Serena Salvatore

Treatment of cystic macular lesions in hereditary retinal dystrophies

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.

Endothelin-1 Role in Human Eye: A Review

Endothelin is a potent vasoactive peptide occurring in three isotypes, ET-1, ET-2, and ET-3. Through its two main receptors, endothelin A and endothelin B, it is responsible for a variety of physiological functions, primarily blood flow control. Recent evidence from both human and animal models shows involvement of endothelin in diabetes, retinal circulation, and optic neuropathies. Increased circulating levels of endothelin-1 (ET-1) have been found in patients with diabetes, and a positive correlation between plasma ET-1 levels and microangiopathy in patients with type-2 diabetes has been demonstrated. In addition to its direct vasoconstrictor effects, enhanced levels of ET-1 may contribute to endothelial dysfunction through inhibitory effects on nitric oxide (NO) production. Experimental studies have shown that chronic ET-1 administration to the optic nerve immediately behind the globe causes neuronal damage, activation of astrocytes, the major glial cell in the anterior optic nerve, and upregulation of endothelin B receptors. This paper outlines the ubiquitous role of endothelin and its potential involvement in ophthalmology.

Association of dark-adapted visual function with retinal structural changes in patients with Stargardt disease.

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.

The Mozart effect in biofeedback visual rehabilitation: a case report.

Purpose To evaluate the usefulness of acoustic biofeedback by means of Mozart’s Sonata for Two Pianos in D Major K. 448 to maintain and/or restore visual performance in a patient with macular pucker and glaucoma. Methods A 74-year-old patient with open angle glaucoma in both eyes and macular pucker in the right eye (RE) underwent visual rehabilitation with acoustic biofeedback by means of the MAIA™ Vision Training Module (Centervue, Padova, Italy) 10 minutes each eye once a week for 5 weeks. The patient was asked to move his eyes according to a sound which changed into Mozart’s Sonata for Two Pianos when the patient locked the fixation target. Results Best-corrected visual acuity improved in his right eye (RE) and was stable in the left eye (LE). Fixation stability improved in both eyes, and retinal sensitivity decreased in the RE and improved in the LE. The characteristic of the macular pucker did not change during the training as demonstrated with optical coherence tomography. The patient was very satisfied with the training, as demonstrated by a 25-item questionnaire (National Eye Institute – Visual Functioning Questionnaire, NEI-VFQ-25). The patient’s reading speed and the character size which he was able to read improved in his RE. Conclusion Music could enhance synaptic plasticity and affect neural learning and fixation training by means of MAIA vision training. Therefore it can improve visual performance in patients with macular pucker, postpone the surgical time, and assure a better quality of life for the patient.

Corneal Sensitivity in Keratoconus: A Review of the Literature

Corneal sensitivity has recently received much attention given the crucial role the corneal nerves play in maintaining normal corneal structure and function. An increased understanding of the corneal sensitivity and dry eye disease in keratoconus, including alterations of the conjunctival cells, may help explain the pathogenesis of this disorder. There is histological evidence of the involvement of corneal nerves in the pathology of keratoconus and it has been suggested that this plays a role in the pathophysiological features and progression of the disease. In this review, the impaired corneal sensitivity found on keratoconus and corneal sensitivity changes after cross-linking performed in patients with keratoconus are reported.

Recovery of corneal sensitivity after collagen crosslinking with and without epithelial debridement in eyes with keratoconus.

