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PURPOSE To evaluate dark-adapted retinal sensitivity in patients with Stargardt disease (STGD1) using a modified MP-1 microperimeter and to compare the sensitivity loss with structural changes observed using spectral domain optical coherence tomography and confocal scanning laser ophthalmoscope infrared imaging. METHODS Twelve STGD1 patients and 10 normally sighted controls participated. Dark-adapted mean sensitivity (MS) was obtained using a MP-1 microperimeter. Additionally, MS percent difference between the patients and the controls was obtained. Sensitivity results were superimposed on confocal scanning laser ophthalmoscope infrared images and compared with corresponding spectral domain optical coherence tomography scans. RESULTS Dark-adapted MS ± standard deviation was 8.34 ± 1.54 dB for the controls and 3.68 ± 1.74 dB for STGD1 patients (P < 0.001). There was a significant reduction in MS of 24.0% in these patients. Sensitivity reductions were observed in areas that showed changes on confocal scanning laser ophthalmoscope infrared images and on spectral domain optical coherence tomography, including disorganizational loss of the retinal pigment epithelium, and abnormal photoreceptor inner segment ellipsoid and external limiting membrane reflectance bands. CONCLUSION With topographical accuracy, dark-adapted MS measurements can be made in STGD1 patients and controls using the MP-1 microperimeter. Sensitivity loss is associated with structural changes. This finding can be useful for the determination of optimal areas for potential improvement of retinal function in patients with Stargardt disease.

Cystic macular lesions frequently contribute to impaired visual acuity in hereditary retinal dystrophies. Their pathogenesis varies and is not entirely understood. Carbonic anhydrase inhibitors have proven to be potentially efficacious, although not in all cases. We discuss the various factors and mechanisms implicated in the etiology of cystic macular lesions (anatomical abnormalities, impairment of the blood-retinal barrier, tangential vitreous traction, and mutations in retinoschin, etc.) and the various treatments that have been proposed.

The purpose of this study was to measure macular sensitivity using microperimetry in patients on Plaquenil therapy without evidence of retinopathy as assessed by recommended screening standards. Sixteen patients from a clinical practice treated with 200 or 400 mg/day of Plaquenil for more than 5 years, without visual complaints (visual acuity 20/25 or better), and without a history of diabetes or macular disease were included. Participants underwent a complete ophthalmic examination with spectral-domain optical coherence tomography (SD-OCT), 10-2 Humphrey visual field (HVF), fundus autofluoresecene (FAF), multifocal electroretinography (mfERG), and microperimetry that covered the central 12° of the visual field. Ten age-similar, visually normal subjects served as controls. The average age of the study cohort was of 54.5 years, with an average daily Plaquenil dose of 4.00 mg/kg/day (range, 1.77–6.67 mg/kg/day) and an average cumulative dose of 1485 g (range, 256–3650 g). All patients had normal ocular exams, and no evidence of retinopathy based on 10-2 HVF, FAF, mfERG, and SD-OCT. The mean retinal sensitivity by microperimetry was 15.0 dB (OD) and 14.6 dB (OS). The overall mean microperimetry sensitivity of the patients (14.7±1.9 dB) was significantly lower (P

To determine the prevalence of macular cysts in patients with clinical cone-rod dystrophy (CORD) using spectral-domain optical coherence tomography (SD-OCT). If macular cysts could be demonstrated in such patients, they might benefit from treatment with a carbonic anhydrase inhibitor that has been shown to be effective for treating macular cysts in various night-blinding disorders.Thirty-six CORD patients underwent a complete ophthalmic examination and an SD-OCT examination using two different systems. The presence of hypo-reflective lacunae was used to determine the presence of macular cysts.The patients' mean age was 42.9 ± 19.5 years (range 6-71 years). Mean BCVA was 1.09 ± 0.64 logMAR (range no light perception to 20/25 + 2 in the better-seeing eye). All the 72 eyes studied showed a variable degree of retinal thinning, disruption of what has been referred to as the inner segment ellipsoid and outer nuclear layer (ONL) thinning of the macula. None showed evidence of macular cysts on OCT testing.Although macular cysts are a common feature of various hereditary night-blinding retinal dystrophies, these were not identified in our cohort of CORD patients.

