In Situ Collagen Gel Mold as an Aid in Excimer Laser Superficial Keratectomy

Englanoff, Joseph S; Kolahdouz-Isfahani, Amir H; Moreira, Hamílton; Cheung, David T.; Nimni, Marcel E.; Trokel, Stephen L.; McDonnell, Peter J.

doi:10.1016/s0161-6420(92)31822-6

Cited by 20 publications

(5 citation statements)

References 11 publications

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“…This will reduce the depth of treatment. The liquid often has a faster ablation rate than the epithelium and needs to be refilled several times while the epithelium is removed in steps (Fitzsimmons & Fagerholm; Fasano et al 1991; Kornmehl et al 1991; Englanoff et al 1992; Stevens et al 1994, 1999; Alio et al 2001).…”

Section: Surgical Techniquementioning

confidence: 99%

Phototherapeutic keratectomy: 12 years of experience

Fagerholm

2003

Acta Ophthalmologica Scandinavica

124

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. Background: Phototherapeutic keratectomy (PTK) has been employed as a surgical tool to treat corneal disease for more than 10 years. The laser has made it possible to remove superficial corneal opacities and thereby restore vision. The 193 nm ultraviolet light separates molecules and splits molecules in biological tissue, thereby ablating it. About 0.25 µm of tissue is ablated by each pulse. The development of the excimer laser technique has been fast. It has principally focused on refractive surgery but has also benefited PTK. Corneal dystrophies: The ability to delay or postpone corneal grafting in superficial corneal dystrophies represents a very important achievement. Map‐dot‐fingerprint dystrophy or basal membrane dystrophy is a common indication for PTK. Other dystrophies such as Meesman's, Reis‐Bückler's, Thiel‐Benke's, granular, macular, lattice and Schnyder's can be treated, although with differing degrees of success and varying rates of recurrence. Subepithelial scarring in Fuchs' dystrophy has been ablated. Other trials have involved the removal of substantial parts of the stroma in order to reduce the load on the endothelium. Recurrent dystrophic changes can likewise be removed from corneal grafts and thus prevent the need for regrafting. Recurrent erosions: Laser treatment has made it possible to manage wound‐healing problems better after recurrent erosions. Recurrent erosions are the most common indications for PTK: several studies show good and persistent effects with this type of treatment. Persistent epithelial defects of various origins, among them corneal ulcers resulting from allergic disease, can likewise be treated. Scar tissue: Scars after surgery such as pterygeum excision can be removed. Smooth muscle actin containing fibroblasts in old scars should be given special consideration in PTK. Excimer laser surgery can be successfully combined with conventional surgery to remove excessive scar tissue, Salzmann's nodules and very flaky and coarse band keratopathy. Irregular corneal surfaces following ulcers and injuries pose problems that have so far proved difficult to overcome. Thinning is often seen after bacterial corneal ulcers or after herpes simplex keratitis. A rough or uneven surface can be made smoother by using modulators during treatment by casting a new surface under a hard contact lens (PALM technique), a surface that is then projected into the stroma by laser ablation. Modern techniques linking the excimer laser with computerized corneal topography and wavefront analysis promise to further improve the smoothing capacities of lasers and to increase the quality of optical results. Complications: The most feared complication of PTK is the postoperative infection. These are rare. Haze is usually not prominent but scar tissue formation of a more persistent type has been noted after laser surgery in eyes with pre‐existing surgical scars. Keratectasia has been described after PTK. Failure due to deep opacities or a surface that is too uneven is a more common frustration. T...

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Section: Surgical Techniquementioning

confidence: 99%

Phototherapeutic keratectomy: 12 years of experience

Fagerholm

2003

Acta Ophthalmologica Scandinavica

124

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“…Their applicability as masking agents for corneal photoablation was examined in experimental models of animal and cadaver eyes (Scott et al: Collagen modulator fluids for use during photoablation keratectomy: ARVO 1992, Margaritis et al Properties of a new two component gel material as an aid in PRK corneal remodeling: ARVO 1994) [11-13] as well as in limited clinical trials of partially sighted eyes (Pallikaris et al: Photoablated lenticular modulator PALM technique: A report of ten cases: ARVO 1998) [14,15]. …”

Section: Introductionmentioning

confidence: 99%

The PALM Technique: histological findings of masked phototherapeutic keratectomy on rabbit corneas

et al. 2003

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“…T h e interactions of UV laser radiation with organic polymers have been studied extensively for their potential applications in technology and medicine [1][2][3][4][5][6][7][8][9][10][11][12]. Technological applications include photolithography, a process widely used in semiconductor processing to pattern silicon, oxide, or metal surfaces by a procedure analogous to photography [2,4], and medical applications include its use in cardiovascular and ophthalmologic surgeries [5][6][7][8][9][10][11][12]. Although physical aspects of laser ablation are relatively well understood [3,4], direct chemical analysis of the ablation products is still a challenging task that needs to be explored [4].…”

mentioning

confidence: 99%

“…Thus, the ArF excimer laser has been used extensively in corneal surgeries such as phototherapeutic or photorefractive keratectomy for its ability to precisely remove a predetermined amount of corneal tissue through a photochemical laser-tissue interaction [6][7][8][9]. More recent studies have shown that use of an appropriate masking polymeric fluid in excimer laser surgeries can result in improved smoothness of the corneal surface in these surgical procedures and thus there has been an effort to develop new polymer masks for this purpose [11,12].…”

mentioning

confidence: 99%

Direct chemical analysis of uv laser ablation products of organic polymers by using selective ion monitoring mode in gas chromatography/mass spectrometry

Choi

Lee

Fountain

et al. 1994

J. Am. Soc. Mass Spectrom.

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Trace quantities of laser ablated organic polymers were analyzed by using commercial capillary column gas chromatography/mass spectrometry; the instrument was modified so that the iaser ablation products could be introduced into the capillary column directly and the constituents of each peak in the chromatogram were identified by using a mass spectrometer. The present study takes advantage of the selective ion monitoring mode for significantly improving the sensitivity of the mass spectrometer as a detector, which is critical in anatyzing the trace quantities and confirming the presence or absence of the species of interest in laser ablated polymers. The initial composition of the laser ablated polymers was obtained by using an electron impact reflectron time-of-flight mass spectrometer and the possible structure of the fragments observed in the spectra was proposed based on the structure of the polymers.

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In Situ Collagen Gel Mold as an Aid in Excimer Laser Superficial Keratectomy

Cited by 20 publications

References 11 publications

Phototherapeutic keratectomy: 12 years of experience

Phototherapeutic keratectomy: 12 years of experience

The PALM Technique: histological findings of masked phototherapeutic keratectomy on rabbit corneas

Direct chemical analysis of uv laser ablation products of organic polymers by using selective ion monitoring mode in gas chromatography/mass spectrometry

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