Transcript Imaging the Posterior Segment Through a PMMA Keratoprosthesis

Imaging the Posterior Segment
Through a PMMA
Keratoprosthesis
Aisha Traish MD, Kathryn Colby MD, PhD
World Cornea Congress VI
April 7-9, 2010
The authors have no financial interest.
Purpose
•
To describe imaging modalities to evaluate the
posterior segment through the Boston
keratoprosthesis Type I (KPro).
Methods
•
Retrospective analysis of all cases of Boston
Kpro Type I patients of the Cornea Service at
the Massachusetts Eye and Ear Infirmary
(2006-2007) who had limited post operative
visual results with clear visual axes. Patients
underwent complete ophthalmic evaluations
and varying posterior segment imaging studies.
Case 1

81 year old retired physician s/p KPro OD
 Ocular hx:
– S/p two penetrating keratoplasties (PKPs) for
pseudophakic bullous keratopathy (PBK) OD

Post-operative vision after KPro was limited
despite a clear anterior visual axis
 Posterior imaging elucidated advancing
macular degeneration as the etiology limiting
his visual potential (see figures #1 and #2)
Figure 1: This fundus
photograph of the right eye
demonstrates calcified drusen
scattered in the macula,
particularly along the superotemporal and infero-temporal
arcades with some geographic
atrophy.
Figure 2: This fluorescein
angiogram of the right eye at 18.8
seconds demonstrates a window
defect consistent with geographic
atrophy; the absence of leakage
excludes a choroidal neovascular
membrane.
Case 2

87 year old male s/p keratoprothesis OD
following three failed PKPs for PBK
 History of glaucoma right eye
 Post operative vision 20/60 declined to
20/100
 no obvious anterior segment pathology
 OCT imaging performed (see figure #3)
Figure 3: This grey scale OCT of the posterior segment in the
right eye was performed post K pro implantation and illustrates
clinically significant cystoid macular edema.
Case 3





56 year old woman with Stevens-Johnson Syndrome
s/p KPro OS
Ocular history: PKP x 2, Open globe repair, Ahmed
valve placement left eye
Postoperative vision: J16 at near, having trouble
reading
SLO demonstrated irregular scotomas (see figure #4)
Recognition of her fixation within the scotoma
allowed for low vision training to adapt her reading
behavior
Figure 4: This scanning laser ophthalmoscope (SLO) image was taken of the
left eye and illustrates irregular scotomas in the central field. The areas
enclosed with grey lines and grey diagonal marks represent scotomas, while
the areas of red dots represent seeing areas. Therefore, her center of fixation
(black cross) lies within a scotoma.
Conclusion
Current posterior segment
imaging modalities can be
successfully used in
patients with a
keratoprosthesis and may
aid the clinician in
diagnosing post-operative
posterior segment
pathology that may limit
visual potential.
Dedicated to Claes Dohlman, MD.