According to etiology of low vision, patients fell into 4 groups: Group A: patients with low vision attributed to a macular lesion; group B: patients with low vision attributed to optic atrophy; group C: patients who had both macular and optic nerve disease and group D: patients with low vision due to other causes. The etiology of low vision among patients enrolled in this study is summarized in Table 2.

At the time of presentation all patients were no longer satisfied with their present spectacles or LVAs if they were using any. The refractive errors of patients are represented as spherical equivalent and summarized in Table 1.

In accordance with the WHO categories of visual loss, thirty-two patients (64%) were visually impaired-BCVA worse than 6/18, but better than 6/60-, 8 patients (16%) were severely visually impaired-BCVA worse than 6/60, but better than 3/60-, while 10 patients (20%) were legally blind (BCVA worse than 3/60).

Differences in near VA between Keeler system and point system were observed, so we chose to report the results in Point system as it was in Arabic language and as a continuous text, while Keeler A system was in the form of Landolt's broken rings and as isolated symbols which might cause false high results. We did not include the results of 3 children who were considered non-proficient readers. At time of presentation only 3 patients (6%) could discern N8 print, 8 patients (17%) could discern N10 print, 5 patients (11%) could discern N24 print, 8 patients (17%) could discern N32 print, and 23 patients (49%) could only discern N48 print or even larger fonts.

Improvement of distance VA using telescopes showed statistical significance (Wilcoxon signed rank test, p<0.001). Twenty-eight patients (56%) showed improvement of 5 lines or more. Nineteen patients (38%) showed improvement of 3-4 lines and 3 patients (6%) showed mild improvement of 1-2 lines. The improvement in the groups according to the etiology is described in Figure 1. Of the 28 patients who showed an improvement of 5 lines or more, 64% belonged to group A, 14% belonged to group B, 4% belonged to group C and 18 % belonged to group D.

After provision of low vision aids, there was a significant increase in the number of patients who could discern N8 print and better. Twenty seven patients (57%) could discern N8 print and better. Thirty-one patients (66%) at presentation could only discern N32 or larger print, this number markedly decreased to only 2 patients (4%) after use of LVAs. Results of improvement in near visual acuity are detailed in Table 3 and Figure 2. The overall improvement in near visual acuity was statistically significant (Wilcoxon signed rank test, p<0.001).

A correlation between improvement in near VA and the pre-correction level of distance VA was observed. Using LVAs, twenty-two patients (68.75%) of the visual impairment group could read print size N8 or better; 2 patients (25%) of the severe visual impairment group could discern N8, while three patients (33.3%) of the blind group could discern N8 print. Therefore the best improvement was achieved in the group of patients that were in the visually impaired group.

Twenty-seven patients (54%) asked for an aid to help them in near tasks, 17 patients (34%) asked for aids to help in both near and distance tasks, while only 6 patients (12%) needed aids to help in distance tasks only. Patients asking for distance tasks only were children.

The magnification level of prescribed aids ranged between 2X and 10.1X. More than half of the patients (58%) used aids with a range of power between 2X and 5X, while 42% of the patients used aids ranging from 5.4X to 10.1X. High powered reading aids (microscopes) were the most commonly used near aid (54%), followed by hand-held magnifiers (24%). Figure 3 illustrates the types of near aids used by our patients.

Non-optical aids were prescribed for 32 patients (64%). The most common were the direct illumination and reading stands. Large print text was used to assist 3 patients (6%) who only needed to read The Holy Books which were the only commercially available texts in large print in Egypt.

Figures 4 and 5 summarize the patients' responses to questions about the frequency of use of the aid and duration of time of use of the LVAs per day. According to patients response to a question about the ease of use of the aid, 18 patients (36%) reported the aid being easy to use, 23 patients (46%) reported it a little difficult, 8 patients (16%) said it was very hard to use, although those patients reported being able to manage the difficulty with time. One patient (2%) reported that it was extremely difficult to use the aids alone, and hence additional in-office training sessions were planned. The most commonly reported complaints were the clumsy appearance of the aids, high cost, short working distance and loss of focus. Figure 6 illustrates the incidence of complaints among the 50 patients. When patients were asked if they would rate their satisfaction with their aids as highly, moderately or poorly satisfied, fifteen patients (30%) reported to be highly satisfied, 23 patients (46%) were moderately satisfied while 12 patients (24%) were poorly satisfied. As for the overall rehabilitation service, 34 patients (68%) mentioned that the service was very helpful, 13 patients (26%) reported it was helpful, while the remaining 3 patients (6%) reported being frustrated about the service.

