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Klin Monbl Augenheilkd 2022; 239(02): 233-252
DOI: 10.1055/a-1671-0980
CME-Fortbildung

Detektion des subklinischen Keratokonus

Detection of Subclinical Keratoconus
Stephan Degle
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Zusammenfassung

Das Frühstadium eines Keratokonus, ohne klassische und kennzeichnende klinische Befunde, stellt eine Kontraindikation für refraktive Chirurgie dar. Dieser Beitrag zeigt deshalb gemäß dem aktuellen Stand der Technik Möglichkeiten auf, Risikofaktoren für einen subklinischen Keratokonus zu erkennen.

Abstract

The early stage of a keratoconus (KC), without classic and characteristic clinical findings, is a contraindication for refractive surgery. This article therefore shows, in accordance with the current state of the art, ways of identifying risk factors for subclinical keratoconus.

After delimitation, this publication contains a current summary of epidemiology, etiology and pathophysiology of subclinical and clinical KC. Furthermore, an overview of different grading scales is given. A detailed description of several practical possibilities for detection of subclinical KC is the focus of this publication: typical abnormalities with subclinical KC in ocular aberrometry, corneal topography, Zernike analysis, Fourier analysis, indices of the corneal anterior surface; especially tomography of the anterior segment of the eye respecting addition of the corneal posterior surface and the pachymetry, and also innovative techniques counting in the rigidity or biomechanical properties, as well as traditional techniques giving hints for subclinical KC as retinoscopy, ophthalmoscopy and subjective refraction.

In preparation for refractive surgical interventions and to avoid possible consequences of subclinical KC, a suitable analysis with different methods should always be carried out in addition to a specific anamnesis. An exclusive consideration of the available indices is not sufficient, as this does not reveal early stages. Ideally, the biomechanics of the cornea is included in the diagnosis. The combination of tomography and biomechanics with methods of artificial intelligence are trendsetting in detection of subclinical KC.

Kernaussagen

  • Ziel der Erkennung des Keratokonus (KK) im subklinischen Stadium ist es, den Patienten frühzeitig über eine mögliche Progression und Komplikationen aufzuklären und diese zu minimieren.

  • Das Erkennen eines subklinischen Keratokonus ist vor refraktivchirurgischen Eingriffen von großer Bedeutung, um postoperative Komplikationen einer raschen Progression zu vermeiden.

  • Auch Patienten ohne einseitigen klinischen Keratokonus sollten vor refraktivchirurgischen Eingriffen auf Anzeichen von subklinischen Keratokonus untersucht werden.

  • Traditionelle Klassifikationen des klinischen Befunds sind für eine Früherkennung nicht geeignet.

  • Eine aberrometrische Auswertung der HOA (Aberrationen höherer Ordnung) und tomografische Verfahren, die Vorder- und Rückfläche und Dicke der Hornhaut berücksichtigen und diese mit Normwerten vergleichen, können subklinische Formen des Keratokonus detektieren. Speziell sind hier Differenzenvergleiche im Zeitverlauf zu empfehlen. Hilfreich sind ergänzend auch Hinweise aus der Anamnese, der subjektiven Bestimmung sowie der Skiaskopie und Ophthalmoskopie.

  • Die Kombination von Tomografie und Biomechanik mit Methoden der künstlichen Intelligenz sind in der Früherkennung von Keratokonus richtungsweisend.

Schlüsselwörter

subklinischer Keratokonus - Keratokonus-Klassifikation - Topografie - Tomografie - Rigidität der Hornhaut

Key words

subclinical keratoconus - keratoconus grading - topography - tomography - corneal biomechanics


