Implementation of a vision-screening program in rural northeastern United States.

BACKGROUND: Rural populations comprise almost 20% of the US population and face unique barriers in receiving health care. We describe the implementation of a medical student-run free vision-screening clinic as a strategy to overcome barriers in accessing eye care in New Hampshire and Vermont. METHODS: Medical students were trained by an ophthalmologist to administer screening eye examinations. Patients from New Hampshire and Vermont were enrolled through a free community clinic. Screening included a questionnaire, distance and near visual acuity, extraocular movements, confrontational visual fields, and Amsler grid. Patients who met predetermined screening criteria were referred to an ophthalmologist or optometrist for further evaluation. Data including patient demographics, appointment attendance, level of education, and diagnoses were recorded and analyzed. RESULTS: Of 103 patients (mean age of 45.5±12.3 years, 63% female), 74/103 (72%) were referred for further evaluation, and 66/74 (89%) attended their referral appointments. Abnormal ophthalmologic examination findings were observed in 58/66 (88%) patients who attended their referral appointment. Uncorrected refractive error was the most common primary diagnosis in 38% of referred patients. Other diagnoses included glaucoma suspect (21%), retinal diseases (8%), amblyopia (8%), cataract (6%), others (6%), and normal examination (12%). Of the 8/74 (11%) referred patients who did not attend their appointments, reasons included patient cancellation of appointment, work conflicts, or forgetfulness. Patients traveled a mean distance of 16.6 miles (range: 0-50 miles) to attend screening examinations. Mean time for patients' last effort to seek eye care was 7.1 years (range: 1-54 years). CONCLUSION: This study underscores the high prevalence of unmet eye care needs in a rural population. Furthermore, it demonstrates that using community health centers as a patient base for screening can yield a high referral attendance rate for this at-risk population and facilitate entrance into the eye care system in a rural setting.

Visual contrast sensitivity in Alzheimer's disease, mild cognitive impairment, and older adults with cognitive complaints.

Deficits in contrast sensitivity (CS) have been reported in Alzheimer's disease (AD). However, the extent of these deficits in prodromal AD stages, including mild cognitive impairment (MCI) or even earlier, has not been investigated. In this study, CS was assessed using frequency doubling technology in older adults with AD (n = 10), amnestic MCI (n = 28), cognitive complaints without performance deficits (CC; n = 20), and healthy controls (HC; n = 29). The association between CS and cognition was also evaluated. Finally, the accuracy of CS measures for classifying MCI versus HC was evaluated. CS deficits were found in AD and MCI, while CC showed intermediate performance between MCI and HC. Upper right visual field CS showed the most significant difference among groups. CS was also associated with cognitive performance. Finally, CS measures accurately classified MCI versus HC. The CS deficits in AD and MCI, and intermediate performance in CC, indicate that these measures are sensitive to early AD-associated changes. Therefore, frequency doubling technology-based measures of CS may have promise as a novel AD biomarker.

Functional assessment of accommodating intraocular lenses versus monofocal intraocular lenses in cataract surgery: metaanalysis.

PURPOSE: To compare accommodating intraocular lens (IOLs) and monofocal IOLs in restoring accommodation in cataract surgery. SETTING: Dartmouth Medical School and Department of Ophthalmology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA. METHODS: In this metaanalysis, 2 researchers independently extracted data, assessed trial quality, and contacted authors for missing information. Because of measurement-scale variations, outcomes were pooled for distance-corrected near visual acuity (DCNVA) as standardized mean differences with 95% confidence intervals [CIs] and anterior displacement of the lens as weighted mean differences (95% CI). RESULTS: The metaanalysis comprised 12 randomized controlled studies of 727 eyes. Based on 10 studies that compared DCNVA, accommodating IOLs were favored but failed the test of heterogeneity (I(2) = 94%). Pooling the 6 homogeneous trials (I(2) = 43%) showed no difference (standardized mean difference, -0.16; 95% CI, -0.56 to 0.25). Heterogeneity could not be explained by any characteristic of the study population or methodology. Based on 4 studies that evaluated pilocarpine-induced IOL shift, there was a significant anterior compared with the control (weighted mean difference, 95% CI, -0.36 - 0.47 to -0.24]), although the studies were heterogeneous (I(2) = 58%). Three of 5 studies mentioning posterior capsule opacification (PCO) reported increased rates in the accommodating IOL group postoperatively. CONCLUSIONS: There was no clear evidence of near acuity improvement despite statistically significant pilocarpine-induced anterior lens displacement. Further randomized controlled studies with standardized methods evaluating adverse effects (eg, PCO) are needed to clarify the tradeoffs.

Neuroadaptation of presbyopia-correcting intraocular lenses.

PURPOSE OF REVIEW: Advances in the design of intraocular lenses give options to patients for some return to the optical accommodation needed to focus on objects at different distances. Technology is only improving these options for presbyopic-correcting intraocular lenses. Surgeons must consider the possible neuroadaptation abilities in patients that may help in the success of using these lenses. RECENT FINDINGS: The hierarchy of the visual system allows two disparate retinal images to combine to form a single picture with depth. Attempts to correct presbyopia with intraocular lenses add complexity to the pathway with the possible introduction of monovision or intraocular rivalry. The neuroadaptation involved in successful use of these lenses has not been study but has been well established in other neurologic processing. SUMMARY: Understanding what patient selection factors are important for neuroadaptation may contribute to outcome success.

Ocular pathologic findings of neurofibromatosis type 2.

OBJECTIVE: To gain insight into the pathogenesis of neurofibromatosis type 2 (NF2) by investigating the ocular manifestations of this disease. METHODS: Using standard histologic techniques, immunohistochemistry, and electron microscopy, we described the ocular pathologic findings of a 34-year-old woman who died from complications of NF2. RESULTS: We identified 3 types of NF2-associated lesions: juvenile posterior subcapsular cataracts, epiretinal membranes, and an intrascleral schwannoma. CONCLUSIONS: Our analysis indicated that dysplastic lens cells accumulate just anterior to the posterior lens capsule in juvenile posterior subcapsular cataracts and that dysplastic Müller cells may be a major component of NF2-associated epiretinal membranes. Clinical Relevance Our findings suggest that a subset of glial cells with epithelial features (Schwann cells, ependymal cells, and Müller cells) may be particularly sensitive to loss of the NF2 gene. Understanding the molecular basis for this sensitivity may lead to novel strategies for treating NF2.

Anterior visual pathway gliomas: The last 30 years.

Modern neuroimaging provides excellent characterization of anterior visual pathway gliomas, often obviating the need for biopsy of the tumor. Management remains controversial, but if there is progression, chemotherapy is preferred for young patients. Stereotactically guided conformal radiotherapy and proton beam radiotherapy allow smaller, more precise doses of radiation to be administered and can be considered in older children with progressive disease. A mouse model of NF-1 with optic pathway gliomas has the potential to provide important insights into the development of gliomas as well as serving as a model for their effective treatment.