PURPOSE To measure the peripapillary retinal nerve fiber layer (RNFL) thickness using spectral-domain optical coherence tomography in patients with retinitis pigmentosa. METHODS Fifty eyes of 30 patients with retinitis pigmentosa underwent a complete ocular examination, including best-corrected visual acuity using a Snellen chart, slit-lamp biomicroscopic examination, and Goldmann applanation intraocular pressure measurement. Dilated fundus examination was performed using both direct and indirect ophthalmoscopy. In addition, all patients underwent peripapillary RNFL thickness measurements using an OPKO spectral-domain optical coherence tomography (OPKO Instrumentations, Miami, FL). RESULTS The mean (± SD) age of the study cohort was 45.8 (± 16.3) years. Of the 50 eyes, 18 (36%) showed a thinning of the peripapillary RNFL in 1 or more quadrants and 21 (42%) showed a thickening of the peripapillary RNFL in 1 or more quadrants. Four eyes (8%) showed both thinning and thickening of the peripapillary RNFL thickness. The overall circumferential RNFL thickness of the 14 eyes that showed only thinning in at least 1 quadrant was 78.78 μm. For the 17 eyes that showed only thickening in at least 1 quadrant, the RNFL thickness was 119.69 μm. The values of the eyes with thinning and the eyes with thickening were significantly different from normal (t = 6.31 and P < 0.01 for thickening; t = 3.62 and P < 0.01 for thinning). CONCLUSION Using spectral-domain optical coherence tomography testing, we demonstrated in the current study that the peripapillary RNFL thickness in patients with RP can be decreased, increased, or maintained within normal limits. Assessment of the RNFL thickness seems prudent in these patients, particularly for identifying notable degrees of RNFL thinning in those being considered for future therapeutic trials.

Purpose To correlate the degree of functional loss with structural changes in patients with Stargardt disease. Methods Eighteen eyes of 10 patients with Stargardt disease were studied. Scanning laser ophthalmoscope infrared images were compared with corresponding spectral-domain optical coherence tomography scans. Additionally, scanning laser ophthalmoscope microperimetry was performed, and results were superimposed on scanning laser ophthalmoscope infrared images and in selected cases on fundus autofluorescence images. Results Seventeen of 18 eyes showed a distinct hyporeflective foveal and/or perifoveal area with distinct borders on scanning laser ophthalmoscope infrared images, which was less evident on funduscopy and incompletely depicted in fundus autofluorescence images. This hyporeflective zone corresponded to areas of significantly elevated psychophysical thresholds on microperimetry testing, in addition to thinning of the retinal pigment epithelium and disorganization or loss of the photoreceptor cell inner segment-outer segment junction and external-limiting membrane on spectral-domain optical coherence tomography. Conclusion Scanning laser ophthalmoscope infrared fundus images are useful for depicting retinal structural changes in patients with Stargardt disease. A spectral-domain optical coherence tomography/scanning laser ophthalmoscope microperimetry device allows for a direct correlation of structural abnormalities with functional defects that will likely be applicable for the determination of retinal areas for potential improvement of retinal function in these patients during future clinical trials and for the monitoring of the diseases' natural history.

To evaluate the presence of peripapillary retinal nerve fiber layer (RNFL) defects in patients with choroideremia by using spectral-domain optical coherence tomography (SD-OCT).Twenty-nine eyes of 16 patients with choroideremia underwent peripapillary RNFL thickness measurements by using SD-OCT.The mean (±SD) age of the study population was 44.0 ± 16.0 years (range, 13-63 years). Thirteen eyes (45%) showed a thinning of the peripapillary RNFL in at least 1 quadrant in either 1 or both eyes. Thinning was most commonly found in the superior (13 eyes) and inferior (10 eyes) quadrants. Twenty-one eyes (72%) showed a thickening of the peripapillary RNFL in at least 1 quadrant in either 1 or both eyes. Of these 21 eyes, all had thickening in the temporal quadrant. Additionally, 2 eyes in each of the other 3 quadrants were found to be abnormally thick.Our study demonstrated the presence of defects in the peripapillary RNFL thickness in patients with choroideremia by using SD-OCT. It would be clinically prudent that choroideremia patients considered for various treatment options be considered for RNFL thickness measurements.

