ABSTRACT
The efficacy of combined acyclovir and steroid therapy in the treatment of herpetic stromal disease was evaluated by clinical evaluation of disease, the rebound of disease following termination of therapy, and the recovery of virus and viral DNA from corneas in a rabbit model. Therapy with acyclovir alone produced a significant reduction in corneal thickness in 10% of eyes. Addition of steroid to acyclovir therapy decreased the severity of stromal disease as measured by corneal thickness and increased the frequency of response to treatment to 63% of eyes. All eyes receiving acyclovir alone experienced rebound of disease following termination of therapy. Combined therapy increased the severity of rebound of corneal disease. Virus was recovered from cell cultures established after recovery from rebound in 50% of untreated and treated eyes. Viral DNA was detected by PCR in five of the nine corneal cultures which did not produce infectious virus.
Subject(s)
Acyclovir/therapeutic use , Antiviral Agents/therapeutic use , Corneal Stroma/virology , Glucocorticoids/therapeutic use , Keratitis, Herpetic/drug therapy , Prednisolone/analogs & derivatives , Animals , Corneal Stroma/pathology , DNA, Viral/analysis , Drug Therapy, Combination , Herpesvirus 1, Human/genetics , Herpesvirus 1, Human/isolation & purification , Keratitis, Herpetic/pathology , Male , Ophthalmic Solutions , Polymerase Chain Reaction , Prednisolone/therapeutic use , Rabbits , Random Allocation , Recurrence , Trigeminal Ganglion/virology , Virus Activation/drug effects , Virus Shedding/drug effectsABSTRACT
PURPOSE: To determine the temporal and spatial pattern of rod opsin appearance in Macaca monkey retina. METHODS: Frozen sections from fetal day (Fd) 55 to adulthood (birth = Fd168) containing the entire horizontal meridian were stained using Rho4D2 monoclonal antiserum visualized with immunofluorescent labeling. At Fd66, Fd79, and Fd89, retinal samples taken at known eccentricities were studied from the opposite eye using standard electron microscope methods. RESULTS: Rod opsin was detected at Fd66 in or near the fovea, and a second focus appeared at Fd75 to Fd77 near the optic disc in the nasal rod ring. The earliest opsin appeared in the apical stubs, which resembled the apical connecting cilium in the electron microscope. Staining of the entire cell body membrane, including the synaptic spherule, was present 4 to 7 days later. Opsin expression had a nasal bias with rods at the nasal ora labeled at Fd140, whereas temporal ora was not labeled until Fd155. Cell body labeling disappeared by Fd132 across central retina but persisted into the first postnatal year in far peripheral retina. Outer segment (OS) length measurements showed that rods in the rod ring had the longest OS between Fd115 and postnatal week 9. Rod OS at all retinal eccentricites continued to elongate between 11 months of age and adulthood. CONCLUSIONS: Rod opsin expression follows a foveal-to-peripheral gradient beginning at Fd66 and ending near birth. Rod opsin is detected first in the connecting cilium and slightly later in the entire cell membrane, and then cell membrane labeling disappears as the heavily labeled OS elongates. Although the first OS appear on rods near the fovea, these OS still are short at birth and do not reach adult length until after 2 years of age. The longest OS at birth are found on rods at the rod ring, suggesting that this region could have higher scotopic sensitivity than central retina at birth.
