Ultraviolet Biomicroscopy of the Cornea

1
Ultraviolet Biomicroscopy of the Cornea

• Anthony C B Molteno
• Sean G Every
• Tui H Bevin
• John P Leader
• Giles Wynn-Williams
• Gordon Sanderson
• Ian Bretherton

2
UV Microscopy Unstained section, showing
cellular detail due to selective absorption of
UVB light (290nm) by proteins and nucleic acids
X2000
August Köhler 1904 Ultraviolet (UV) microscopy
was introduced by August Köhler (of Zeiss) in
1904. Short wavelength UV light increased the
resolving power of the microscope and furthermore
in was found that tissues did not require
staining since the nuclei and cytoplasmic
organelles were opaque to UV light. As you see
this photograph, recognisable fibroblasts and
macrophages are phagocytosing apoptotic bodies.
3
UV Camera Light Source Xenon Arc
Quartz/Fluorite Lenses The cornea is transparent
to visible light and signs of corneal disease are
generally subtle and unobstrusive until the
disease is fairly advanced. Glass is opaque to
short wavelength UV light and the optics of a UV
biomicroscope require quartz and fluorite
components to produce an objective that has the
same focus in both visible and short wavelength
UV light. The toxicity of UV light falls off
steeply with increasing wavelength and at a
wavelength of 315 - 325 nm the light is well
tolerated and shows significant detail in cornea,
conjunctiva and sclera that is not shown in
visible light.
4
Normal Cornea - Second Decade Bilateral UV
photographs of an 11 year old male The most
striking difference between UV and visible images
of the cornea is the dense absorption by ferritin
in the corneal epithelium which delineates the
Hudson-Stahli line. This line appears in early
childhood and is visible in UV light in 100 of
cases.
5
Normal Cornea - Third Decade Bilateral UV
photographs of a 21 year old female. With
increasing age ferritin deposition increases and
the Hudson-Stahli line becomes more prominent and
extensive. Darkening of the sclera appears in
the palpebral aperture.
6
Normal Cornea - Fifth Decade Bilateral UV
photographs of a 43 year female. These changes
progress with increasing age but the
Hudson-Stahli remains below the visual axis.
7
Normal Cornea - Seventh Decade Bilateral UV
photographs of a 68 year female. These changes
progress with increasing age but the
Hudson-Stahli remains below the visual axis.
8
Normal Cornea - Ninth Decade Bilateral UV
photographs of an 82 year male. These changes
progress with increasing age but the
Hudson-Stahli remains below the visual axis.
9
Comparison of Prussian Blue Staining and UV
Photography Cadaver Cornea Left, Prussian blue
stain Right, UV photograph Prussian blue
staining shows the distribution of iron in an 89
year old cadaver cornea matching that shown by UV
photography.
10
3 years Post-LASIK Bilateral correction of
Myopia UV photographs of a 34 year old male with
unknown preoperative refraction. Both corneas
showed central stellate patterns. Three years
after LASIK correction of myopia the growth
pattern of the corneal epithelium has altered to
produce stellate depositions of ferritin on the
visual axes in a 34 year old male.
11
6 years Post-LASIK Bilateral correction of
Myopia UV photographs of a 38 year old female
Preop refractions R -6.25/-0.50 x 180 and L
-5.25/-0.75 x 70. Both corneas show central
stellate patterns. Six years after LASIK
correction of myopia the growth pattern of the
corneal epithelium has altered to produce marked
stellate deposition on the visual axes of a 38
year old female.
12
Bilateral Post-LASIK Ectasia UV photographs of
a 43 year old female who had LASIK surgery for
myopia in 1997, and post-operatively had
undergone progressive ectasia corrected with
rigid gas permeable lenses left, a ring
incomplete nasally right, a ring incomplete
inferiorly with a small limb extending nasally
from the crest. Seven years after LASIK surgery
for myopia with progressive ectasia corrected
with rigid gas permeable lenses the epithelial
growth pattern has altered to produce incomplete
ferritin rings in a 43 year old female.
13
Conclusions

• UVB photography of the cornea demonstrates
• The normal growth pattern of the epithelium
• Increasing accumulation of ferritin in ageing
  cells
• The formation of Hudson Stahli lines below the
  visual axis in the normal eye
• The formation of stellate deposits of ferritin
  on the visual axis after refractive surgery
• Provides an exciting new tool for investigating
  corneal changes

14
The questions that remain subject to further
investigation are LASIK or other procedure
alters epithelial growth patterns to produce a
stellate deposition of ferritin on the visual
axis will this deposit increase over the years in
the same way as the Hudson-Stahli line? Will this
increasing deposition of ferritin produce
relentlessly increasing glare and blurring of
vision in middle and old age? References Molten
o ACB, Wynn-Williams G, Every SG, Bevin TH,
Photography of the living human cornea in
ultraviolet light. Australasian Physical and
Engineering Sciences in Medicine 2004
2722-4. Every SG, Leader JP, Molteno ACB, Bevin
TH, Sanderson G. Ultraviolet photography of the
in vivo human cornea unmasks the Hudson-Stahli
line and physiologic vortex patterns.
Investigative Ophthalmology and Visual Science
2005 463616-22.