Ira H. Schachar

Diagnostic Fundus Autofluorescence Patterns in Achromatopsia

PURPOSE To describe the unique diagnostic fundus autofluorescence (FAF) patterns in patients with achromatopsia and the associated findings on optical coherence tomography (OCT). DESIGN Observational case series. METHODS We evaluated 10 patients with achromatopsia by means of best-corrected visual acuity (BCVA), ophthalmoscopy, Goldmann visual field, full-field electroretinography (ffERG), OCT, and FAF photography. FAF patterns were compared with patient age and foveal changes on OCT. RESULTS Patients fell into two dichotomous age groups at the time of evaluation: six patients ranged from 11 to 23 years of age, and 3 patients ranged from 52 to 63 years of age. All patients had severely reduced photopic ffERG responses, including those exhibiting preserved foveal structure on OCT. The younger patients had absent to mild foveal atrophy on OCT, and four of the six demonstrated foveal and parafoveal hyperfluorescence on FAF. In addition, a 7-month-old child with compound heterozygous mutations in CNGA3 demonstrated similar foveal hyperfluorescence. The older patients demonstrated advanced foveal atrophy and punched-out foveal hypofluorescence with discrete borders on FAF imaging corresponding to the area of outer retinal cavitation on OCT. CONCLUSIONS Foveal hyperfluorescence is an early sign of achromatopsia that can aid in clinical diagnosis. In our cohort, patients with achromatopsia demonstrated age-dependent changes in FAF, which are likely to be progressive and to correlate with foveal atrophy and cavitation on OCT. This finding may be useful in charting the natural course of the disease and in defining a therapeutic window for treatment.

Autofluorescence quantification of benign and malignant choroidal nevomelanocytic tumors.

IMPORTANCE Accurate diagnosis of choroidal melanoma is challenging and has important implications for both physicians and patients. We assessed the utility of quantification of fundus autofluorescence in the evaluation and follow-up of choroidal nevomelanocytic tumors. OBJECTIVE To assess the utility of autofluorescence quantification in distinguishing clinically diagnosed choroidal nevi, melanoma, and indeterminate nevomelanocytic lesions. DESIGN, SETTING, AND PARTICIPANTS A retrospective observational study from 2006 to 2012 of patients with choroidal nevomelanocytic lesions who had digital autofluorescence and color fundus imaging performed at the University of Michigan Kellogg Eye Center. INTERVENTION ImageJ software was used to output autofluorescence gray-scale values for each pixel of a 500 × 50-pixel region within each lesion and a corresponding adjacent control region. MAIN OUTCOME AND MEASURE A single value was generated, termed the Index of Retinal Autofluorescence (IRA), to represent the total difference in gray-scale values between the 2 regions in each affected eye. RESULTS Thirteen of the 14 clinically diagnosed nevi exhibited an IRA less than 150 gray-scale intensity squared (gsi2). Eight of 9 clinically diagnosed melanomas exhibited an IRA more than 150 gsi2. An IRA of 150 gsi2 distinguished nevi from melanomas with a sensitivity of 0.89 and specificity of 0.93. Fifteen of 19 patients with indeterminate nevomelanocytic lesions underwent clinical assessment and initial imaging with clinical follow-up at a median of 10 months. All 3 patients with an IRA less than 150 gsi2 showed no evidence of clinical progression and 6 of 12 lesions with an IRA more than 150 gsi2 showed clinical progression to melanoma. An IRA of 150 gsi2 identifies indeterminate lesions that progressed to melanoma with a sensitivity of 1.00 and specificity of 0.33. CONCLUSIONS AND RELEVANCE Quantification of digital autofluorescence images can differentiate between clinically benign and malignant choroidal nevomelanocytic lesions and may be predictive for clinical progression of indeterminate lesions.

Outcomes of Intravitreal Bevacizumab and Diode Laser Photocoagulation for Treatment-Warranted Retinopathy of Prematurity

BACKGROUND AND OBJECTIVE To investigate the outcomes of infants with treatment-warranted retinopathy of prematurity (TW-ROP) who received intravitreal bevacizumab (Avastin; Genentech, South San Francisco, CA) (IVB) injections as compared to diode laser photocoagulation (DLP). PATIENTS AND METHODS Data from the Stanford University Network for Diagnosis of Retinopathy of Prematurity database and inpatients at Stanford Childrens Hospital were retrospectively reviewed for premature newborns with TW-ROP treated with DLP or 0.625 mg of IVB. Patient characteristics, hospital course, and neurodevelopmental outcomes were compared. RESULTS In all, 49 eyes from 25 patients were included; 10 infants (20 eyes) received DLP and 15 infants (29 eyes) received IVB. The IVB infants had significantly fewer diagnoses at the time of discharge and fewer readmissions after initial hospital discharge than the DLP infants (four versus six diagnoses, P = .004; zero versus one readmission, P = .038). At an average of 20 months corrected age, there was no significant difference in neurodevelopmental delay (adjusted odds ratio = 0.87; 95% CI, 0.08-9.46). CONCLUSION Systemic morbidity may be similar among infants treated initially with bevacizumab compared to DLP. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:126-131.].

