 7 to 12 weeks after treatment in all patients. No loss of visual acuity was seen, and the clinical improvement was maintained in all cases, with a mean follow-up of 6.3 months. In light of the methodology described earlier, we would urge the authors of this study to use a crossover control for future patients. Dipak N. Parmar Department of Ophthalmology Whipps Cross University Hospital London, United Kingdom Hassan Alizadeh Department of Ophthalmology University of Texas Southwestern Medical Center Dallas, Texas Shady Awwad Department of Ophthalmology American University of Beirut Lebanon Richard W. Bowman H. Dwight Cavanagh James P. McCulley Department of Ophthalmology University of Texas Southwestern Medical Center Dallas, Texas
This paper aims to review the recent literature describing Acanthamoeba keratitis and outline current thoughts on pathogenesis, diagnosis, and treatment as well as currently emerging diagnostic and treatment modalities.
PARMAR, DIPAK N. BSc (Horns), FRCOPHTH; STANGA, PAULO E. MD; RECK, ANNE C. MD; VINGERLING, JOHANNES R. MD; SULLIVAN, PAUL MD, FRCOPHTH Author Information
Background. An 85-year-old man developed faint crystallike white precipitates in the mid peripheral stroma of his left cornea 3 weeks after undergoing penetrating keratoplasty. The patient had been initially treated with 1% prednisolone acetate ophthalmic suspension and 0.3% gatifloxacin eyedrops to his left eye from the first day postoperatively. Three weeks later, the precipitates were more numerous, larger, and diffuse in distribution. Gatifloxacin was discontinued and substituted with a neomycin–polymixin B–dexamethasone ophthalmic ointment. Methods. A detailed history, physical examination, laboratory workup, and tandem scanning confocal microscopy were performed. Results. Tandem scanning corneal confocal microscopy confirmed the presence of crystals in the cornea. Conclusions. Gatifloxacin, a fourth-generation fluoroquinolone, can cause intrastromal macroscopic crystalline deposits through a compromised corneal epithelium, similar to what has been described for ciprofloxacin, a second-generation fluoroquinolone.
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