Gallemore's Corner
Ron Gallemore, M.D.
March 2015
When a PVD is just the tip of the Iceberg
Over their lifetime nearly all patients will develop a posterior vitreous detachment (PVD). As you know, this is a precursor to a retinal tear and retinal detachment. Hear we review the finding and indications for referral.
Diagnosis: A complete PVD can only be diagnosed when a Weiss ring is present. Interestingly, the term complete implies that the vitreous is separated completely. This, in fact, is never the case acutely. It may take several months or even years for the vitreous to completely separate. Most of the separation occurs in the first 3 months. Always check the fellow eye as occult PVD may be present.
Signs of a retinal tear: The presence of a retinal tear secondary to a PVD is our main concern and is classically associated with pigmented cells in the vitreous (Shaffer’s sign). In about 10% of cases pigmented cells may be overlooked. Other associated signs include vitreous hemorrhage, epiretinal membrane (15% chance of associated tear) and any peripheral retinal changes like pigmentation or retinal hemorrhages. Acute, symptomatic PVD is associated with a tear in about 2% of cases. Macular hole, epiretinal membrane, and vitreomacular traction syndrome can also occur with a PVD.
Pseudophakic eyes: A symptomatic PVD after cataract extraction or YAG capsulotomy carries an increased risk of occult retinal tears. These tears tend to be smaller and more difficult to localize.
Time of onset: Retinal tears tend to occur 1-3 mo after a PVD, most often the first week in a high myope and w/in 3 mo in all-comers. If PVD symptoms were recent – days to weeks - the next follow-up exam should be of a similar interval. Over 3 mo and a recheck in 6-12 months may be reasonable. The lack of follow-up following a PVD is a main reason for progression to retinal detachment. Acute, symptomatic PVDs are associated with tears 10-15% of the time.
High myopes: Myopes have a higher risk of tears following a PVD – 5 fold greater if 3D or less, 10 fold greater if >3D. If lattice is present, progression to RD is as high as 25%. Retinal detachments following a PVD also occur faster in highly myopic patients so prompt referral of a symptomatic patient is warranted. Clear lens extraction in high myopes carries a 10-20% risk of RD and preoperative retinal clearance is warranted.
Trauma: Blunt head and eye trauma may precipitate a PVD. One in 10 cases of retinal detachment will reveal a history of significant ocular or head trauma. Late onset detachment can occur and a lifetime of monitoring is required.
Screening with Optos: An excellent way to pick up occult tears and detachments, particularly chronic lesions which may be associated pigment changes. Acute small breaks can be missed.
Summary: Patients with a symptomatic PVD warrants a careful retinal exam. Prompt referral should be considered for acute PVDs (< 3mo), and PVD in eyes with positive Shaffer's sign, field loss, high myopia, pseudophakia, family history of retinal detachment, or history of trauma. Retinal detachments are preventable in many cases by following these guidelines.
Ron P. Gallemore, M.D, Ph.D.
Founder and Director
Retina Macula Institute
South Bay 310-944-9393
Downtown 323-464-9393
Over their lifetime nearly all patients will develop a posterior vitreous detachment (PVD). As you know, this is a precursor to a retinal tear and retinal detachment. Hear we review the finding and indications for referral.
Diagnosis: A complete PVD can only be diagnosed when a Weiss ring is present. Interestingly, the term complete implies that the vitreous is separated completely. This, in fact, is never the case acutely. It may take several months or even years for the vitreous to completely separate. Most of the separation occurs in the first 3 months. Always check the fellow eye as occult PVD may be present.
Signs of a retinal tear: The presence of a retinal tear secondary to a PVD is our main concern and is classically associated with pigmented cells in the vitreous (Shaffer’s sign). In about 10% of cases pigmented cells may be overlooked. Other associated signs include vitreous hemorrhage, epiretinal membrane (15% chance of associated tear) and any peripheral retinal changes like pigmentation or retinal hemorrhages. Acute, symptomatic PVD is associated with a tear in about 2% of cases. Macular hole, epiretinal membrane, and vitreomacular traction syndrome can also occur with a PVD.
Pseudophakic eyes: A symptomatic PVD after cataract extraction or YAG capsulotomy carries an increased risk of occult retinal tears. These tears tend to be smaller and more difficult to localize.
Time of onset: Retinal tears tend to occur 1-3 mo after a PVD, most often the first week in a high myope and w/in 3 mo in all-comers. If PVD symptoms were recent – days to weeks - the next follow-up exam should be of a similar interval. Over 3 mo and a recheck in 6-12 months may be reasonable. The lack of follow-up following a PVD is a main reason for progression to retinal detachment. Acute, symptomatic PVDs are associated with tears 10-15% of the time.
High myopes: Myopes have a higher risk of tears following a PVD – 5 fold greater if 3D or less, 10 fold greater if >3D. If lattice is present, progression to RD is as high as 25%. Retinal detachments following a PVD also occur faster in highly myopic patients so prompt referral of a symptomatic patient is warranted. Clear lens extraction in high myopes carries a 10-20% risk of RD and preoperative retinal clearance is warranted.
Trauma: Blunt head and eye trauma may precipitate a PVD. One in 10 cases of retinal detachment will reveal a history of significant ocular or head trauma. Late onset detachment can occur and a lifetime of monitoring is required.
Screening with Optos: An excellent way to pick up occult tears and detachments, particularly chronic lesions which may be associated pigment changes. Acute small breaks can be missed.
Summary: Patients with a symptomatic PVD warrants a careful retinal exam. Prompt referral should be considered for acute PVDs (< 3mo), and PVD in eyes with positive Shaffer's sign, field loss, high myopia, pseudophakia, family history of retinal detachment, or history of trauma. Retinal detachments are preventable in many cases by following these guidelines.
Ron P. Gallemore, M.D, Ph.D.
Founder and Director
Retina Macula Institute
South Bay 310-944-9393
Downtown 323-464-9393