Visual
Acuity Loss
Relationship
in Retinitis
Pigmentosa
to Visual Field Loss
Steven A. Madreperla, MD, PhD; Rosalind W. Palmer; Robert W. Massof, PhD; Daniel Finkelstein, MD
\s=b\ We compared visual acuity with visual field radius in 235 patients with typical retinitis pigmentosa and no evidence of other visual acuity-limiting problems (such as cataract or foveal cystoid edema). Results show a strong relationship between visual acuity loss and proximity to the fovea of the visual field border (shortest distance from the foveal center to the border of the V-4-e isopter) for these patients. Ninety-six percent of patients with central visual field radii greater than 30\s=deg\have visual acuities of 20/40 or better; 32\s=deg\of patients with central visual field radii smaller than 10\s=deg\have visual acuity of 20/40 or better.
{Arch Ophthalmol. 1990;108:358-361)
/"Wer the past two decades, there has
been increasing interest in studies that document the natural history of retinal function loss in retinitis pig¬ mentosa (RP)17; such studies are of value for a number of reasons: to counsel patients regarding the future, to plan vision rehabilitation programs, to gain insight into the pathophysiologic mechanisms of disease, and to test experimental treatment protocols. Retinitis pigmentosa is a slowly pro¬
gressive retinal degeneration of un¬ known origin; often, but not always, an
inheritance pattern can be ascertained from the family history. Although a precise definition of the disease has not for publication November 18, 1989. From The Wilmer Eye Institute, The Johns Hopkins Medical Institutions, Baltimore, Md. Reprint requests to The Wilmer Eye Institute, The Johns Hopkins Hospital, Baltimore, MD 21205 (Dr Finkelstein).
Accepted
been
reached,8 the clinical hallmarks
present in most typical
include of progressive visual cases
the development field loss, night blindness, midperipheral intraretinal bone spicule pigmen¬ tation, and narrowed retinal arterioles. Frequently, the term retinitis pig¬ mentosa is applied liberally to a di¬ verse group of patients with retinal degenerations. In the present study, we have included only those patients defined as having "typical" RP. Al¬ though we previously have emphasized that a characteristic of typical RP is good visual acuity until late in the course of the disease,7 we stress that the level of visual acuity was not used as an inclusion or exclusion criterion for the present analyses. Our laboratories have had a partic¬ ular interest in the manner in which the peripheral visual field becomes constricted in RP, and we have de¬ scribed the very consistent rate at which that occurs.6'7·9 During these studies, it appeared to us that visual acuity loss did not begin to occur until late in the course of the disease, when the visual field had become quite small. Since it is important to know when vi¬ sual acuity loss due to the retinal degeneration of RP might be expected to occur, we have examined visual acu¬ ity in relation to the radius of the visual field, excluding patients for whom visual acuity loss might be at¬ tributed to other factors (eg, cata¬ ract or cystoid foveal change). We show that, for the majority of pa¬ tients, clinically significant visual acuity loss (to
Acuity Loss
Relationship
in Retinitis
Pigmentosa
to Visual Field Loss
Steven A. Madreperla, MD, PhD; Rosalind W. Palmer; Robert W. Massof, PhD; Daniel Finkelstein, MD
\s=b\ We compared visual acuity with visual field radius in 235 patients with typical retinitis pigmentosa and no evidence of other visual acuity-limiting problems (such as cataract or foveal cystoid edema). Results show a strong relationship between visual acuity loss and proximity to the fovea of the visual field border (shortest distance from the foveal center to the border of the V-4-e isopter) for these patients. Ninety-six percent of patients with central visual field radii greater than 30\s=deg\have visual acuities of 20/40 or better; 32\s=deg\of patients with central visual field radii smaller than 10\s=deg\have visual acuity of 20/40 or better.
{Arch Ophthalmol. 1990;108:358-361)
/"Wer the past two decades, there has
been increasing interest in studies that document the natural history of retinal function loss in retinitis pig¬ mentosa (RP)17; such studies are of value for a number of reasons: to counsel patients regarding the future, to plan vision rehabilitation programs, to gain insight into the pathophysiologic mechanisms of disease, and to test experimental treatment protocols. Retinitis pigmentosa is a slowly pro¬
gressive retinal degeneration of un¬ known origin; often, but not always, an
inheritance pattern can be ascertained from the family history. Although a precise definition of the disease has not for publication November 18, 1989. From The Wilmer Eye Institute, The Johns Hopkins Medical Institutions, Baltimore, Md. Reprint requests to The Wilmer Eye Institute, The Johns Hopkins Hospital, Baltimore, MD 21205 (Dr Finkelstein).
Accepted
been
reached,8 the clinical hallmarks
present in most typical
include of progressive visual cases
the development field loss, night blindness, midperipheral intraretinal bone spicule pigmen¬ tation, and narrowed retinal arterioles. Frequently, the term retinitis pig¬ mentosa is applied liberally to a di¬ verse group of patients with retinal degenerations. In the present study, we have included only those patients defined as having "typical" RP. Al¬ though we previously have emphasized that a characteristic of typical RP is good visual acuity until late in the course of the disease,7 we stress that the level of visual acuity was not used as an inclusion or exclusion criterion for the present analyses. Our laboratories have had a partic¬ ular interest in the manner in which the peripheral visual field becomes constricted in RP, and we have de¬ scribed the very consistent rate at which that occurs.6'7·9 During these studies, it appeared to us that visual acuity loss did not begin to occur until late in the course of the disease, when the visual field had become quite small. Since it is important to know when vi¬ sual acuity loss due to the retinal degeneration of RP might be expected to occur, we have examined visual acu¬ ity in relation to the radius of the visual field, excluding patients for whom visual acuity loss might be at¬ tributed to other factors (eg, cata¬ ract or cystoid foveal change). We show that, for the majority of pa¬ tients, clinically significant visual acuity loss (to
