CHAPTER 11â•… •â•… Posterior segment Table 11-5.╇ Classification of retinal degenerations
Benign
Predisposing to RD
White without pressure Pigment clumping Diffuse chorioretinal atrophy Peripheral microcystoid changes Pavingstone degeneration Oral pigmentary degeneration Degenerative ‘senile’ retinoschisis
Lattice degeneration Snail track degeneration Zonuloretinal traction tufts Snowflake degeneration
Figure 11-79.╇ Meridional fold with a small break at the base of the fold. (From Tasman WS: Peripheral retinal lesions. In: Yanoff M, Duker JS (eds) Ophthalmology. London, Mosby, 1999.)
Figure 11-78.╇ Enclosed oral bays. (From Tasman WS: Peripheral retinal lesions. In: Yanoff M, Duker JS (eds) Ophthalmology. London, Mosby, 1999.)
Figure 11-80.╇ Pars plana cysts. (Courtesy of Dr. Ralph Eagle. From Tasman WS: Peripheral retinal lesions. In: Yanoff M, Duker JS (eds) Ophthalmology. London, Mosby, 1999.)
Meridional Fold Elevated fold of retina in upper nasal quadrant 20% prevalence Retinal break may occur (Figure 11-79)
Meridional Complex Meridional fold extending to posterior aspect of a ciliary process
Cystic retinal tuft:╇ chalky white, nodular projection (base 0.1–1.0╯mm) of fibroglial tissue; usually nasal; may have pigment at base; increased vitreous adhesion predisposes to tractional tears from PVD; present at birth; occurs in 5% of population; <1% risk of RD, therefore no prophylactic treatment; associated with 10% of RDs; second to lattice degeneration as visible peripheral retinal lesion associated with RD
Normal variation of anatomy at ora serrata
Zonular traction tuft:╇ thin strand of fibroglial tissue extending from peripheral retina anteriorly to a zonule; usually nasal; present at birth; break occurs in 2–10%
Vitreoretinal Tuft
Pars Plana Cyst (Figure 11-80)╇
Small internal projection of retinal tissue
Clear cystoid space between pigmented and nonpigmented ciliary epithelium of pars plana; filled with mucopolysaccharides (hyaluronic acid)
Retinal break may occur
Noncystic retinal tuft:╇ short, thin (base <0.1╯mm) projection of fibroglial tissue; can break off, leaving fragments in vitreous; usually inferonasal; not associated with retinal break; not present at birth
336
Not a true cyst (not lined with epithelium) Occurs in 17% of autopsied eyes