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Purpose: To evaluate refractive, binocular vision and ocular alignment outcomes of photorefractive keratectomy (PRK) for the treatment of hyperopia in esotropic patients., Methods: Medical charts of hyperopic patients with full or partial accommodative esotropia (FAE or PAE) or consecutive exotropia (CE) undergone PRK from 2011 to 2014 were reviewed. The primary outcome was to assess the efficacy of PRK in improving ocular alignment. The secondary outcomes were the assessments of uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent (SE) and stereoacuity., Results: Sixty-four eyes of 32 hyperopic patients were included. Three patients were affected by FAE, 24 by PAE and 5 by CE. All FAE patients and 4 PAE patients underwent only PRK; the remaining 25 patients underwent PRK plus strabismus surgery. After PRK, the mean corrected esodeviation decreased significantly in the overall esotropic population [7.15 ± 9.42 prism diopters (PD) vs. 5.04 ± 8.83 PD; p = 0.03] and in particular in the group with small-angle esodeviation (< 20 PD). Conversely, the only 2 patients with an angle of strabismus ≥ 20 PD as well as all CE patients did not show any postoperative variation of the deviation angle. Mean preoperative BCVA did not differ from postoperative UCVA (p = 0.19), while the mean postoperative SE decreased significantly after PRK (p < 0.0001)., Conclusions: Our study confirmed that PRK eliminates the accommodative component of the deviation. In addition, this procedure seems to reduce or eliminate also the non-accommodative component of esodeviation (especially in small-angle deviation), thus suggesting to postpone strabismus surgery after PRK when esotropia and hyperopia coexist.

Three epikeratoplasty buttons (one aphakic and two myopic) prepared by the freeze technique were removed two to nineteen months after surgery. A complete morphological and immunohistochemical study was performed on these buttons in order to gain insight into the reasons for epikeratophakia failure. Histopathological studies with light microscopy and scanning and transmission electron microscopy were performed. All three cases showed an anomalous process of re-epithelialization: in the first, the epithelium over the donor cap was almost completely absent, with many abnormalities; in the second, the epithelium was irregular, with a varying number of cell layers and poor adhesion between cells; in the third, the development of an epithelial cyst between the tissue lens and the cornea of the host caused the failure of the epikeratoplasty. The specimens were cultured 'in vitro' and the cells grown typed for HLA antigens. The antigen panel was the same as that of the host. Immunohistochemistry showed CD3- and CD8-positive cells in the stroma, proving the activity of T-suppressor lymphocytes in a cell-mediated immunoreaction.

An interferometric acuity device (Takata) has been used to study visual resolution in individuals with possible demyelinating disease. The instrument employed provides a large field with a continuous range of grid or fringe frequencies and a relatively intense (10(5) mean photopic trolands) stimulus. After a brief period of time with eyes closed, resolution thresholds of patient are repeatedly determined during a five minute period. In all individuals suspected of having a demyelinating disease tested to date, a fall off in resolution capability has been found in time when using this intense stimulus display. This occurs whether eye signs have been present, are present or have not yet been observed. Normal observers do not exhibit comparable decrements. The fall off in resolution capability may or may not occur at lower stimulus levels, and is often not revealed when testing routine Snellen acuity. Outer and inner retinal pathology (division based on vascular support) do not cause a comparable fall off in resolution in time. The interferometric acuity test is a non-invasive, easily applied test.

The most widely-used techniques for testing visual function in babies are reviewed. Advantages and limitations of optokinetic nystagmus testing, visual evoked responses and preferential looking techniques are considered. The theoretical basis and the clinical applicability of those techniques are outlined. Other simple methods are considered as well, which allow practicing ophthalmologists to assess the presence or absence of vision in babies. The importance of early diagnosis for prevention and treatment of visual deficits in babies is stressed.

The fusional nature of the phenomenon of prism compensation in strabismus was studied. At first a general survey was performed on the characteristics of anomalous fusional movements (a.f.m.). The influence of different kinds of stimuli (foveal and peripheral fusionable targets, non-fusionable targets) on a.f.m. was considered, and finally the effect of a sensorial obstacle to fusion was investiaged. It is concluded that 'eating up' the prisms is definitely a phenomenon of fusional nature, although it has special features which are interpreted as a consequence of the initial pathological condition. In this way the puzzling prism compensation also in subjects with normal retinal correspondence may be explained.

Visual acuity was examined in patients successfully treated for strabismic amblyopia, and with equal refractive error in the two eyes (no more of 4 diopters of hyperopia). Patients able to freely alternate fixation showed equal visual acuity in the two eyes without optical correction. An optical correction in front of the ex-amblyopic eye was needed, in order to achieve equal visual acuity in patients unable to freely alternate fixation. No correction was necessary for the sound eye. This difference is attributed to a residual anomaly of accomodation of the ex-amblyopic eye. It is concluded that the concept of cure of strabismic amblyopia based on the attainment of equal visual acuity needs re-evaluation.

Functional amblyopia has been considered as a homogeneous syndrome for the last decade or so, mainly on the basis of animal experiments. Recently, important differences have been shown to exist between strabismic and anisometropic as well as deprivation amblyopia. Even strabismic amblyopia may be subdivided in different classes. These statements are supported with experimental and clinical data. Clinical relevance of the heterogeneity of amblyopia is discussed particularly in the view of the concept of its cure.

An automatized computerized deviometer is presented based on an infrared TV camera, an image analyzer and a computer. With this instrument it is possible to follow step-by-step the various diagnostic procedures in strabismus and to answer the following questions: is there a strabismus? is it convergent, divergent or vertical strabismus? what is the angle of deviation? which is the paralytic or paretic muscle in the case of incomitant strabismus?

The treatment of the infant who is born with sensory deprivation amblyopia is one of the most difficult therapeutic problem sets facing the ophthalmologist today. This group of anomalies has many forms, the most common of which seems to be unilateral and bilateral cataracts. Substantial advances have been made, however, in many aspects of therapy for infants who have this set of problems. We have come to realize that it is essential to address these conditions at the first moment that is consistent with the safety of the child. New techniques in cataract extraction have reduced the time course of surgical treatment, reduced the frequency of secondary cataracts, and sustained the patency of the visual pathway. Unfortunately, practitioners who engage in the surgery may not have the back-up skills in advanced contact lens fitting, correction of aniseikonia, and, in some instances, the strabismological complications which are encountered. Further, improved means of assessment of visual acuity, binocular vision, and other visual characteristics of these infants are only in the developmental stages at this time. Thus, we propose to present the problem in an orderly manner. We shall first review the types of cases and problems. We will then discuss surgical techniques and the information which must be determined during examination under anesthesia (EUA) for the purposes of visual correction. We will then describe the designs of the spectacle lens and/or spectacle/contact lens combinations that are used to correct the resultant aniseikonia and anisometropia. We will address the approaches to patching and techniques on how to best achieve binocular vision in these patients. Separately, means and methods of assessment of vision by preferential looking, visual evoked response, optokinetic nystagmus, and tests of other visual functions will be explored. In summary, we will try to tie together the entire therapeutic regimen that can be used in the treatment of these patients.