Purpose: The purpose of this study was to identify the functional and structural characteristics in three female obligate carriers of X-linked retinitis pigmentosa from the same family by using spectral domain optical coherence tomography, fundus autofluorescence, and microperimetry. Methods: Three female obligate carriers with a tapetal-like reflex, 21, 49, and 57 years of age, from a single family of X-linked retinitis pigmentosa that was seen in the ophthalmology department at the University of Illinois at Chicago, were enrolled in the study. All carriers underwent a complete ophthalmic examination. Spectral domain optical coherence tomography measurements, a macular microperimetry examination, and fundus autofluorescence testing were performed. Results: The spectral domain optical coherence tomography examination in all three carriers showed a normal retinal microstructure and thickness. Microperimeter testing showed subnormal retinal sensitivity in the areas of the tapetal-like reflex. Fundus autofluorescence examination showed the presence of speckled areas of enhanced autofluorescence. Conclusion: Our study demonstrates that the carriers of X-linked retinitis pigmentosa with a tapetal-like reflex can show an enhanced reflectance on infrared images, abnormal autofluorescence properties, elevated retinal thresholds, and a normal retinal morphology within the posterior pole on spectral domain optical coherence tomography testing.

Aims To evaluate the presence of peripapillary retinal nerve fibre layer (RNFL) defects in patients with Stargardt disease by using spectral-domain optical coherence tomography (SD-OCT). Methods Fifty-two eyes of 27 patients with Stargardt disease underwent peripapillary RNFL thickness measurements using SD-OCT. Results Twenty-seven patients with Stargardt disease were enrolled. Their mean (±SD) age was 38.3 (14.7) years. Fourteen patients (51.9%) showed a thinning of the peripapillary RNFL in one or more quadrants in at least one eye, and four patients (14.8%) in both eyes. Five patients (18.5%) showed a thickening of the peripapillary RNFL in at least one eye, and four patients (14.8%) in both eyes. Conclusion This study demonstrated the presence of defects in the peripapillary RNFL thickness in patients with Stargardt disease by using SD-OCT. It would be clinically prudent that Stargardt patients considered for various treatment options be considered for RNFL thickness measurements.

The purpose of this study was to evaluate the efficacy of topical dorzolamide 2% eye drops on macular function and thickness in a case of enhanced S-cone syndrome (ESCS). A 24-year-old Asian man with enhanced S-cone syndrome treated with topical dorzolamide in the left eye participated in the study. Examinations performed before and during treatment included: visual acuity (VA), contrast sensitivity measured with briefly presented grating targets (grating CS) and the Pelli-Robson chart (P-R CS), microperimetry (MP), and spectral-domain optical coherence tomography (SD-OCT). Following four months of treatment, the mean thickness of the central 1-mm foveal subfield of the left eye, as measured by SD-OCT, decreased from 551 μm to 242 μm. Mean MP sensitivity within the central 12 degrees (28 points) increased from 9.4 dB at baseline to 11.2 dB. Although, Pelli-Robson contrast sensivity improved only minimally in the left eye, grating contrast sensivity improved by more than a factor of two. Mean log MAR VA was 0.22 OD and 1.00 OS (at baseline), which improved to 0.10 OD and 0.66 OS after four months of treatment. The results indicate that in our patient with enhanced S-cone syndrome, treatment with topical dorzolamide was effective in improving macular thickness, VA, microperimetry sensitivity, and grating contrast sensivity. These measures of retinal structure and function are sensitive tools for evaluating the effects of treatment in enhanced S-cone syndrome patients with cystoid macular edema. Further investigation is warranted to assess the relationships among visual performance for daily activities, visual sensitivity, and macular thickness.

