CHAPTER 11â•… •â•… Posterior segment
Figure 11-82.╇ Pavingstone degeneration. (Courtesy of Dr. Ralph Eagle. From Tasman WS: Peripheral retinal lesions. In: Yanoff M, Duker JS (eds) Ophthalmology. London, Mosby, 1999.)
Figure 11-83.╇ Lattice degeneration showing the typical white lines. (From Tasman WS: Peripheral retinal lesions. In: Yanoff M, Duker JS (eds) Ophthalmology. London, Mosby, 1999.)
Pathology:╇ degeneration of choroid and retina; loss of
1 in 10,000/year; retinal break can be found in 97%
outer retinal layers; RPE absent; firm adhesion between retina and Bruch’s membraneâ•›/â•›choroid (no predisposition to RD) (Figure 11-82)
Most tears (70%) are located superiorly between 10 and 2 o’clock positions
Lattice Degeneration Occurs in 7% of population; more common in myopic eyes; no sex predilection Often bilateral; usually superotemporal Present in 20–35% of eyes with RD; 0.5% risk that patient with lattice will develop an RD
Findings:╇ peripheral circumferential cigar-shaped atrophic retinal patches; criss-crossing pattern of sclerosed vessels (fine white lines) within lesion in 12%; superficial white dots in 80% (ILM and inner retina); pigmentary disturbance in 82%; firm adhesions of vitreous at margins; clear pockets of vitreous fluid over central thin portion; retinal breaks (round or atrophic holes) in 18%, horseshoe tear in 1.4% at posterior or lateral edge due to severe vitreous traction (Figure 11-83) Pathology:╇ discontinuity of ILM, overlying pocket of liquid vitreous, condensation and adherence of vitreous at margin of lesion, focal area of retinal thinning with loss of inner retinal layers, melanin-laden macrophages, fibrous thickening of retinal vessel walls
Types of breaks: Horseshoe tear Atrophic hole: myopia, increasing age Dialysis: splitting of vitreous base (usually inferotemporally, second most common site is superonasal); traumatic or idiopathic Giant tear: greater than 3 clock hours or 90°; trauma (≥90%), myopia; 50% risk of RD in fellow eye Operculated hole: fragment of retinal tissue found in overlying vitreous
Risk factors:╇ age, history of RD in fellow eye (15%), high myopia╛/╛axial length (7%), family history, lattice degeneration, trauma, cataract surgery (1% after ICCE; 0.1% after ECCE with intact posterior capsule), diabetes, Nd╛:╛YAG laser posterior capsulotomy After blunt trauma, dialysis is most common form of tear, followed by giant retinal tear, flap tear, and tear around lattice degeneration
Symptoms:╇ flashes and floaters in 50% Findings:╇ retinal break; detached retina is opaque,
Treatment:╇ no proof that prophylactic treatment prevents RD; consider treatment of fellow eye if history of RD from lattice
corrugated, and undulates; tobacco dust (pigment in vitreous); decreased IOP; VH; nonshifting subretinal fluid Long-standing RD: thin retina, small breaks or dialysis, demarcation lines, underlying RPE atrophy, subretinal precipitates, macrocysts; may have increased IOP, PVR
Detachments
DDx:╇ exudative or traction RD
Rhegmatogenous Retinal Detachment (RD) Etiology:╇ retinal break allows liquid vitreous access to subretinal space (Figures 11-84 and 11-85)
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Treatment: Pneumatic retinopexy: ideal if RD caused by single break in superior 8 clock hours or multiple breaks within