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Rehabilitation with MP1 biofeedback training of a posterior microphthalmos case

2013; Elsevier BV; Volume: 48; Issue: 5 Linguagem: Inglês

10.1016/j.jcjo.2013.02.006

1715-3360

Lisa Toto, Luca Di Antonio, Alessandra Mastropasqua, Chiara De Nicola, Leonardo Mastropasqua,

Retinal Development and Disorders

Posterior microphthalmos is a rare disorder that affects the posterior ocular segment in cases with a normal anterior segment. They exhibit recessive form of inheritance and no associated systemic abnormalities.1Spitznas M. Gerke E. Bateman J.B. Hereditary posterior microphthalmos with papillomacular fold and high hyperopia.Arch Ophthalmol. 1983; 101: 413-417Crossref PubMed Scopus (69) Google Scholar, 2Khairallah M. Messaoud R. Zaouali S. et al.Posterior segment changes associated with posterior microphthalmos.Ophthalmology. 2002; 109: 569-574Abstract Full Text Full Text PDF PubMed Scopus (91) Google Scholar, 3Kiratli H. Tumer B. Kadayifcilar S. Bilateral papillomacular retinal folds and posterior microphthalmus: new features of a recently established disease.Ophthalmic Genet. 2000; 21: 181-184PubMed Google Scholar Its main characteristics are high hyperopia and bilateral papillomacular retinal folds. Posterior microphthalmos with bilateral papillomacular retinal folds has been found to be associated with amblyopia probably related to the site of macular fold at the fovea.2Khairallah M. Messaoud R. Zaouali S. et al.Posterior segment changes associated with posterior microphthalmos.Ophthalmology. 2002; 109: 569-574Abstract Full Text Full Text PDF PubMed Scopus (91) Google Scholar Nystagmus also has been a clinical finding of this rare congenital disease.3Kiratli H. Tumer B. Kadayifcilar S. Bilateral papillomacular retinal folds and posterior microphthalmus: new features of a recently established disease.Ophthalmic Genet. 2000; 21: 181-184PubMed Google Scholar We report a case of a 7-year-old female with posterior microphthalmos with bilateral papillomacular folds, presenting with nystagmus and bilateral amblyopia. Best corrected visual acuity was 0.4 logMAR, and cycloplegic spherical equivalent refraction was +14.00 D in both eyes. She had horizontal saccadic nystagmus. The anterior segment and ocular alignment at distance and near were normal. Optical coherence tomography (OCT) measurements showed an anterior chamber depth of 2.61 mm in the right eye (RE) and 2.68 mm in the left eye (LE), and a cornea white-to-white diameter of 11.01 mm in the RE and 10.61 mm in the LE. The axial length measured using A-scan echography was of 17.15 mm in the RE and 17.21 mm in the LE. Fundus examination after pupil dilation showed bilateral papillomacular retinal folds extending from the fovea nasally (Fig. 1). Spectralis OCT (Heidelberg Retina Angiograph (HRA) + OCT; Heidelberg Engineering, Heidelberg, Germany) scans showed neurosensory folding involving the inner layers, the outer plexiform layer, and part of the inner nuclear layer. The external limiting membrane and photoreceptor inner segment–outer segment junction showed a normal profile. The retinal pigment epithelium choriocapillaris complex and the underlying choroid showed normal profile and morphology (Fig. 2).Fig. 2Spectral-domain optical coherence tomography (vertical scan) scans showing the presence of neurosensory folding involving the inner layers, the outer plexiform layer, and part of the inner nuclear layer. The external limiting membrane, photoreceptor inner segment–outer segment junction, and the retinal pigment epithelium–choriocapillaris complex showed normal profile and morphology.View Large Image Figure ViewerDownload (PPT) Microperimetry examinations using the MP1 instrument (Nidek Technologies Srl, Padova, Italy) were performed under dark conditions after pupil dilation: a red circle of 1 degree was used as fixation target, white background luminance of 4 apostilbs, stimulus size Goldmann III with projection time of 200 milliseconds, and a customized grid of 40 stimuli covering the central 10-degree diameter circle of the central retina. A 4-2-1 staircase strategy was used. At baseline, mean retinal sensitivity was 19.2 dB in the RE and 19.9 dB in the LE. Fixation behaviour was relatively unstable with 55% of the fixation points within the 2-degree diameter circle and 94% of the fixation points within the 4-degree diameter of the central retina in the RE, and 74% of