Image registration reveals central lens thickness minimally increases during accommodation

Purpose To evaluate anterior chamber depth, central crystalline lens thickness and lens curvature during accommodation. Setting California Retina Associates, El Centro, CA, USA. Design Healthy volunteer, prospective, clinical research swept-source optical coherence biometric image registration study of accommodation. Methods Ten subjects (4 females and 6 males) with an average age of 22.5 years (range: 20–26 years) participated in the study. A 45° beam splitter attached to a Zeiss IOLMaster 700 (Carl Zeiss Meditec Inc., Jena, Germany) biometer enabled simultaneous imaging of the cornea, anterior chamber, entire central crystalline lens and fovea in the dilated right eyes of subjects before, and during focus on a target 11 cm from the cornea. Images with superimposable foveal images, obtained before and during accommodation, that met all of the predetermined alignment criteria were selected for comparison. This registration requirement assured that changes in anterior chamber depth and central lens thickness could be accurately and reliably measured. The lens radii of curvatures were measured with a pixel stick circle. Results Images from only 3 of 10 subjects met the predetermined criteria for registration. Mean anterior chamber depth decreased, −67 μm (range: −0.40 to −110 μm), and mean central lens thickness increased, 117 μm (range: 100–130 μm). The lens surfaces steepened, anterior greater than posterior, while the lens, itself, did not move or shift its position as appeared from the lack of movement of the lens nucleus, during 7.8 diopters of accommodation, (range: 6.6–9.7 diopters). Conclusion Image registration, with stable invariant references for image correspondence, reveals that during accommodation a large increase in lens surface curvatures is associated with only a small increase in central lens thickness and no change in lens position.

Importance of Accommodation and Eye Dominance for Measuring Objective Refractions

WE WERE INTERESTED IN THE STUDY BY TSUNEYOSHI AND associates that assessed the difference between objectively measured refraction from 2 different instruments, 1 with monocular closed-field (Nidek ARK-730A) and the other with binocular open-field viewing (Grand Seiko WAM5500) in 29 subjects aged 25–60 years. The authors found the spherical equivalent (SE) refractions were significantly more hyperopic using the Grand Seiko open-field, measured binocularly, when compared with the Nidek closed-field, measured monocularly. The difference was 0.516 0.33 diopter (D). It should be noted that the Nidek is a monocular autorefractor and although the Grand Seiko is a binocular autorefractor, monocular refractions are possible by patching one of the eyes. The question is which of the variables was responsible for the authors’ findings: (1) a difference in the accuracy of the measurements obtained from the 2 autorefactors, (2) the viewing conditions (open vs closed), or (3) binocular vs monocular viewing. Insight can be obtained from a review of the study by Gwiazda and Weber. They compared refractive data, obtained by monocular viewing, from 2 objective, openfield autorefractors (Grand Seiko 52100K and Canon R1) in 50 subjects aged 17–59 years. They then compared these results to data, obtained by monocular viewing, from an objective, closed-field autorefractor (Nidek ARK 700-A) in the same subjects. Their study eliminates 1 of the confounding variables, binocularity. They found that during monocular open-field viewing, the mean SE of the refractions obtained with the Grand Seiko and Canon were 0.65 6 0.06 D (P < .0001) and 0.22 6 0.06 D (P 1⁄4 .001) more hyperopic than those obtained by monocular, closed-field viewing using the Nidek. Moreover, the 2 open-field instruments provided significantly different refractions, 0.436 0.04 D (P < .0001), more hyperopic with the Grand Seiko than with the Canon. The Gwiazda and Weber study demonstrates that under identical monocular testing conditions, the instruments can be responsible for the difference in refraction that was measured. While eliminating the confounding variable of binocularity, they also found that openvs closed-field viewing was itself associated with statistically different refractive measurements. Tsuneyoshi and associates’ findings are, unfortunately, mired in a study design in which the above-noted variables

Automatic Instrument Tracking Endo-Illuminator for Intra-Ocular Surgeries

Vitreoretinal surgery encompasses intraocular surgical procedures performed in the posterior segment of the eye where instruments are inserted into the vitreous cavity to treat vision threatening diseases [1]. This surgery requires highly skilled surgeons to visually inspect and differentiate normal anatomy of the retina from pathology and manipulate retinal tissue with microsurgical instruments (Fig.1). Because the retina is on average 250 m in thickness and retinal anatomical detail is microscopic, adequate illumination for a clear view of the retina during surgery is extremely crucial [1]. However, the current illumination solutions available require surgeons to devote one working hand to achieving suitable illumination.

Maximum human objectively measured pharmacologically stimulated accommodative amplitude

Purpose To measure the maximum, objectively measured, accommodative amplitude, produced by pharmacologic stimulation. Methods Thirty-seven healthy subjects were enrolled, with a mean age of 20.2±1.1 years, corrected visual acuity of 20/20, and mean spherical equivalent refraction (SER) =-0.83±1.60 diopters. For each subject, the right pupil was dilated with phenylephrine 10%. After 30 minutes, the pupil was measured, the left eye was patched, and the right eye was autorefracted. Pilocarpine 4% was then instilled in the right eye, followed by phenylephrine. At 45 minutes after the pilocarpine, autorefraction and pupil size were again measured. Results Mean pupil size pre- and postpilocarpine was 8.0±0.8 mm and 4.4±1.9 mm, respectively. Pre- and postpilocarpine, the mean SER was -0.83±1.60 and -10.55±4.26 diopters, respectively. The mean pilocarpine-induced accommodative amplitude was 9.73±3.64 diopters. Five subjects had accommodative amplitudes ≥14.00 diopters. Accommodative amplitude was not significantly related to baseline SER (p-value =0.24), pre- or postpilocarpine pupil size (p-values =0.13 and 0.74), or change in pupil size (p-value =0.37). Iris color did not statistically significantly affect accommodative amplitude (p-value =0.83). Conclusion Following topically applied pilocarpine, the induced objectively measured accommodation in the young eye is greater than or equal to the reported subjectively measured voluntary maximum accommodative amplitude.