Corneal Wound Healing in Monkeys After Repeated Excimer Laser Photorefractive Keratectomy

Hanna, Khalil

doi:10.1001/archopht.1992.01080210104035

Cited by 143 publications

(59 citation statements)

References 10 publications

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“…[3][4][5][6] In addition, the healing process in vivo involves interactions among various cell types within the cornea. Physical stimulation by excimer laser energy may also trigger an inflammatory response.…”

Section: Discussionmentioning

confidence: 99%

Inflammatory Response in the Early Stages of Wound Healing After Excimer Laser Keratectomy

O’Brien¹

1998

Arch Ophthalmol

108

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To evaluate the inflammatory response and its potential role in the early stages of corneal wound healing after excimer laser keratectomy.Materials and Methods: Lewis rats underwent excimer keratectomy using a 193-nm excimer laser. The central corneas were ablated in 3 depths: group A, epithelium; group B, superficial stroma; or group C, deep stroma. Eyes were harvested 1, 12, 24, and 36 hours, and 1 week after the rats were killed. Immunohistochemistry was used to test frozen sections with monoclonal antibodies of various inflammatory cellular markers. Results:Reepithelialization was observed at 12 hours in group A, and at 24 hours in groups B and C. Regenerated epithelium covered the denuded corneal surface in groups B and C after 1 week. The expression of major histocompatibility complex II antigen was detected in infiltrating cells, corneal epithelial cells, and endothelial cells 1 hour after surgery. Only a few macrophages and Langerhans cells were in the limbus at baseline. Macrophages migrated from the limbus to the corneal ablation zone and increased 2-fold after 36 hours in all 3 groups compared with baseline. Occasional lymphocytic infiltration was identified after 25 to 36 hours. Conclusion:Macrophages play an active role in the wound healing after laser keratectomy and may contribute to transient corneal haze.

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Section: Discussionmentioning

confidence: 99%

Inflammatory Response in the Early Stages of Wound Healing After Excimer Laser Keratectomy

O’Brien¹

1998

Arch Ophthalmol

108

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“…It is therefore possible that the corneas in excimer ablated and contralateral eyes still have different morphology regarding the ultrastructure of the basement membrane and adhesions complexes at the time points investigated. In any case, previous studies have shown that corneas treated with excimer laser heal without a tendency for recurrent abrasions (Hanna et al 1990, Ehlers & Hjortdahl 1992 ) indicating a functional epithelial-stromal adhesion complex. In fact, recurrent corneal erosion has been found to be an indication for excimer laser ablation ( Dausch et al 1993, Hersh et al 1993, Ohrman et al 1994, Poirier et al1994, John et al 1994.…”

Section: Discussionmentioning

confidence: 73%

“…Marshall (1986) found that the basal cells of rabbit cornea had begun to re-establish a basement membrane 2 weeks after excimer laser treatment. Hanna et al (1990), however, demonstrated that an abnormal basement membrane was still present 18 months after excimer laser treatment of the monkey cornea. It is therefore possible that the corneas in excimer ablated and contralateral eyes still have different morphology regarding the ultrastructure of the basement membrane and adhesions complexes at the time points investigated.…”

Section: Discussionmentioning

confidence: 94%

Regeneration of epithelial defects in corneas previously treated with excimer laser, A study of cell kinetics in the rat corneal epithelium

Sandvig

Kravik

Blika

1998

Acta Ophthalmologica Scandinavica

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ABSTRACT.Purpose: The present study was to investigate, using cell kinetic methods, whether previous excimer laser treatment affected healing of later corneal epithelial erosions. Methods: The right eyes of rats underwent central excimer corneal stromalepithelial ablations (ArF 193 nm, 228 pulses, diameter 3,5 mm, 17,3 mJ per pulse, depth about one third of corneal thickness) and were allowed to heal for 15 weeks. Then central circular epithelial abrasions (diameter 3 mm), using NHeptanol and mechanical debridement, were made on both corneas. The rats were killed 1,2,4 and 6 days after the last treatment. The central stromal thickness, the epithelial cell density, the labelling index (LI) and the mitotic rate (MR) of the peripheral, the midperipheral and the central areas of the corneal epithelium were calculated for each timepoint. Results: The central stromal thickness increased equally in the two groups the first day after making the erosion, normalising in both groups during the following days. The corneal epithelium was restored at the same rate in both groups. The cell number per microscopic visual field, the LI and the MR were very similar for the two groups at all timepoints. Conclusion: Previous excimer laser treatment does not seem to interfere with healing of later epithelial erosions, when studied with cell kinetic methods.