the fixation points within the 2-degree diameter circle and 98% of the fixation points within the 4-degree diameter in the LE. The low-vision rehabilitation program administered consisted of 10 training sessions of 10 minutes for each eye, performed once a week using the MP-1 biofeedback training module. The fixation target used was a flickering black and white checkerboard pattern. Following the training sessions, best corrected visual acuity was 0.18 logMAR in both eyes. Mean retinal sensitivity was 20 dB in both eyes. Fixation behaviour was relatively unstable in the RE, with 67% of the fixation points within the 2-degree diameter circle and 94% of the fixation points within the 4-degree diameter of the central retina, and was stable in the LE, with 89% of the fixation points within the 2-degree diameter circle and 98% of the fixation points within the 4-degree diameter (Fig. 3, Fig. 4, Fig. 5).Fig. 4A, Image shows fundus-related perimetry of left eye at baseline presenting relatively unstable fixation behaviour in the foveal area, with 74% of the fixation points within the 2-degree diameter circle and 98% of the fixation points within the 4-degree diameter. B, Image shows improvement of fixation after visual rehabilitation with stable fixation, with 89% of the fixation points within the 2-degree diameter circle and 98% of the fixation points within the 4-degree diameter.View Large Image Figure ViewerDownload (PPT)Fig. 5A and B, Images show fixation stability at baseline of right and left eye, respectively. C and D, Images show evidence of an increase of fixation stability with concentration of fixation points in a smaller area.View Large Image Figure ViewerDownload (PPT) At baseline in the RE, total shift of fixation on x-axis (Xmax – Xmin) was 6.92 degrees (2.31 – [–4.61]) and total shift of fixation on y-axis (Ymax – Ymin) was 3.73 degrees (1.99 – [–1.74]) with a mean velocity of 2.51 deg/s; after rehabilitation, total shift of fixation on x-axis (Xmax – Xmin) was 5.42 degrees (3.68 – [–1.74]) and total shift of fixation on y-axis (Ymax – Ymin) was 3.12 degrees (1.56 – [–1.56]) with a mean velocity of 2.43 deg/s. In the LE, total shift of fixation on x-axis (Xmax – X min) was 8.23 degrees (4.55 – [–3.68]) and total shift of fixation on y-axis (Ymax – Ymin) was 8.17 degrees (5.86 – [–2.31]) with a mean velocity of 3.69 deg/s; after rehabilitation, total shift of fixation on x-axis (Xmax – Xmin) was 4.05 degrees (2.80 – [–1.25]) and total shift of fixation on y-axis (Ymax – Ymin) was 3.37 degrees (1.25 – [–1.12]) with a mean velocity of 2.30 deg/s. Microperimetric rehabilitation with audio feedback has been described in patients with macular diseases and loss of foveal function. It was used to train patients to use preferred retinal loci (PRL) or to create another PRL in the proximity of the fovea.4Vingolo E.M. Cavarretta S. Domanico D. Parisi F. Malagola R. Microperimetric biofeedback in AMD patients.Appl Psychophysiol Biofeedback. 2007; 32: 185-189Crossref PubMed Scopus (52) Google Scholar, 5Mezawa M. Ishikawa S. Ukai K. Changes in waveform of congenital nystagmus associated with biofeedback treatment.Br J Ophthalmol. 1990; 74: 472-476Crossref PubMed Scopus (34) Google Scholar, 6Sharma P. Tandon R. Kumar S. Anand S. Reduction of congenital nystagmus amplitude with auditory biofeedback.J AAPOS. 2000; 4: 287-290Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar In our patient, microperimetric rehabilitation training with pattern stimulation improved fixation behaviour, retinal sensitivity, and visual acuity. In the presence of a central scotoma, it has been postulated that biofeedback training can help the brain to use an input from a new PRL to access the foveal occipital cortex. Auditory feedback stimulate the attention of the patient with increasing the time spent on the PRL. Furthermore, a pattern fixation target enhances inner retina integration processes and optimizes stimulus processing, recognition, and in-brain transmission.7Buia C. Tiesinga P. Attentional modulation of firing rate and synchrony in a model cortical network.J Comput Neurosci. 2006; 20: 247-264Crossref PubMed Scopus (87) Google Scholar In our case, stimulation of fixation with a pattern stimulus coupled to auditory biofeedback probably increasing foveation time improved stability of fixation. Moreover, increased foveation time probably reduced nystagmus and, consequently, improves visual function.