Publication History

Article published online:
19 November 2021

© 2021. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 

  • Literatur

  • 1 Burns DM, Johnston FM, Frazer DG. et al. Keratoconus: an analysis of corneal asymmetry. Br J Ophthalmol 2004; 88: 1252-1255
    CrossrefPubMedGoogle Scholar
  • 2 Bühren J, Kook D, Yoon G. et al. Detection of subclinical keratoconus by using corneal anterior and posterior surface aberrations and thickness spatial profiles. Invest Ophthalmol Vis Sci 2010; 51: 3424-3432
    CrossrefPubMedGoogle Scholar
  • 3 Johnson RD, Nguyen MT, Lee N. et al. Corneal biomechanical properties in normal, forme fruste keratoconus, and manifest keratoconus after statistical correction for potentially confounding factors. Cornea 2011; 30: 516-523
    CrossrefPubMedGoogle Scholar
  • 4 Klyce SD. Chasing the suspect: keratoconus. Br J Ophthalmol 2009; 93: 845-847
    CrossrefPubMedGoogle Scholar
  • 5 Schweitzer C, Roberts CJ, Mahmoud AM. et al. Screening of forme fruste keratoconus with the ocular response analyzer. Invest Ophthalmol Visual Sci 2010; 51: 2403-2410
    CrossrefPubMedGoogle Scholar
  • 6 Cameron JA. Keratoglobus. Cornea 1993; 12: 124-130
    CrossrefPubMedGoogle Scholar
  • 7 Seiler T, Koufala K, Richter G. Iatrogenic keratectasia after laser in situ keratomileusis. J Refract Surg 1998; 14: 312-317
    CrossrefPubMedGoogle Scholar
  • 8 Seiler T, Quurke AW. Iatrogenic keratectasia after LASIK in a case of forme fruste keratoconus. J Cataract Refract Surg 1998; 24: 1007-1009
    CrossrefPubMedGoogle Scholar
  • 9 Ihalainen A. Clinical and epidemiological features of keratoconus genetic and external factors in the pathogenesis of the disease. Acta Ophthalmol Suppl 1986; 178: 1-64
    PubMedGoogle Scholar
  • 10 Assiri AA, Yousuf BI, Quantock AJ. et al. Incidence and severity of keratoconus in Asir province, Saudi Arabia. Br J Ophthalmol 2015; 89: 1403-1406
    CrossrefPubMedGoogle Scholar
  • 11 Georgiou T, Funnell CL, Cassels-Brown A. et al. Influence of eth- nic origin on the incidence of keratoconus and associated atopic disease in Asians and white patients. Eye 2004; 18: 379-383
    CrossrefPubMedGoogle Scholar
  • 12 Jacobs DS, Dohlman CH. Is keratoconus genetic?. Int Ophthalmol Clin 1993; 33: 249-260
    CrossrefPubMedGoogle Scholar
  • 13 Kok YO, Tan GFL, Loon SC. Review: Keratoconus in Asia. Cornea 2012; 31: 581-593
    CrossrefPubMedGoogle Scholar
  • 14 Owens H, Gamble G. A profile of keratoconus in New Zealand. Cornea 2003; 22: 122-125
    CrossrefPubMedGoogle Scholar
  • 15 Pearson AR, Soneji B, Sarvananthan N. et al. Does ethnic origin influence the incidence or severity of keratoconus?. Eye (London) 2000; 14: 625-628
    CrossrefPubMedGoogle Scholar
  • 16 Zadnik K, Barr JT, Edrington TB. et al. Baseline findings in the Collabo- rative Longitudinal Evaluation of Keratoconus (CLEK) Study. Invest Ophthalmol Vis Sci 1998; 39: 2537-2546
    PubMedGoogle Scholar
  • 17 Cullen JF, Butler HG. Mongolism (Downʼs syndrome) and keratoconus. Brit J Ophthalmol 1963; 47: 321-330
    CrossrefPubMedGoogle Scholar
  • 18 Grünauer-Kloevekorn C, Duncker GI. Keratokonus: Epidemiologie, Risikofaktoren und Diagnostik. Klin Monbl Augenheilkd 2006; 223: 493-502
    Article in Thieme ConnectPubMedGoogle Scholar
  • 19 Rabinowitz YS. Keratoconus. Surv Ophthalmol 1998; 42: 297-319
    CrossrefPubMedGoogle Scholar
  • 20 Elder MJ. Leber congenital amaurosis and its association with keratoconus and keratoglobus. J Pediat Ophthalmol Strabism 1994; 31: 38-40
    CrossrefPubMedGoogle Scholar
  • 21 Harrison RJ, Klouda PT, Easty DL. et al. Association between keratoconus and atopy. Br J Ophthalmol 1989; 73: 816-822
    CrossrefPubMedGoogle Scholar
  • 22 Rabinowitz YS, Rasheed K. KISA% index: a quantitative videokeratography algorithm embodying minimal topographic criteria for diagnosing keratoconus. J Cataract Refract Surg 1999; 25: 1327-1335
    CrossrefPubMedGoogle Scholar
  • 23 Sharif KW, Casey TA, Coltart J. Prevalence of mitral valve prolapse in keratoconus patients. J R Soc Med 1992; 85: 446-448
    CrossrefPubMedGoogle Scholar
  • 24 Kim WJ, Rabinowitz YS, Meisler DM. et al. Keratocyte apoptosis associated with keratoconus. Exp Eye Res 1999; 69: 475-481
    CrossrefPubMedGoogle Scholar
  • 25 Jacobs DS, Dohlman CH. Is keratoconus genetic?. Int Ophthalmol Clin 1993; 33: 249-260
    CrossrefPubMedGoogle Scholar
  • 26 Amsler M. The “forme fruste” of keratoconus. Wien Klin Wochenschr 1961; 73: 842-843
    PubMedGoogle Scholar
