Marsha A. Apushkin

Use of dorzolamide for patients with X-linked retinoschisis.

Purpose: To determine the value of a topical carbonic anhydrase inhibitor for the treatment of foveal lesions in patients with X-linked retinoschisis (XLRS). Methods: Eight patients with XLRS and foveal cystic-appearing spaces by fundus examination and by optical coherence tomography (OCT) were treated with a topical form of carbonic anhydrase inhibitor. Changes in “foveal thickness” and “foveal zone thickness” were measured by OCT, and changes of best-corrected visual acuity were measured by Early Treatment Diabetic Retinopathy Study (ETDRS) charts. Results: Seven of eight patients treated with 2% dorzolamide had a noticeable reduction in foveal thickness as well as cystic-appearing spaces by OCT. This reduction was found in both eyes in four of these patients and in one eye in one patient after 1 month of treatment. After an additional 1 month to 2 months of the same treatment regimen, two additional patients also had a noticeable reduction in foveal thickness as well as cystic-appearing spaces. Of these seven patients who had an improvement shown by OCT with treatment, five also had improvement of their visual acuity by ≥7 letters in at least one eye on ETDRS charts. Conclusion: The present study shows the efficacy of topical dorzolamide for treating foveal cystic-appearing lesions in patients with XLRS.

Continued use of dorzolamide for the treatment of cystoid macular oedema in patients with retinitis pigmentosa

Aim: To determine the value of a topical carbonic anhydrase inhibitor for extended treatment of cystoid macular oedema (CME) in patients with retinitis pigmentosa (RP). Method: Eight patients with RP and foveal cystic-appearing lesions observed on fundus examination and by optical coherence tomography (OCT) testing were treated with a topical form of carbonic anhydrase inhibitor. Results: Foveal cystic-like spaces were documented by OCT testing in all eight patients before treatment. All patients had a significant reduction in their foveal thickness (FT) and foveal zone thickness (FZT) in at least one eye after using 2% dorzolamide three times a day for 1 or 2 months. Six patients had an improvement in both eyes. After an additional 6–13 months of the same treatment regimen, out of six patients who had a sustained reduction in FT and FZT in at least one eye, four had this reduction in both eyes. While they were still taking Trusopt, a recurrence (rebound) of CME in both eyes was observed in two patients, whereas one patient had a sustained improvement in one eye and rebound of CME in the other eye. Out of 8 patients, 3 showed an improvement in their visual acuity by ⩾7 letters, in at least one eye, on Snellen acuity charts, which was determined as clinically significant. Conclusion: Results from this study suggest that patients with RP could potentially sustain a beneficial effect from continued treatment with a topical form of carbonic anhydrase inhibitor.

Rebound Of Cystoid Macular Edema With Continued Use Of Acetazolamide In Patients With Retinitis Pigmentosa

Purpose: To demonstrate the presence of a rebound effect with the use of acetazolamide for the treatment of cystoid macular edema (CME) in patients with retinitis pigmentosa (RP). Methods: Six patients with RP and cystic-appearing lesions in the macula demonstrated by fluorescein angiography and/or optical coherence tomography (OCT) were treated with an oral form of carbonic anhydrase inhibitor (acetazolamide [500 mg]) as a single daily dose. Results: All patients, treated with acetazolamide for a period of 3 weeks to 5 weeks, had initial improvement of macular edema demonstrated by OCT. However, extended use of acetazolamide, for at least 8 weeks to 12 weeks, resulted in recurrence (rebound) of CME in 3 of the 6 patients. Conclusions: Results from our study suggest that rebound of CME with the continued use of acetazolamide observed by OCT may occur more frequently than previously appreciated.

Fundus findings and longitudinal study of visual acuity loss in patients with X-linked retinoschisis.

Purpose: To determine the presence of fundus findings and natural course of visual acuity change in patients with juvenile X-linked retinoschisis (XLRS). Methods: A retrospective longitudinal study of 38 patients with juvenile XLRS (age range, 9–65 years) was conducted. Best-corrected visual acuity, Goldmann visual fields, and results of slit-lamp biomicroscopy of the anterior segment and dilated fundus examination were obtained for all patients. Visual acuity findings at the most recent and initial visits were compared. Follow-up ranged from 1 year to 28 years (mean, 10.2 years). Twenty-five patients were observed for >5 years, and 11, for ≥15 years. Results: Foveal lesions varied from predominantly radial striations (3%), microcystic lesions (34%), honeycomblike cysts (8%), or their combinations (31%) to non–cystic-appearing foveal changes, such as pigment mottling (8%), loss of the foveal reflex (8%), or an atrophic-appearing lesion (8%). Twelve patients (32%) had situs inversus of their retinal vessels. We observed a superior nasal restriction in the peripheral visual field even in the absence of clinically apparent peripheral retinoschisis. Of the 38 patients who were seen more than once, using logarithm of the minimum angle of resolution (logMAR) comparison, 4 had a decrease in visual acuity of >0.1 logMAR, equivalent to >1 line on an ETDRS chart, in their better seeing eye, and 3 had a reduction in visual acuity of >0.2 logMAR in their better eye. Conclusions: A limited change in visual acuity was observed in our cohort of 38 patients with XLRS even over an extended period. However, those patients with non–cystic-appearing changes within the fovea, including pigment mottling or an atrophic-appearing lesion, tended to have a more appreciable degree of visual acuity impairment compared with those patients with a cystic-appearing foveal change.

Improvement in visual function and fundus findings for a patient with vitamin A-deficient retinopathy.

Primarily because of dietary deficiency in poor populations, vitamin A deficiency and its accompanying ocular changes are unfortunately quite common in the developing world. In the West, this deficiency can often result primarily from instances of alimentary malabsorption. Although visual function has previously been demonstrated to improve after the treatment of patients with vitamin A deficiency, limited information is available in the recent literature on the alteration of fundus findings for such patients.1–7 We describe a patient with retinopathy secondary to vitamin A deficiency whose fundus condition improved with treatment.

Retinal thickness and visual thresholds measured in patients with retinitis pigmentosa.

Purpose: To determine the association between retinal thickness and visual function in patients with retinitis pigmentosa (RP). Methods: Retinal thickness was estimated from optical coherence tomography (OCT) images obtained for six patients with RP. The thickness measurements were compared with dark-adapted rod and minimally light-adapted cone thresholds obtained by psychophysical testing using a Tübinger perimeter and with standard light-adapted Humphrey visual field (HVF) perimetric thresholds. Results: Four patterns of association between retinal thickness and visual function were observed: normal retinal thickness and normal visual thresholds; normal retinal thickness and normal cone thresholds but elevated rod thresholds; reduced retinal thickness and elevated rod and cone thresholds; and normal retinal thickness and normal Humphrey thresholds but elevated rod and cone thresholds by Tübinger perimetry. Conclusion: Retinal thinning was observed only when both rod and cone thresholds were elevated. However, normal retinal thickness was not necessarily accompanied by normal visual sensitivity. The determination of retinal thickness by OCT and its association with psychophysical measurements of visual function could be useful for identifying those RP patients who might respond most optimally to therapeutic interventions.