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. 1987;85:438–470.

RP cone-rod degeneration.

J R Heckenlively 1
PMCID: PMC1298788  PMID: 3447340

Abstract

A group of patients with progressive retinal degeneration and visual field loss, who meet the basic definition of RP were investigated to better define the relationship of the findings on the ERG with clinical characteristics such as visual field size, presence or absence of scotomata or pseudo-altitudinal defects on visual field, amount of night blindness; and presence or absence of macular or optic nerve changes. These studies suggest that cone-rod degeneration patients of the RP type go through the following stages; early, the ERG has a definite cone-rod pattern where the rod ERG is larger than the cone ERG while both are abnormal. As the disease advances, there is more of a reduction in the scotopic ERG such that both the rod and cone ERGs become nearly equal. As the disease further progresses the ERG becomes non-recordable on single-flash technique, but there is good residual rod function and the final rod threshold remains good until the visual field is reduced, typically less than 10 degrees with the IV-4 isopter. Finally with advanced disease the patient becomes night blind and generally becomes very difficult to distinguished from patients who have advanced rod-cone degeneration. While it may seem logical to find that visual field size correlates with various ERG parameters; this has not been as consistent a finding in patients with rod-cone degeneration in the author's experience. The analysis shows several new pieces of information about visual field changes in cone-rod degeneration; enlarged blind spots are seen earlier in cases which have recordable cone-rod patterns (group I), and pseudo-altitudinal changes are more likely to occur in autosomal recessive patients. Patients with macular lesions and central scotomata had larger amplitudes than patients with normal appearing maculae and no central scotomata. Patients with temporal optic atrophy had an earlier onset of symptoms and significant correlation with both photopic a- and b-waves and bright flash dark-adapted b-wave implicit times. Macular edema was present in patients with smaller amplitudes and longer implicit times which suggest that these patients have greater panretinal dysfunction which correlates with the macular alterations. Pigment changes within the classes of none, mild, and moderate deposition correlated with ERG parameters; there was more pigment in cases where ERG parameters were worse. However, cases with heavy pigmentation did not correlate with the ERG degree of severity, suggesting that independent factors influence the amount of pigmentation that occurs in these cases.

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Selected References

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  1. Babel J., Stangos N. Progressive degeneration of the photopic system. Am J Ophthalmol. 1973 Mar;75(3):511–525. doi: 10.1016/0002-9394(73)91167-7. [DOI] [PubMed] [Google Scholar]
  2. Berson E. L., Gouras P., Gunkel R. D., Myrianthopoulos N. C. Dominant retinitis pigmentosa with reduced penetrance. Arch Ophthalmol. 1969 Feb;81(2):226–234. doi: 10.1001/archopht.1969.00990010228013. [DOI] [PubMed] [Google Scholar]
  3. Berson E. L., Gouras P., Gunkel R. D. Progressive cone-rod degeneration. Arch Ophthalmol. 1968 Jul;80(1):68–76. doi: 10.1001/archopht.1968.00980050070010. [DOI] [PubMed] [Google Scholar]
  4. Berson E. L., Gouras P., Hoff M. Temporal aspects of the electroretinogram. Arch Ophthalmol. 1969 Feb;81(2):207–214. doi: 10.1001/archopht.1969.00990010209011. [DOI] [PubMed] [Google Scholar]
  5. Ederer F. Refereeing clinical research papers for statistical content. Am J Ophthalmol. 1985 Nov 15;100(5):735–737. doi: 10.1016/0002-9394(85)90633-6. [DOI] [PubMed] [Google Scholar]
  6. Fishman G. A., Alexander K. R., Anderson R. J. Autosomal dominant retinitis pigmentosa. A method of classification. Arch Ophthalmol. 1985 Mar;103(3):366–374. doi: 10.1001/archopht.1985.01050030062023. [DOI] [PubMed] [Google Scholar]
  7. Fishman G. A., Rhee A. J., Blair N. P. Blood-retinal barrier function in patients with cone or cone-rod dystrophy. Arch Ophthalmol. 1986 Apr;104(4):545–548. doi: 10.1001/archopht.1986.01050160101022. [DOI] [PubMed] [Google Scholar]
  8. GOODMAN G., RIPPS H., SIEGEL I. M. CONE DYSFUNCTION SYNDROMES. Arch Ophthalmol. 1963 Aug;70:214–231. doi: 10.1001/archopht.1963.00960050216013. [DOI] [PubMed] [Google Scholar]
  9. GOURAS P., CARR R. E. ELECTROPHYSIOLOGICAL STUDIES IN EARLY RETINITIS PIGMENTOSA. Arch Ophthalmol. 1964 Jul;72:104–110. doi: 10.1001/archopht.1964.00970020106022. [DOI] [PubMed] [Google Scholar]
  10. Heckenlively J. R., Martin D. A., Rosales T. O. Telangiectasia and optic atrophy in cone-rod degenerations. Arch Ophthalmol. 1981 Nov;99(11):1983–1991. doi: 10.1001/archopht.1981.03930020859009. [DOI] [PubMed] [Google Scholar]
  11. Heckenlively J. R., Martin D. A., Rosenbaum A. L. Loss of electroretinographic oscillatory potentials, optic atrophy, and dysplasia in congenital stationary night blindness. Am J Ophthalmol. 1983 Oct;96(4):526–534. doi: 10.1016/s0002-9394(14)77917-6. [DOI] [PubMed] [Google Scholar]
  12. Krauss H. R., Heckenlively J. R. Visual field changes in cone-rod degenerations. Arch Ophthalmol. 1982 Nov;100(11):1784–1790. doi: 10.1001/archopht.1982.01030040764011. [DOI] [PubMed] [Google Scholar]
  13. Krill A. E., Fishman G. A. Acquired color vision defects. Trans Am Acad Ophthalmol Otolaryngol. 1971 Sep-Oct;75(5):1095–1111. [PubMed] [Google Scholar]
  14. Marmor M. F. The electroretinogram in retinitis pigmentosa. Arch Ophthalmol. 1979 Jul;97(7):1300–1304. doi: 10.1001/archopht.1979.01020020042009. [DOI] [PubMed] [Google Scholar]
  15. Marmor M. F. Visual loss in retinitis pigmentosa. Am J Ophthalmol. 1980 May;89(5):692–698. doi: 10.1016/0002-9394(80)90289-5. [DOI] [PubMed] [Google Scholar]
  16. Miyake Y., Goto S., Ota I., Ichikawa H. Vitreous fluorophotometry in patients with cone-rod dystrophy. Br J Ophthalmol. 1984 Jul;68(7):489–493. doi: 10.1136/bjo.68.7.489. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Pruett R. C. Retinitis pigmentosa: clinical observations and correlations. Trans Am Ophthalmol Soc. 1983;81:693–735. [PMC free article] [PubMed] [Google Scholar]
  18. Retinitis pigmentosa. A symposium on terminology and methods of examination. Ophthalmology. 1983 Feb;90(2):126–131. [PubMed] [Google Scholar]
  19. Ross D. F., Fishman G. A., Gilbert L. D., Anderson R. J. Variability of visual field measurements in normal subjects and patients with retinitis pigmentosa. Arch Ophthalmol. 1984 Jul;102(7):1004–1010. doi: 10.1001/archopht.1984.01040030806021. [DOI] [PubMed] [Google Scholar]
  20. WALD G., ZEAVIN B. H. Rod and cone vision in retinitis pigmentosa. Am J Ophthalmol. 1956 Oct;42(4 Pt 2):253–269. doi: 10.1016/0002-9394(56)90377-4. [DOI] [PubMed] [Google Scholar]

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