The Opacifying Effects of Carteolol HCl and Benzalkonium Chloride on Porcine Isolated Corneas

Porcine isolated corneas (intact, with the epithelium or endothelium plus Descemet's membrane or both epithelium and endothelium plus Descemet's membrane removed) have been incubated with solutions of carteolol HCl (5 x 10-4 M-5 x 10 2M), or solutions of benzalkonium chloride (0.005%–0.05%), or solutions of carteolol (5 x 10 4M-5 x 10 2M) plus benzalkonium chloride (0.005%). Concentration-dependent opacities developed in corneas with both compounds, but whereas the effect of carteolol seems to involve mainly the endothelium, the effect of benzalkonium seems to involve mainly the epithelium. Possible modes of action of the two compounds are discussed.

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Benzalkonium chloride corneal toxicity post-cataract surgery

Asian Journal of Ophthalmology ◽

10.35119/asjoo.v17i1.620 ◽

2020 ◽

Vol 17 (1) ◽

pp. 56-60

Author(s):

Keith Ong ◽

Leonard Ong

Keyword(s):

Cataract Surgery ◽

Benzalkonium Chloride ◽

Corneal Stroma ◽

Eye Drops ◽

Descemet's Membrane ◽

Corneal Toxicity ◽

Descemet’S Membrane ◽

Free Steroid

Two patients with presumed benzalkonium chloride (BAK) corneal toxicity after routine cataract surgery are presented. Patient 1 had corneal stroma and Descemet’s membrane folds. Patient 2 had moderate superficial punctate epithelial erosions (SPEE). They were on Chlorsig, Maxidex, and Acular eye drops tds postoperatively. The corneas of these two patients improved when BAK was removed or minimized from the postoperative eye drop regimen. Two vials of 1 ml dexamethasone 4mg/ml for injection were added to Chlorsig 10 ml bottle to substitute for Maxidex eye drops. BAK toxicity should be suspected when the cornea is not as clear as expected postoperatively. A practical way to eliminate BAK from postoperative eye drops is described, and would be useful until pharmaceuticals mass-produce BAK-free steroid eye drops economically.

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Effects of Benzalkonium Chloride on Pilocarpine-induced Opacity in Porcine Isolated Corneas

Alternatives to Laboratory Animals ◽

10.1177/026119299302100307 ◽

1993 ◽

Vol 21 (3) ◽

pp. 372-383

Author(s):

Haruyoshi Igarashi ◽

Yasunaga Katsuta ◽

Kayoko Sawa ◽

Yuu Chiba ◽

Michio Kozima ◽

...

Keyword(s):

Benzalkonium Chloride ◽

High Performance ◽

Physiological Saline ◽

Experimental Period ◽

Eye Drops ◽

In Vitro Test ◽

Endothelial Surface ◽

Descemet's Membrane ◽

Descemet’S Membrane

The incubation of isolated porcine corneas (intact, with the epithelium or endothelium plus Descemet's membrane removed, or with both the epithelium and endothelium plus Descemet's membrane removed) with solutions of pilocarpine HCl (5 X 10 4M or 5 x 10-3M) for four hours caused very little increase in opacity when compared with corneas incubated with physiological saline. However, at a higher concentration (5 x 10-2M), the application of pilocarpine to the endothelial surface, or to both the epithelial and endothelial surfaces of intact corneas, caused an obvious increase in opacity. The addition of the preservative benzalkonium chloride (BC; 0.005%) to pilocarpine solutions caused an increase in opacity, but in no circumstances did this appear to be other than an additive effect, since incubation with BC alone had an opacifying effect. This in vitro test confirms that pilocarpine is a safe drug for application as eye-drops. Studies using high performance liquid chromatography showed that BC increased the amount of pilocarpine passing through the cornea from the epithelial to the endothelial surface. A small amount of BC also passed through the cornea over the 4-hour experimental period.

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Cleavage plane after liquid‐bubble preparation of Descemet’s membrane

Acta Ophthalmologica ◽

10.1111/aos.14716 ◽

2020 ◽

Author(s):

Annekatrin Rickmann ◽

Silke Wahl ◽

Alisa Katsen‐Globa ◽

André Schulz ◽

Norbert Pütz ◽

...

Keyword(s):

Cleavage Plane ◽

Descemet's Membrane ◽

Liquid Bubble ◽

Descemet’S Membrane

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Corneal pachymetry by AS-OCT after Descemet’s membrane endothelial keratoplasty

Scientific Reports ◽

10.1038/s41598-021-93186-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Friso G. Heslinga ◽

Ruben T. Lucassen ◽

Myrthe A. van den Berg ◽

Luuk van der Hoek ◽

Josien P. W. Pluim ◽

...

Keyword(s):

Deep Learning ◽

Endothelial Function ◽

Corneal Thickness ◽

Anterior Segment ◽

Anatomical Landmarks ◽

Endothelial Keratoplasty ◽

Descemet’S Membrane Endothelial Keratoplasty ◽

Descemet's Membrane ◽

Descemet’S Membrane ◽

Thickness Measurements

AbstractCorneal thickness (pachymetry) maps can be used to monitor restoration of corneal endothelial function, for example after Descemet’s membrane endothelial keratoplasty (DMEK). Automated delineation of the corneal interfaces in anterior segment optical coherence tomography (AS-OCT) can be challenging for corneas that are irregularly shaped due to pathology, or as a consequence of surgery, leading to incorrect thickness measurements. In this research, deep learning is used to automatically delineate the corneal interfaces and measure corneal thickness with high accuracy in post-DMEK AS-OCT B-scans. Three different deep learning strategies were developed based on 960 B-scans from 50 patients. On an independent test set of 320 B-scans, corneal thickness could be measured with an error of 13.98 to 15.50 μm for the central 9 mm range, which is less than 3% of the average corneal thickness. The accurate thickness measurements were used to construct detailed pachymetry maps. Moreover, follow-up scans could be registered based on anatomical landmarks to obtain differential pachymetry maps. These maps may enable a more comprehensive understanding of the restoration of the endothelial function after DMEK, where thickness often varies throughout different regions of the cornea, and subsequently contribute to a standardized postoperative regime.

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