The findings of our study confirm that the provision of low vision aids is associated with a statistically significant improvement in both near and distance visual acuities and with patients' satisfaction.

Despite the fact that provision of low vision services prove to be associated with improved functional status and quality of life of patients with visual impairment,^{2, 10} many of the patients or their health care providers are either unaware of the availability of such services or have no access to it.^{11, 12, 13, 14} The problem is even worse in developing countries where low vision services are striving to exist,^{5, 16} and where the economical situation affects the ability of both the health institutions and individuals who are visually impaired to afford such services. In light of the expected increase of numbers in the patients with visual impairment,^{1, 17} and with the scarcity of studies evaluating the effectiveness of low vision aids,^{2, 4, 18} we aimed at quantifying the improvement in distance and near visual acuity after prescribing and training patients in the use of suitable low vision aids. We also aimed at identifying what kind of complaints could hinder the continuity of use of prescribed aids and how would the patients rate their satisfaction about the rehabilitation service.

Interestingly, unlike the epidemiological results of many studies,^{8, 19, 20} the mean age of our patients' sample was much less. We assume that the reason behind this is the fact that older patients in developing societies like Egypt live with other family members and depend on them much more. Such elderly patients become more reluctant to seek seemingly complicated aids that need special training and new adaptive techniques. Furthermore the illiteracy rate in developing societies is very high especially among older patients,²¹ while the need to read represents the major requirement for an age-matched group of patients from developed countries. The life expectancy is also less in developing countries.¹⁶ For these reasons we assume that those young, literate socially active patients in developing countries are mainly the ones who seek low vision services.

In accordance with this was the etiology of visual impairment among our sample. Sixty-eight per cent of the patients in this study had macular diseases, yet only 6% of those were due to age-related causes such as AMD, while the rest were mostly congenital in nature. This represents another point of difference compared to studies reported elsewhere.^{19, 20, 22}

We observed that the improvement in distance visual acuity was not dependent on the underlying pathology, since the etiology profile of the patients showing improvement in distance visual acuity to 5 lines or more was almost identical to the etiology profile of the whole patients' sample. Similar findings were previously reported.² On the other hand a correlation was observed between the improvement in near VA and pre-correction level of distance VA, where patients with a better level of pre-correction distance VA achieved a better post-correction near VA. Such an observation could be utilized as a success predictor when providing LVAs.

Analysis of the complaints of the patients after the use of aids in this study revealed that the clumsy appearance was the main complaint, especially when the patient started to use the aid in front of relatives, work or class mates. Another reason was the need to adopt new techniques for reading or using the LVAs with a sense of permanent loss of pre-visual impairment reading abilities, which was perceived as a declaration of patient's permanent handicap. Patients reporting to be frustrated about the service were mainly those who had unrealistic expectations even after counseling and discussion about the limitations of LVAs in terms of its functional as well as cosmetic aspects.

One limitation to the accurate assessment of the visual performance of patients in this study was the use of only the ability to read small print, without assessing neither the speed nor the duration of reading or performing the visual tasks. Another limitation was the inability of our institute to provide patients with trial closed-circuit televisions due to financial restrictions, as well as our assumption that our patients would not be able to afford such aids even if they prove effective.

This study is the first in Egypt to report the outcome of a low vision rehabilitation service. Relative to the costs of visual impairment, the provision of low vision rehabilitation services seem to be quite low. In a developing country such as Egypt, increased awareness of the public and the medical health providers of the availability and the benefits of such services is expected to help improve the quality of life of patients who are visually impaired. The concept that nothing further could be done for individuals who are visually impaired might be changed and perhaps health authorities might eventually be encouraged to finance such services.

The author(s) have no conflicts of interest or proprietary interest in any of the topics or products presented in this manuscript.

Funding: Research grant for Mansoura Ophthalmic Center from Mansoura University, Egypt.

We thank all of the participating patients and their families for their interest and generosity.