Purpose: Fundus albipunctatus is a form of congenital stationary night blindness characterized by an early onset and nonprogressive impairment of night vision and the presence of numerous dull-white punctate lesions scattered throughout the fundus, while retinitis punctata albescens patients often show similar fundus changes but manifest a severe and progressive hereditary retinal dystrophy.Conclusions: In this study, we report the optical coherence tomography and fundus autofluorescence measurements in patients with these hereditary night blinding diseases.

To report a successfully treated case of acquired night blindness associated with fundus white spots secondary to vitamin A deficiency. An ocular examination, electrophysiologic testing, as well as visual field and OCT examinations were obtained on a 61-year-old man with vitamin A deficiency who had previously undergone gastric bypass surgery. The patient had a re-evaluation after treatment with high doses of oral vitamin A. The patient was observed to have numerous white spots in the retina of each eye. Best-corrected visual acuity was initially 20/80 in each eye, which improved to 20/40-1 OU after oral vitamin A therapy for 2 months. Full field electroretinogram (ERG) testing, showed non-detectable rod function and a 34 and 41% reduction for 32-Hz flicker and single flash cone responses, respectively, below the lower limits of normal. Both rod and cone functions markedly improved after initiation of vitamin A therapy. Vitamin A deficiency needs to be considered in a patient with white spots of the retina in the presence of poor night vision.

X-linked retinoschisis (XLRS) is an early-onset hereditary retinal dystrophy. This disease is caused by mutation(s) of the RS1 gene, which encodes for a protein (retinoschisin) that binds to the external membrane of photoreceptor and bipolar cells and plays a role in the structural integrity of the retinal layers. 1 In the first few decades of life cysticappearing (schitic) lesions are found in the macula, and central visual acuity is decreased. Clinically detectable peripheral retinoschisis, most commonly observed bilaterally in the inferior-temporal retina, is often found in XLRS. Subclinical extramacular cystoid spaces were observed on spectral-domain optical coherence tomography (SD-OCT) in 5 of 11 eyes of XLRS patients in one study. 2 Carbonic anhydrase inhibitors have been found to reduce the macular intraretinal cystoid spaces in a notable number of XLRS patients. 3 In this current report, we present a patient diagnosed with XLRS with intraretinal cystoid spaces in the macula and extending to the midperipheral retina. With the use of topical dorzolamide 2%, the intraretinal cystoid spaces resolved from the macula out to the mid-peripheral retina. To our knowledge, the resolution of mid-peripheral retinal cystoid spaces with the use of a carbonic anhydrase inhibitor has not been previously reported.

To evaluate retinal structure and photoreceptor mosaic integrity in subjects with OPN1LW and OPN1MW mutations.Eleven subjects were recruited, eight of whom have been previously described. Cone and rod density was measured using images of the photoreceptor mosaic obtained from an adaptive optics scanning light ophthalmoscope (AOSLO). Total retinal thickness, inner retinal thickness, and outer nuclear layer plus Henle fiber layer (ONL+HFL) thickness were measured using cross-sectional spectral-domain optical coherence tomography (SD-OCT) images. Molecular genetic analyses were performed to characterize the OPN1LW/OPN1MW gene array.While disruptions in retinal lamination and cone mosaic structure were observed in all subjects, genotype-specific differences were also observed. For example, subjects with "L/M interchange" mutations resulting from intermixing of ancestral OPN1LW and OPN1MW genes had significant residual cone structure in the parafovea (∼25% of normal), despite widespread retinal disruption that included a large foveal lesion and thinning of the parafoveal inner retina. These subjects also reported a later-onset, progressive loss of visual function. In contrast, subjects with the C203R missense mutation presented with congenital blue cone monochromacy, with retinal lamination defects being restricted to the ONL+HFL and the degree of residual cone structure (8% of normal) being consistent with that expected for the S-cone submosaic.The photoreceptor phenotype associated with OPN1LW and OPN1MW mutations is highly variable. These findings have implications for the potential restoration of visual function in subjects with opsin mutations. Our study highlights the importance of high-resolution phenotyping to characterize cellular structure in inherited retinal disease; such information will be critical for selecting patients most likely to respond to therapeutic intervention and for establishing a baseline for evaluating treatment efficacy.

