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Customized epithelial debridement for thin ectatic corneas undergoing corneal cross-linking: epithelial island cross-linking technique.

Mazzotta C, Ramovecchi V - Clin Ophthalmol (2014)

Bottom Line: Thin corneas with a minimum corneal thickness less than 400 μm after epithelial removal represent a contraindication to standard epithelium-off cross-linking (CXL) treatment due to a significant endothelial cell density decrease and potentiality of permanent haze development.However the iatrogenic swelling effect might not be durable throughout the CXL procedure increasing the risk of postoperative complications.According to our clinical and in-vivo micro-morphological results the technique results safe, and efficacious in stabilizing progressive keratoconus and may be considered a valid option in the treatment of thin ectatic corneas alone or in combination with hypoosmolar or dextran-free riboflavin solutions.

View Article: PubMed Central - PubMed

Affiliation: Unità Operativa Complessa di Oculistica, Siena University Hospital, Siena, Italy.

ABSTRACT
Thin corneas with a minimum corneal thickness less than 400 μm after epithelial removal represent a contraindication to standard epithelium-off cross-linking (CXL) treatment due to a significant endothelial cell density decrease and potentiality of permanent haze development. Preoperative swelling of the cornea with hypoosmolar riboflavin solutions broadens the spectrum of CXL indications to thin corneas. However the iatrogenic swelling effect might not be durable throughout the CXL procedure increasing the risk of postoperative complications. The transepithelial CXL technique proposed for thin corneas demonstrated poor clinical results and mid- to long-term keratoconus instability. The epithelial island CXL technique with customized pachymetry-guided epithelial debridement was evaluated by means of in vivo laser scanning confocal microscopy, corneal topography, and clinical examination in a 1-year follow-up, in order to assess if it may be considered an alternative surgical option for keratoconic patients with thin corneas undergoing corneal collagen CXL. According to our clinical and in-vivo micro-morphological results the technique results safe, and efficacious in stabilizing progressive keratoconus and may be considered a valid option in the treatment of thin ectatic corneas alone or in combination with hypoosmolar or dextran-free riboflavin solutions.

No MeSH data available.


Related in: MedlinePlus

Confocal pachymetric scan and topographic keratoconus apex localization.Notes: (A) Confocal scan revealed the typical keratoconus changes of a 391 μm thin cornea: stromal keratocytes (white arrow); Vogt’s dark deep striations (red arrows); and pleomorphic endothelium (green arrow). (B) Altimetry map with polar grid superimposition allowing a precise localization of the keratoconus apex in the classic inferior-temporal dislocation (white arrow, red spot).
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f1-opth-8-1337: Confocal pachymetric scan and topographic keratoconus apex localization.Notes: (A) Confocal scan revealed the typical keratoconus changes of a 391 μm thin cornea: stromal keratocytes (white arrow); Vogt’s dark deep striations (red arrows); and pleomorphic endothelium (green arrow). (B) Altimetry map with polar grid superimposition allowing a precise localization of the keratoconus apex in the classic inferior-temporal dislocation (white arrow, red spot).

Mentions: Ten patients with progressive keratoconus, having an average age of 21 years (range 13–26 years) and thin corneas with an average thinnest point of 384 μm (range 368–391 μm) were enrolled in the treatment protocol. All patients were afflicted with stage III keratoconus according to Krumeich’s staging with clinical and instrumental progression in the last 6 months of observation (increased K average >1 Diopter, optical pachymetry difference >10 μm, uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) worsening of at least of 0.1 decimal equivalent). Patients underwent clinical and instrumental pre-operative evaluation before the procedure and post-operatively at day 3, and 1, 3, 6, and 12 months follow-up, by corneal topography, tomography, Heidelberg retina tomograph (HRT) in vivo laser scanning confocal microscopy, and endothelial cells’ count. Corneal topography performed with the Eye-Top corneal topographer (C.S.O. Srl, Florence. Italy) with a polar grid superimposition and altimetry algorithm allowed a reliable keratoconus apex geometric localization and together with laser scanning confocal microscopic analysis increase the information on corneal microstructure and thickness useful for a correct treatment planning (Figure 1).