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“…19 This result can be explained by the effect of the prophylactic use of 0.02% mitomycin C, and the surface smoothing technique, which are known to be effective for the prevention of corneal-haze after PRK in highly-myopic patients. 15,20,21 According to clinical corneal-haze classification of Hanna et al, 13 corneal-haze grade 1.0 is mild, faint reticular haze which can be only seen by broad-tangential illumination, and vision is not affected graded 0 to 1.0. Thus, all patients in our study obtained UDVA of 20/20 or better.…”

Section: Discussionmentioning

confidence: 99%

“…All patients underwent a preoperative-ophthalmic examination, including uncorrected-distance visual acuity (UDVA), corrected distance visual acuity (CDVA), slit-lamp biomicroscopy including corneal-haze grading, tonometry, fundus examination, ultrasound pachymetry, pupillometry, corneal topography, and wavefront aberrometry. Corneal-haze levels were determined using a slit lamp, according to the method of Hanna et al 13 Without moving the patients or the instrument, Figure 1 Flow chart of the study. pupillometry, corneal topography, and wavefront aberrometry were measured on the same optical axis using an OPD-Scan III device (Nidek Co. Ltd.), with the pupils dilated to at least 6 mm.…”

Section: Methodsmentioning

confidence: 99%

Clinical outcomes between optical path difference custom aspheric treatment and optimized prolate ablation photorefractive keratectomy in myopia exceeding 8 diopters

Choi¹,

Park

Lee

2014

Eye

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Purpose Comparison of visual acuity, refractive, and wavefront outcomes associated with optimized prolate ablation (OPA) and optical path difference custom aspheric treatment (OPDCAT) algorithms for correction of myopia exceeding 8 diopters (D). Patients and Methods Patients were randomly assigned to have photorefractive keratectomy (PRK) with OPA (n ¼ 32) or OPDCAT (n ¼ 21) algorithms. Visual acuity, manifest refraction, ocular and corneal higher-order aberrations, corneal asphericity, modulated-transfer function, and pointspread function were compared 1, 3, and 6 months postoperatively. Results Mean manifest-refraction spherical equivalents at 6 months were À 0.24 D in both groups. All patients in both groups had an uncorrected-distance visual acuity of 20/20 or better. Predictability ( ± 1 D from intended refraction) at 6 months was 94% in the OPA group, and in the OPDCAT group it was 86%. The OPA group had less induced corneal and ocular spherical aberrations (SAs) than the OPDCAT group. Postoperative corneal asphericity change was lowest in the OPA group. Both the groups exhibited significantlyimproved AreaRatio-Total value and insignificantly deteriorated AreaRatio-HO value throughout the postoperative period. The OPA group had significantly-higher AreaRatio-Total compared with OPDCAT group at both 1 and 6 months after the operation. Six months after surgery, the Strehl ratio had decreased in both groups, and there was no significant difference between the groups. Conclusion The OPA algorithms yielded higher-objective visual quality and predictability, induced less corneal and ocular SAs, and preserved more preoperativecorneal asphericity than the OPDCAT algorithms.

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Corneal Wound Healing in Monkeys After Repeated Excimer Laser Photorefractive Keratectomy

Cited by 143 publications

References 10 publications

Inflammatory Response in the Early Stages of Wound Healing After Excimer Laser Keratectomy

Inflammatory Response in the Early Stages of Wound Healing After Excimer Laser Keratectomy

Regeneration of epithelial defects in corneas previously treated with excimer laser, A study of cell kinetics in the rat corneal epithelium

Clinical outcomes between optical path difference custom aspheric treatment and optimized prolate ablation photorefractive keratectomy in myopia exceeding 8 diopters

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