This study aimed to determine whether the properties of the late negative responses (LNRs) of the electroretinogram (ERG) elicited by sawtooth flicker are consistent with the characteristics of the photopic negative response generated by a light pulse (PhNRpulse).ERG recordings were obtained from 10 visually normal individuals and from 6 patients with optic atrophy (OA) in response to 8-Hz rapid-on and rapid-off sawtooth flicker and to brief (4 ms) light pulses. All stimuli were either long wavelength (R), middle wavelength (G), or a combination of equal luminances of long and middle wavelengths (Y) presented on a short-wavelength, rod-saturating adapting field. Amplitudes of LNRs were obtained in response to rapid-on (LNRon) and rapid-off (LNRoff) sawtooth flicker and were also derived from the sum of the ERG waveforms to the two sawtooth phases (LNRadd).For the control subjects, PhNRpulse amplitude varied with stimulus wavelength, being largest in response to a long-wavelength pulse, as expected. However, the amplitudes of LNRon, LNRoff, and LNRadd were not significantly different for R, Y, and G sawtooth flicker. Despite the absence of a chromatic effect, LNRoff and LNRadd amplitudes were significantly smaller in the OA patients than in the controls, similar to the results for the PhNRpulse, implying an inner retinal origin for the LNRoff and LNRadd. However, LNRon amplitudes did not differ significantly between the OA patients and controls, although there was a significant correlation between the LNRon and PhNRpulse for R stimuli.We conclude that LNRoff and LNRadd but not LNRon can be useful measures to assess the integrity of the inner retina that can complement the PhNRpulse.

Purpose To examine retinal structure and changes in photoreceptor intensity after dark adaptation in patients with complete congenital stationary night blindness and Oguchi disease. Design Prospective, observational case series. Methods We recruited 3 patients with complete congenital stationary night blindness caused by mutations in GRM6 , 2 brothers with Oguchi disease caused by mutations in GRK1 , and 1 normal control. Retinal thickness was measured from optical coherence tomography images. Integrity of the rod and cone mosaic was assessed using adaptive optics scanning light ophthalmoscopy. We imaged 5 of the patients after a period of dark adaptation and examined layer reflectivity on optical coherence tomography in a patient with Oguchi disease under light- and dark-adapted conditions. Results Retinal thickness was reduced in the parafoveal region in patients with GRM6 mutations as a result of decreased thickness of the inner retinal layers. All patients had normal photoreceptor density at all locations analyzed. On removal from dark adaptation, the intensity of the rods (but not cones) in the patients with Oguchi disease gradually and significantly increased. In 1 Oguchi disease patient, the outer segment layer contrast on optical coherence tomography was 4-fold higher under dark-adapted versus light-adapted conditions. Conclusions The selective thinning of the inner retinal layers in patients with GRM6 mutations suggests either reduced bipolar or ganglion cell numbers or altered synaptic structure in the inner retina. Our finding that rods, but not cones, change intensity after dark adaptation suggests that fundus changes in Oguchi disease are the result of changes within the rods as opposed to changes at a different retinal locus.

A 46-year-old woman with a vitelliform macular lesion secondary to desferrioxamine retinal toxicity in the right eye was treated with brinzolamide 1% ophthalmic drops three times a day. A spectral-domain optical coherence tomography (SD-OCT) unit was used to monitor any changes in the macular lesion. Two months after starting the eye drops, the SD-OCT showed a notable improvement in the vitelliform macular lesion’s thickness. Six months later, further improvement was noted in the macular lesion thickness on SD-OCT testing in the right eye. Best-corrected visual acuity was initially 1.00 logarithm of the minimum angle of resolution (20/200 on a Snellen acuity chart) in the right eye and 0.14 logarithm of the minimum angle of resolution (20/25 −2 ) in the left eye. After 6 months of treatment, visual acuity was 0.92 (20/200 +1 ) in the right eye and 0.08 (20/25 +1 ) in the left eye. The use of brinzolamide 1% was associated with a marked reduction in a vitelliform macular lesion on SD-OCT testing secondary to desferrioxamine retinal toxicity.