Customized epithelial debridement for thin ectatic corneas undergoing corneal cross-linking: epithelial island cross-linking technique.

Mazzotta C, Ramovecchi V - Clin Ophthalmol (2014)

Confocal pachymetric scan and topographic keratoconus apex localization.Notes: (A) Confocal scan revealed the typical keratoconus changes of a 391 μm thin cornea: stromal keratocytes (white arrow); Vogt’s dark deep striations (red arrows); and pleomorphic endothelium (green arrow). (B) Altimetry map with polar grid superimposition allowing a precise localization of the keratoconus apex in the classic inferior-temporal dislocation (white arrow, red spot).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109632&req=5

f1-opth-8-1337: Confocal pachymetric scan and topographic keratoconus apex localization.Notes: (A) Confocal scan revealed the typical keratoconus changes of a 391 μm thin cornea: stromal keratocytes (white arrow); Vogt’s dark deep striations (red arrows); and pleomorphic endothelium (green arrow). (B) Altimetry map with polar grid superimposition allowing a precise localization of the keratoconus apex in the classic inferior-temporal dislocation (white arrow, red spot).
Mentions: Ten patients with progressive keratoconus, having an average age of 21 years (range 13–26 years) and thin corneas with an average thinnest point of 384 μm (range 368–391 μm) were enrolled in the treatment protocol. All patients were afflicted with stage III keratoconus according to Krumeich’s staging with clinical and instrumental progression in the last 6 months of observation (increased K average >1 Diopter, optical pachymetry difference >10 μm, uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) worsening of at least of 0.1 decimal equivalent). Patients underwent clinical and instrumental pre-operative evaluation before the procedure and post-operatively at day 3, and 1, 3, 6, and 12 months follow-up, by corneal topography, tomography, Heidelberg retina tomograph (HRT) in vivo laser scanning confocal microscopy, and endothelial cells’ count. Corneal topography performed with the Eye-Top corneal topographer (C.S.O. Srl, Florence. Italy) with a polar grid superimposition and altimetry algorithm allowed a reliable keratoconus apex geometric localization and together with laser scanning confocal microscopic analysis increase the information on corneal microstructure and thickness useful for a correct treatment planning (Figure 1).

Bottom Line: Thin corneas with a minimum corneal thickness less than 400 μm after epithelial removal represent a contraindication to standard epithelium-off cross-linking (CXL) treatment due to a significant endothelial cell density decrease and potentiality of permanent haze development.However the iatrogenic swelling effect might not be durable throughout the CXL procedure increasing the risk of postoperative complications.According to our clinical and in-vivo micro-morphological results the technique results safe, and efficacious in stabilizing progressive keratoconus and may be considered a valid option in the treatment of thin ectatic corneas alone or in combination with hypoosmolar or dextran-free riboflavin solutions.

View Article: PubMed Central - PubMed

Affiliation: Unità Operativa Complessa di Oculistica, Siena University Hospital, Siena, Italy.

ABSTRACT
Thin corneas with a minimum corneal thickness less than 400 μm after epithelial removal represent a contraindication to standard epithelium-off cross-linking (CXL) treatment due to a significant endothelial cell density decrease and potentiality of permanent haze development. Preoperative swelling of the cornea with hypoosmolar riboflavin solutions broadens the spectrum of CXL indications to thin corneas. However the iatrogenic swelling effect might not be durable throughout the CXL procedure increasing the risk of postoperative complications. The transepithelial CXL technique proposed for thin corneas demonstrated poor clinical results and mid- to long-term keratoconus instability. The epithelial island CXL technique with customized pachymetry-guided epithelial debridement was evaluated by means of in vivo laser scanning confocal microscopy, corneal topography, and clinical examination in a 1-year follow-up, in order to assess if it may be considered an alternative surgical option for keratoconic patients with thin corneas undergoing corneal collagen CXL. According to our clinical and in-vivo micro-morphological results the technique results safe, and efficacious in stabilizing progressive keratoconus and may be considered a valid option in the treatment of thin ectatic corneas alone or in combination with hypoosmolar or dextran-free riboflavin solutions.

No MeSH data available.


Related in: MedlinePlus