  • 27 Saad A, Gatinel D. Topographic and tomographic properties of forme fruste keratoconus corneas. Invest Ophthalmol Visual Sci 2010; 51: 5546-5555
    CrossrefPubMedGoogle Scholar
  • 28 Belin MW, Khachikian SS. An introduction to understanding elevation- based topography: how elevation data are displayed – a review. Clin Exp Ophthalmol 2009; 37: 14-29
    CrossrefPubMedGoogle Scholar
  • 29 Rao SN, Raviv T, Majmudar PA. et al. Role of Orbscan II in screening keratoconus suspects before refractive corneal surgery. Ophthalmology 2002; 109: 1642-1646
    CrossrefPubMedGoogle Scholar
  • 30 Schlegel Z, Hoang-Xuan T, Gatinel D. Comparison of and correlation between anterior and posterior corneal elevation maps in normal eyes and keratoconus-suspect eyes. Invest Ophthalmol Visual Sci 2008; 34: 789-795
    PubMedGoogle Scholar
  • 31 Bowman KJ, Carney LG, Collin HB. Bilateral keratoconus posticus circumscriptus: a case report. Am J Optometry Physiol Optics 1979; 56: 435-440
    CrossrefPubMedGoogle Scholar
  • 32 Stoiber J. Die stadiengerechte Therapie des Keratokonus. Klin Monbl Augenheilkd 2008; 225: R121-R136
    Article in Thieme ConnectPubMedGoogle Scholar
  • 33 Krumeich JH, Daniel J. Lebend-Epikeratophakie und Tiefe Lamelläre Keratoplastik zur Stadiengerechten chirurgischen Behandlung des Keratokonus (KK) I–III. Klin Monbl Augenheilkd 1997; 211: 94-100
    Article in Thieme ConnectPubMedGoogle Scholar
  • 34 Degle S, Hoffmann Y. Abhängigkeit der Refraktion von Beleuchtung und Pupillendurchmesser. DOZ 2009; 8: 38-41
    PubMedGoogle Scholar
  • 35 Villavicenico O, Gillani F, Henriquez MA. et al. Independent Population Validation of the Belin/Ambrosio Enhanced Ectasia Display Implications for Keratoconus Studies and Screening. Int J Keratoconus Ectatic Corneal Dis 2014; DOI: 10.5005/jp-journals-10025-1069.
    CrossrefPubMedGoogle Scholar
  • 36 Ambrósio jr. R, Alonso RS, Luz A. et al. Corneal-thickness spatial profile and corneal-volume distribution: Tomographic indices to detect Keratoconus. J Cataract Refract Surg 2006; 32: 1851-1859
    CrossrefPubMedGoogle Scholar
  • 37 Gatzioufas Z, Seitz B. Neues zur Biomechanik der Kornea beim Keratokonus. Ophthalmologe 2013; 110: 810 812–817
    CrossrefPubMedGoogle Scholar
  • 38 Terai N, Raiskup F, Haustein M. et al. Identification of biomechanical properties of the cornea: the ocular response analyzer. Curr Eye Res 2012; 37: 553-562
    CrossrefPubMedGoogle Scholar
  • 39 Shah S, Laiquzzaman M, Bhojwani R. et al. Assessment of the biomechanical properties of the cornea with the ocular response analyzer in normal and keratoconic eyes. Invest Ophthalmol Vis Sci 2007; 48: 3026-3031
    CrossrefPubMedGoogle Scholar
  • 40 Tannhoff H, Parasta AM, Eisenbarth W. Unterschiede der cornealen Biomechanik bei Keratokonus und pelludicer marginaler Degeneration – gemessen mit dem Corvis ST (Bachelorarbeit an der HS München). München; 2017
    Google Scholar
  • 41 Vinciguerra R, Ambrósio jr. R, Elsheikh A. et al. Detection of keratoconus with a new biomechanical index. J Refract Surg 2016; 32: 803-810
    CrossrefPubMedGoogle Scholar
  • 42 Ambrósio jr. R, Lopes BT, Faria-Correia F. et al. Integration of Scheimpflug-1 based corneal tomographic and biomechanical assessments for enhancing ectasia detection. J Refract Surg 2017; 33: 266-273
    CrossrefPubMedGoogle Scholar
  • 43 Chan TCY, Wang YM, Yu M. et al. Comparison of corneal tomography and a new combined tomographic biomechanical index in subclinical keratoconus. J Refract Surg 2018; 34: 616-621
    CrossrefPubMedGoogle Scholar
  • 44 Ferreira-Mendes J, Lopes BT, Faria-Correia F. et al. Enhanced Ectasia Detection Using Corneal Tomography and Biomechanics. Am J Ophthalmol 2019; 197: 7-16
    CrossrefPubMedGoogle Scholar
  • 45 Steinberg J, Siebert M, Katz T. et al. Tomographic and Biomechanical Scheimpflug lmaging for Keratoconus Characterization: A Validation of Current Indices. J Refract Surg 2018; 34: 840-847
    CrossrefPubMedGoogle Scholar
  • 46 Scarelli G, Pineda R, Yun SH. Brillouin optical microscopy for corneal biomechanics. Invest Ophthalmol Vis Sci 2012; 53: 185-190
    CrossrefPubMedGoogle Scholar
  • 47 Chen M, Sabesan R, Ahmad K. et al. Correcting anterior corneal aberration and variability of lens movements in keratoconic eyes with back-surface customized soft contact lenses. Opt Lett 2007; 32: 3203-3205
    CrossrefPubMedGoogle Scholar
  • 48 Vinciguerra R, Ambrósio jr. R, Roberts CJ. et al. Biomechanical characterization of subclinical keratoconus without topographic or tomographic abnormalities. J Refract Surg 2017; 33: 399-407
    CrossrefPubMedGoogle Scholar