To determine the value of a topical carbonic anhydrase inhibitor on the macular thickness and function in choroideremia patients with cystoid macular edema.: Two choroideremia patients with cystoid macular edema, observed by spectral-domain optical coherence tomography, were treated with a topical form of carbonic anhydrase inhibitor. Examinations performed before and during treatment included best-corrected visual acuity by using the Early Treatment Diabetic Retinopathy Study charts and contrast sensitivity measured with briefly presented grating targets and the Pelli-Robson letter contrast sensitivity chart, microperimetry, and spectral-domain optical coherence tomography.: The 2 choroideremia patients treated with dorzolamide 2% formulation had a noticeable reduction in macular thickness by spectral-domain optical coherence tomography. This reduction was found in both eyes after 2 months of treatment. After an additional 3 months of the same treatment regimen, a more noticeable reduction in macular thickness was observed. The two study patients had improvement of their visual acuity, in at least one eye, on Early Treatment Diabetic Retinopathy Study charts, but no clinically significant changes for the other measures of visual function.: The present study shows the potential efficacy of topical dorzolamide for treating choroideremia patients with cystoid macular edema.

Congenital achromatopsia is a genetically heterogeneous, predominantly autosomal recessive, retinal disorder with a prevalence of approximately 1 in 30,000 in the general population.1 It is characterized by a lack of color discrimination, poor visual acuity, photophobia, pendular nystagmus, and abnormal photopic electroretinographic (ERG) recordings with preservation of the rod-mediated ERG. A prior report by Khan and colleagues2 showed that the rod ERG function can be modestly subnormal. The disease has been categorized into complete and incomplete achromatopsia subtypes. The incomplete (atypical) form is defined as dyschromatopsia, in which the symptoms are similar to those of the complete achromatopsia (typical) form but with less visual dysfunction.3 Patients with the complete form have nondetectable cone function on ERG testing, whereas those with the incomplete form retain some residual cone function on ERG, and often more preserved color vision and a higher level of visual acuity (up to 0.20).3–5 Funduscopy is usually normal in both forms, although not infrequently macular pigmentary mottling and even occasionally atrophic changes have been described.6 The known causes of congenital achromatopsia are all due to malfunction of the retinal phototransduction pathway. Specifically, recessive forms of achromatopsia result from the inability of cone photoreceptors to properly respond to a light stimulus by hyperpolarizing. To date, mutations in four genes have been identified to cause achromatopsia in human patients, including the α- and β-subunits of the cone cyclic nucleotide-gated ion channels, CNGA3 (ACHM2, OMIM600053) and CNGB3 (ACHM3, OMIM605080), which are located in the plasma membrane of the cone outer segments, the α-subunit of the cone photoreceptor transducin, GNAT2 (ACHM4, OMIM139340), and the catalytic α-subunit of the cone cyclic nucleotide phosphodiesterase, PDE6C (OMIM600827). The vast majority of human cases of achromatopsia are caused by mutations in either CNGA3 or CNGB3.7–11 Prior recent reports of animal studies showed that CNGB3, CNGA3, or GNAT2 knockout mice and naturally occurring dog models of achromatopsia responded well to adenoassociated virus (AAV) gene therapy. In animal models of human achromatopsia, cone ERG amplitudes recovered to nearly normal levels.12–14 These results from proof-of-principle experiments in animals with cone-directed gene therapy offer promise for eventual translation to human patients. Identifying and then targeting retinal locations with retained photoreceptors will be a prerequisite for successful gene therapy in achromatopsia patients. Previous observations regarding photoreceptor structure in achromatopsia have been limited primarily to histologic reports. In a previous report by Galezowski,15 the retinal cones were described as entirely absent. Larsen16 reported malformed foveal cones with normal cones in the peripheral retina, whereas Harrison et al.17 found misshaped and reduced numbers of retinal cones. In another report by Falls et al.,18 normal numbers of odd-shaped foveal cones and isolated numbers of cones in the peripheral retina were described. Glickstein and Heath19 found no evidence of foveal cones and reduced numbers of peripheral cones. Although genetic testing was not available at the time of these studies, they nevertheless highlight the fact that the picture of photoreceptor structure in achromatopsia is likely to be complex. Some clarity on this issue has begun to come from the use of noninvasive imaging techniques to assess photoreceptor structure in patients with achromatopsia. Optical coherence tomography (OCT), which provides excellent axial resolution, has been used to show a highly variable phenotype at the level of the photoreceptor inner segment (IS) and outer segment (OS),4,6,20,21 although the general interpretation has been that there is an absence or reduction of healthy cone structure. Adaptive optics (AO) provides high lateral resolution,22–24 and was used in a single case to examine photoreceptor structure on the single-cell level.25 The authors visualized a normal rod photoreceptor mosaic, but did not report any evidence of cone structure. These findings only confirm the complexity of the photoreceptor phenotype in achromatopsia, thus warranting further investigation. Here we used noninvasive high-resolution imaging tools (spectral domain [SD]- OCT and AO scanning laser ophthalmoscopy [SLO]) together with functional measures of vision (ERG, microperimetry [MP], and color vision) to assess photoreceptor structure and function in patients with congenital achromatopsia. We sought to correlate these findings with genetic information from the same subjects. Not only is this approach expected to provide a better understanding of the disease, but also should prove useful in identifying which patients may be most likely to benefit from participating in future gene-targeted treatment trials to rescue or restore cone photoreceptors in this group of patients. Moreover, the structural and functional assays used here would be useful for evaluating the therapeutic efficacy in patients who in fact go on to receive intervention.

