Pathology of the Lens

Pathology of the lens

Carol Naranjo, LV, DACVP, DECVP, PhD IDEXX Laboratories Embryonal development

Gelatt’s Veterinary Ophthalmology, 5th Ed. Normal histology

• Lens capsule – Anterior > posterior • Lens cortex – Lens epithelium and lens bow • Lens nucleus

• Artifact! Lens bow

Anterior lens capsule Posterior lens capsule Congenital conditions

• Aphakia

• Microphakia

• Lens coloboma Dr. Dubielzig (COPLOW)

• Spherophakia

• Lenticonus/lentiglobus Lenticonus

Courtesy of Dr. Dubielzig (COPLOW) Cataract

• Any opacification of the lens • Various classifications • Etiology: – Senile, hereditary, diabetic, toxic – Secondary: intraocular inflam, retinal degeneration, glaucoma, neoplasia • Extension of lens involvement – Some variation b/w clinical-pathological assessment • Location Congenital cataract

• Abnormal position or lysis of the nucleus.

• Dysplastic changes in the lens capsule

– Duplication, wrinkling

• Posterior migration of lens epithelium

• Fetal vasculature anomalies Congenital cataract

Courtesy of Dr. Dubielzig (COPLOW) Cataract - location

• Subcapsular – anterior:

– Proliferation of LEC

– LEC fibrous metaplasia

– Collagenous mb Cataract - location

• Subcapsular – posterior: – Migration of lens epithelium – Proliferation, fibrous metaplasia, collagen membranes Cataract - location

• Cortical: – Early/incipient: not always detected – Mature: • Bladder cells • Morgagnian globules – Intumescent: • Lens swelling • Morgagnian globules throughout the cortex

Intumesent cataract

Courtesy of Dr. Dubielzig (COPLOW) Cataract - location • Cortical: – Hypermature: • Lens swelling • Mineralization • Liquefaction • Lens capsule wrinkling – Morgagnian: • Cortex liquefaction, only the nucleus remains • Nuclear: hard to detect histologically Mineralization Cortical liquefaction Lens capsule wrinkling Morgagnian cataract Resorbed cataract Cataract after trauma

• Anterior or posterior subcapsular / cortical • Lens capsule rupture: – Intralenticular cells: • MO, PMNn, RBC, fibroblasts, blood vessels – Margins of the lens capsule: • Proliferating LEC entrapping the edges of the capsule • Spindle cells associated with synechiae • Frayed capsule edges with inflammatory cells. – Scrolling of the edges of lens capsule.

Cataract after trauma

• Inflammation w/ lens capsule rupture (phacoclastic uveitis): – Bland granulomatous inflammation – LP uveitis • Lens epithelium: spindle cell metaplasia, proliferation and migration – BM-like material – Myofibroblastic phenotype • Lens luxation Phacoclastic uveitis Courtesy of Dr. Dubielzig (COPLOW) Courtesy of Dr. Dubielzig Post-cataract surgery Post-cataract surgery lens fiber regrowth Lens luxation

• Separation of lens from the zonular attachment

– Subluxation

– Anterior luxation

– Posterior luxation Lens luxation

• Primary: – Zonular ligament dysplasia – Marfan syndrome • Secondary: – Uveitis – Trauma – Glaucoma – Hypermature cataract – Senile Diagnosing lens luxation

• Clinical diagnosis • Grossly (trimming): – Lens displacement – Vitreous liquefaction • Distorted angle of the iris leaflet (“dogleg”) • Attenuation of the corneal endothelium (axially) • Atrophy of ciliary processes • Position of the lens on the histo slide

Entrapment of the lens “Dog leg” iris Endothelial cell attenuation Ciliary processes atrophy Diagnosing lens luxation (non-specific)

• Cornea: – Edema/corneal ulceration, keratitis, collagenolysis • Retrocorneal membranes • Retinal detachment • Glaucoma: – Pupillary block – PIFM • Inflammation, anterior segment of the globe

Zonular ligament dysplasia

• Terrier breeds (JRT)

– Chinese crested dog, Shar Pei, Australian blue Heeler

• Many breeds w/ ADAMTS17 mutation

• Younger than other dogs with lens lux

• Important for the 2nd eye!

Morris and Dubielzig, 2005 Zonular ligament dysplasia

• Thick lamellar eosinophilic membrane w/ cross- hatching pattern • Intermittent change • Staining properties; – PAS-positive (normal also +ive) – Blue with Masson’s trichrome (normal is red) – Negative for Verhoeff’s elastin stain (normal is +ive)

Special stains

PAS Masson’s trichrome

Normal, from: Morris and Dubielzig, 2005 Primary lens luxation • Inflammation in anterior segment: – Mononuclear – Some PMNs can be seen • Pigmentary changes: – Melanophages and pigment dispersion • Hypertrophy/hyperplasia of post mid-iris epithelium • Loss of pigment epithelium in pupillary margin Alario et al, 2013 Thanks! [email protected]