Holmes, Jonathan M.

ABSTRACT Purpose We conducted a pilot randomized clinical trial of office‐based active vision therapy for the treatment of childhood amblyopia to determine the feasibility of conducting a full‐scale randomized clinical trial. Methods A training and certification program and manual of procedures were developed to certify therapists to administer a standardized vision therapy program in ophthalmology and optometry offices consisting of weekly visits for 16 weeks. Nineteen children, aged 7 to less than 13 years, with amblyopia (20/40–20/100) were randomly assigned to receive either 2 hours of daily patching with active vision therapy or 2 hours of daily patching with placebo vision therapy. Results Therapists in diverse practice settings were successfully trained and certified to perform standardized vision therapy in strict adherence with protocol. Subjects completed 85% of required weekly in‐office vision therapy visits. Eligibility criteria based on age, visual acuity, and stereoacuity, designed to identify children able to complete a standardized vision therapy program and judged likely to benefit from this treatment, led to a high proportion of screened subjects being judged ineligible, resulting in insufficient recruitment. There were difficulties in retrieving adherence data for the computerized home therapy procedures. Conclusions This study demonstrated that a 16‐week treatment trial of vision therapy was feasible with respect to maintaining protocol adherence; however, recruitment under the proposed eligibility criteria, necessitated by the standardized approach to vision therapy, was not successful. A randomized clinical trial of in‐office vision therapy for the treatment of amblyopia would require broadening of the eligibility criteria and improved methods to gather objective data regarding the home therapy. A more flexible approach that customizes vision therapy based on subject age, visual acuity, and stereopsis might be required to allow enrollment of a broader group of subjects.

ABSTRACT Purpose. The Minnesota Low‐Vision Reading Test (MNREAD) has been developed to measure reading speed. An abbreviated version of the MNREAD test was developed that presented only three large paragraphs and would be easier for children to complete. Methods. Fifty children ages 8 to 18 years, with normal eye examinations or refractive error alone, underwent testing of reading speed using the MNREAD test. All the children read the standard MNREAD paragraphs starting at the 1.0 logarithm of the minimum angle of resolution (logMAR) level until they could no longer read the subsequent paragraph. Each eye was tested separately, using the second MNREAD card for the left eye. The standard MNREAD reading speed was calculated by plotting the speed for each paragraph, determining the critical print size, then taking the median value of all the paragraphs above the cutoff paragraph. The proposed abbreviated test reading speed was calculated from the median of three large paragraphs (logMAR, 1.0, 0.9, and 0.8). At a second site, 25 children with a variety of ocular conditions were similarly tested using an alternative abbreviated test (logMAR, 1.3, 1.2, and 1.1). The standard and abbreviated reading speeds were then compared between tests and between eyes using generalized estimating equation and intraclass correlation coefficients. Results. The mean reading method speeds with the standard and abbreviated tests were almost identical [177 words per minute (wpm) ± 46 wpm vs. 178 ± 46 wpm, p = 0.43 for normal children and 140 ± 29 wpm vs. 141 ± 33 wpm, p = 0.35 in children with a variety of ocular conditions]. Conclusion. The new abbreviated version of the MNREAD reading speed test yields similar results to the standard MNREAD test in children. The new abbreviated MNREAD test is faster to administer and appears to be particularly useful for children.

ABSTRACT The circumstances under which unintegrated lentivirus DNA can persist and be a functional template for transcription and protein expression are not clear. We constructed and validated the first class I (nonpleiotropic) integrase (IN) mutants for a non-human lentivirus (feline immunodeficiency virus [FIV]) and analyzed both these and known class I human immunodeficiency virus type 1 IN mutants. The FIV IN mutants (D66V and D66V/D118A) had class I properties: Gag/Pol precursor expression, proteolytic processing, particle formation, and reverse transcriptase (RT) production were normal, while the transduction of dividing fibroblasts was prevented and integration was blocked. When injected into rat retinas, the wild-type (WT) vector produced extensive, persistent transgene expression, compared with only rare positive neuronal cells for the IN mutant vector. In contrast, both WT and mutant vectors produced entirely equivalent, effective transduction levels of primary rat neurons (retinal ganglion cells). By testing the hypothesis that the unexpected retinal neuron transduction was related to cell cycle status, we found that when fibroblasts were growth arrested, transduction and internally promoted transgene expression were not inhibited at all by the class I FIV or HIV-1 IN mutations. Cells were then transduced under aphidicolin arrest and were released from the block 48 h later. Vector expression was stable and durable during repeated passaging in WT vector-transduced cells, while the release of cells transduced with equivalent RT units of class I IN mutant FIV or HIV vector resulted in a steady decline of expression, from 97 to 0% of cells by day 10. Southern blot and PCR analyses showed a lack of integration, irrespective of cell cycle, for the class I mutants and an increase in one- and two-long terminal repeat circular and linear unintegrated DNAs in growth-arrested cells. We conclude that if cell division is prevented, unintegrated FIV and HIV-1 vector DNAs can produce high-level internally promoted transgene expression equivalent to WT vectors. The expression correlates with the unintegrated DNA levels. These observations may facilitate the study of the roles of IN and other preintegration complex components in preintegration phases of infection by (i) providing an alternative way to monitor unintegrated nuclear cDNA forms, (ii) restricting ascertainment to the transcriptionally functional subset of unintegrated DNA, (iii) enabling analysis in individual, nondividing cells, and (iv) uncoupling other potential functions of IN from integration.