To determine the prevalence of cystic macular oedema (CME) in patients with choroideremia (CHM) by using spectral-domain optical coherence tomography (SD-OCT). A total 16 patients affected with CHM were enroled in the study. All patients underwent a complete eye examination. SD-OCT was performed using an OPKO spectral-domain OCT/SLO instrument. The average age of the study patients was 44.0±16.0 years (range, 13–63 years). Out of the 16 patients with CHM, 10 patients (62.5%) showed a degree of CME on SD-OCT testing in at least one eye, and 8 patients (50%) showed CME in both eyes. Because of its notable prevalence, it would seem prudent to screen CHM patients by SD-OCT for the possible presence of CME and to identify those amenable to future treatment strategies for their macular oedema.

Objective To determine the efficacy of sustained topical therapy with dorzolamide hydrochloride, 2%, on visual acuity and cystic macular lesions in patients with retinitis pigmentosa and Usher syndrome. Methods In a retrospective case series at a university hospital, 64 eyes of 32 patients with retinitis pigmentosa or Usher syndrome receiving treatment with the topical dorzolamide formulation for 6 to 58 months were enrolled. Changes in visual acuity on the Early Treatment Diabetic Retinopathy Study chart and central foveal zone thickness on optical coherence tomography were measured during follow-up for the duration of treatment. Results Among the study cohort, 20 of 32 patients (63%) showed a positive response to treatment in at least 1 eye and 13 patients (41%) showed a positive response in both eyes. Four patients (20%) showed an initial response and a subsequent rebound of macular cysts. In 8 patients (25%), there was no response to treatment and the macular cysts worsened when compared with the pretreatment level. Ten patients (31%) had improvement in visual acuity by 7 or more letters in at least 1 eye at the most recent follow-up visit. Sixteen patients (67%) showed a reduction of more than 11% in the central foveal zone thickness in at least 1 eye when compared with the pretreatment level. Conclusions Patients with either retinitis pigmentosa or Usher syndrome who received treatment of cystoid macular edema with topical dorzolamide followed by an optical coherence tomography–guided strategy showed a decrease in central foveal zone thickness in most cases. Visual acuity improved in almost one-third of the cases, suggesting a potential corresponding visual benefit.