Purpose To evaluate the changes in corneal sensitivity after corneal collagen crosslinking (CXL) with the epithelium off (epi‐off) and with the epithelium on (epi‐on) in eyes with keratoconus. Design Prospective interventional case series. Setting Eye Clinic, A. Fiorini Hospital, Terracina (Latina), Rome, Italy. Methods On the basis of the corneal pachymetry at the area of topographic steepening, eyes treated with CXL were divided in 2 groups: those with a corneal thickness of 400 &mgr;m or more (epi‐off) and those with a corneal thickness of less than 400 &mgr;m (epi‐on). Corneal sensitivity was measured using a contact esthesiometer (Cochet‐Bonnet) before treatment and 1 and 7 days and 1, 3, 6, 9, and 12 months after treatment. Results The study evaluated 50 CXL‐treated eyes in 50 patients (25 epi‐on and 25 epi‐off) from January 7, 2012, to December 15, 2012. In the epi‐off group, corneal sensitivity was statistically significantly reduced for up to 3 months after CXL and gradually returned to normal levels. In the epi‐on group, corneal sensitivity was statistically significantly reduced for up to 7 days but was not statistically significantly different from preoperative values at other measurement times. At 7 days, the corneal sensitivity was statistically significantly lower in the epi‐off eyes than in the epi‐on eyes. Conclusions Epi‐off and epi‐on CXL both caused hypoesthesia, but corneal sensitivity subsequently recovered completely. The corneal hypoesthesia was more pronounced in eyes in which the epi‐off technique was used, and the recovery time was shorter for eyes treated using epi‐on CXL. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

The prevalence of macular cysts in patients with clinical cone-rod dystrophy determined by spectral-domain optical coherence tomography.

ABSTRACT Background: To determine the prevalance 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. Material and Methods: 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. Results: 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. Conclusions: Although macular cysts are a common feature of various hereditary night-blinding retinal dystrophies, these were not identified in our cohort of CORD patients.

High-resolution spectral domain optical coherence tomography images of alstrom syndrome.

Alström syndrome is a multisystemic disorder characterized by cone-rod dystrophy, hearing loss, obesity, insulin resistance and hyperinsulinemia, type 2 diabetes mellitus, dilated cardiomyopathy, and progressive hepatic and renal dysfunction. The cone-rod retinal dystrophy usually develops within a few weeks after birth. The authors examined a young boy with Alström syndrome by means of microperimetry and spectral domain optical coherence tomography (OCT). Instead of the typical alterations observed in cone-rod dystrophies, the characteristics of the central foveal tissue suggest signs of retinal immaturity, with only a single layer of short, thick cones and rods and immature short outer segments. High-speed and high-resolution spectral domain OCT allowed a detailed analysis of retinal layers in a young patient with Alström syndrome for the first time.

New retinal imaging for the visualization and analysis of vitreoretinal interface (VRI) by short-wavelength scanning laser ophthalmoscope (swSLO).

Background: The purpose of the study was to evaluate vitreoretinal interface (VRI) alteration with a short-wavelength scanning laser ophthalmoscope (swSLO), the Nidek F-10, and compare the results with those obtained by means of spectral-domain optical coherence tomography (SD-OCT). Methods: Thirty-six eyes were studied (20 patients, mean age 68 ± 12.3 years). All patients underwent a complete ophthalmologic examination, which comprised SD-OCT and Nidek F-10 analysis with short-wavelength blue laser. Eyes were divided into four groups depending on the degree of VRI alteration observed with the swSLO and SD-OCT. Statistical analysis was performed using the Chi-square test. P values less than 0.05 were considered statistically significant. Results: OCT analysis: eight eyes (22%) grade 0 (no abnormalities), 15 eyes (42%) grade 1 (preretinal cellophane); seven (19%) grade 2 (preretinal wrinkling); six (17%) grade 3 (macular pucker or hole). Nidek F-10 analysis: seven (19%) grade 0, 16 (45%) grade 1; seven (19%) grade 2; six (17%) grade 3. Chi-square = 0.099, P = 0.992. There was no statistically significant difference between the two instruments. Conclusion: Nidek F-10 allows both a quantitative and a qualitative evaluation of VRI and is equal to SD-OCT in detecting alteration of the inner portion of the retina, providing an easy way to evaluate and map differences in the inner vitreoretinal surface.

Use of MP-1 microperimetry in optic disc pit and secondary retinoschisis

The optic nerve head pit is a congenital anomaly of the optic disc due to imperfect closure of the superior edge of the embryonic fissure. We studied in detail by means of fluorescein angiography (FLA), microperimetry (fundus related perimetry), and ocular coherence tomography (OCT) the case of a 30-year-old woman who had an optic pit with secondary retinoschisis in her right eye.