Intrastromal Injection of Hyaluronidase Alters the Structural and Biomechanical Properties of the Corneal Stroma

We report the self-limited nature of corneal opacification after accidental injection of Healon5 into the corneal stroma. A 52-year-old male with a new diagnosis of severe stage, primary open-angle glaucoma underwent successful trabeculectomy OS, which was complicated by ocular hypotony and shallow anterior chamber (AC) on postoperative day 1. Healon5, a hyaluronic acid-containing viscoelastic device, was accidentally introduced into the corneal stroma during attempted injection into the AC. The cornea hydrodissected and opacified, leading to precipitous loss of best-corrected visual acuity (BCVA). The corneal opacification spontaneously resolved over a 7-month period without specific intervention. During this period, the patient also underwent cataract extraction with posterior chamber intraocular lens placement and YAG capsulotomy, after which his BCVA returned to approximately baseline. Though intrastromal injection of sodium hyaluronate-containing material has been reported elsewhere, this complication with Healon5 use specifically has yet to be described in the literature and may occur in any procedure involving Healon5 in the AC. This case report is important, since the precipitous loss of BCVA can be alarming to the ophthalmologist and the patient. The affected patient may be counseled that the opacification should improve with time.

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Depth Dependent In-Plane Shear Properties of the Corneal Stroma

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19302 ◽

2010 ◽

Author(s):

Steven Petsche ◽

Peter Pinsky ◽

Dimitri Chernyak ◽

Jaime Martiz

Keyword(s):

Shear Modulus ◽

Patient Outcomes ◽

Surgical Procedures ◽

Refractive Surgery ◽

Corneal Stroma ◽

Shear Stiffness ◽

Biomechanical Properties ◽

Human Cornea ◽

Plane Shear ◽

Biomechanical Response

The popularity of refractive surgery to correct the vision of individuals with hyperopia or myopia is increasing. These procedures alter the tissue of the human cornea to cause a change in curvature (refractive power) of the cornea. Radial keratotomy, photorefractive keratectomy, LASIK, and LASEK are all types of refractive surgery. The outcomes of refractive surgical procedures must depend significantly on the biomechanical response of the tissue and therefore on the biomechanical properties of the cornea, or more specifically the corneal stroma which makes up 90% of the tissue. The missing link between computer models of these procedures and predicting patient outcomes is the biomechanical properties of the tissue, including shear modulus. This study aims to characterize the in-plane shear modulus of the corneal stroma through the depth by mechanical testing. Scant data, if any, exists about the shear stiffness and no data includes depth dependence. The stroma consists of sheets of collagenous lamellae in which fibrils are maintained at uniform spacing by glycoaminoglycan molecules. Studies have shown increased interweaving of the lamellae in the anterior third of the stroma compared to the central and posterior thirds [1]. Figure 1 shows the distinct interweaving in the anterior third [2]. It is hypothesized that more interweaving lamellae increases the in-plane shear stiffness. The shear modulus of the full cornea, as well as individual thirds, is examined in this study.

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Efficacy of Voriconazole Corneal Intrastromal Injection for the Treatment of Fungal Keratitis

Journal of Ophthalmology ◽

10.1155/2021/5597003 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Chenshuang Li ◽

Kunpeng Pang ◽

Liqun Du ◽

Xinyi Wu

Keyword(s):

Visual Acuity ◽

Corneal Stroma ◽

Fungal Keratitis ◽

Antifungal Treatment ◽

Treatment Modalities ◽

Control Group ◽

Significant Difference ◽

The Difference ◽

Contralateral Eye ◽

Intrastromal Injection

Purpose. To evaluate efficacy and safety of novel tricyclic corneal stroma injection (TCSI) voriconazole for the treatment of fungal keratitis. Methods. This retrospective cohort study included data of 57 patients (57 eyes) with fungal keratitis. The TCSI group consisted of 27 patients (27 eyes) who were injected voriconazole once via TCSI procedure within one week after enrollment, in addition to conventional antifungal treatment. The control group consisted of 30 patients (30 eyes) who were treated using conventional antifungal treatment modalities. The outcome measures consist of the 3-week and 3-month best-corrected visual acuity (BCVA) values and size of infiltrate or scar, time to re-epithelialization, corneal perforation rate and/or therapeutic penetrating keratoplasty (TPK) requirement, the preoperative and post-TCSI corneal endothelial cell density (ECD), and the intraocular pressure (IOP) of the treated eye and the respective contralateral eye. Results. There were no significant differences in the baseline demographic and clinical characteristics between the two groups. 3 weeks and 3 months after enrollment, the TCSI group exhibited an increase in visual acuity ( P < 0.05 ), and there was no significant difference in the size of infiltrate or scar between two groups ( P > 0.05 ). Time to re-epithelialization was shorter in the TCSI group than in the control group ( P < 0.05 ). There was no statistically significant difference between corneal ECD on the day before and 7 days after TCSI and the IOP of treated and contralateral healthy eyes on the day before and 1 day, 3 days, 7 days, and 1 month after TCSI ( P > 0.05 ). The difference in the risk of perforation and/or TPK requirement was not statistically significant between two groups ( P > 0.05 ). Conclusion. Localized injection of voriconazole using TCSI may be a minimally invasive, safe, and effective adjuvant treatment modality for fungal keratitis.

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