To determine the efficacy of sustained topical therapy with dorzolamide hydrochloride, 2%, on visual acuity and cystic macular lesions in patients with juvenile X-linked retinoschisis (XLRS).Retrospective analysis.University hospital, tertiary care referral center.Twenty-nine eyes of 15 patients with XLRS receiving treatment with the topical dorzolamide formulation for 4 to 41 months were enrolled.Changes in visual acuity, cystic macular lesions, and central foveal zone thickness on optical coherence tomography during follow-up for the duration of treatment.Among the 15 patients with XLRS, 20 eyes (69%) of 11 patients showed a positive response to treatment. Five of the 20 eyes (25%) in 3 of the 11 patients showed an initial response and a subsequent rebound of macular cysts. In 4 eyes (14%) of 3 patients, there was no response to treatment, but the macular cysts did not worsen compared with the baseline level. In 5 additional eyes (17%) of 4 patients, there was no response to treatment, and the macular cysts worsened when compared with the baseline level. Sixteen eyes (55%) of 12 patients had improvement in best-corrected visual acuity by at least 7 letters in at least 1 eye at the most recent follow-up visit. Seventeen eyes (59%) of 10 patients showed a reduction in the central foveal zone thickness in at least 1 eye when compared with the pretreatment level.Patients with XLRS have the potential to experience a beneficial effect from sustained treatment with dorzolamide, 2%.

PURPOSE. To determine longitudinal changes in fundus appearance and visual function in patients with Stargardt with at least one allelic mutation (Glyl961Glu) in the ABCA4 gene. METHODS. Sixteen patients with a diagnosis of Stargardt disease and a Gly1961Glu mutation were enrolled. All patients underwent a complete ocular examination including best corrected visual acuity, Goldmann visual field (GVF), and full-field ERG examinations. The percentage of patients who showed at least a doubling in the log of the minimum angle of visual resolution (logMAR) between their initial and most recent visits was determined, as was the percentage of patients who showed a doubling in the size of the central scotoma over this duration. RESULTS. Nine patients had at least a doubling of the logMAR visual acuity in their right eyes and 10 patients in their left eyes, over a mean follow-up (FU) period of 18.6 years. Of 15 patients, 46.7% had equal to or more than a doubling of the central scotoma area in response to a II2e test stimulus in the right eye and 60.0% in the left eyes. Among 10 patients whose ERGs were initially normal for rod and cone responses, 8 remained normal at their most recent FU visit. CONCLUSIONS. In these patients with Stargardt disease and a Gly1961Glu mutation, most showed a clinical phenotype characterized by fundus changes localized to the foveal and parafoveal regions, normal ERG amplitudes, absence of a silent or masked choroid, and a mean age at initial presentation in the third decade.

PURPOSE: To determine the relationships among equivalent intrinsic noise (Neq), sampling efficiency, and contrast sensitivity (CS) in patients with retinitis pigmentosa (RP), where Neq is an estimate of the amount of noise within the visual pathway and sampling efficiency represents the subject's ability to use stimulus information optimally. METHODS: Participants included 10 patients with RP aged 10 to 54 years, who had visual acuities of 20/40 or better, and 10 visually normal control subjects aged 22 to 65 years. CS was measured for 2-cycles-per-degree Gabor patch targets presented in the absence of noise (CS0) and in five levels of noise spectral density. Data were fit with a standard linear amplifier model, which provided estimates of Neq and sampling efficiency. RESULTS: CS0 for the patients ranged from normal to as much as a factor of 3 below the lower limit of normal. All 10 patients had abnormally high Neq, including two patients with normal CS0. In comparison, only two patients had lower-than-normal sampling efficiency, and these two patients also had below-normal CS0. Log CS0 for the patients was correlated significantly with log Neq (r = -0.80, P < 0.05), but not with log efficiency (r = 0.54, P = 0.11). CONCLUSIONS: Low CS was associated with elevated intrinsic noise in this group of RP patients, but even patients with normal CS had elevated noise levels. The results suggest that CS measurement in both the presence and absence of luminance noise can provide important information about visual dysfunction in RP patients.