ORIGINAL ARTICLE

Refractive Errors and Low Vision

Rehabilitation in Patients with

Oculocutaneous Albinism

Deniz Altınbay¹

¹Private NIV Eye Center, Adana, Turkey

ABSTRACT

Purpose: To evaluate the types of refractive errors in patients of Oculocutaneous Albinism and find their

compliance (OCA) to low vision aids.

Study Design: Descriptive observational study.

Place and Duration of Study: Provincial Directorate of Health, Adana City Education and Research Hospital,

from 2010 to 2018.

Material and Methods: Seven hundred and fifteen patients attended the hospital between 2010 and 2018 with

the complaint of low vision and 31 patients with OCA were included in this study by convenient sampling. Best

corrected distance and near visual acuity (VA) was measured along with the complete ocular examination.

Patients were classified according to low vision and refraction degrees. High degree near eyeglasses, Galilean

and Keplerian telescopes, magnifiers and special filter glasses were used as low vision aids (LVA).

Results: Mean age was 16.45 ± 12.72 years. On admission, mean distance VA was 0.12 ± 0.07 [mean log MAR

0.9], near VA was 1.48M ± 0.74M, astigmatism was 4.02 ± 1.45 diopters (D), and spherical equivalents were 1.54

± 4.96 D. Hypermetropia was seen more frequently than myopia. Twenty-seven (87%) patients were prescribed

telescopes for distance. Near visual acuity increased from 1.4M ± 0.7M to 0.9M ± 0.4M after rehabilitation. There

was an increase in distance visual acuity in all patients (p < 0.001). Seventeen (63%) patients bought the

telescope, and 15 (55%) patients used the device. The most preferred special filter glasses were 450nm (39%)

and 540 nm (25%).

Conclusion: Astigmatism in oculocutaneous albinism was with the rule and the most commonly detected

refractive error was hypermetropia. Patients are non-compliant in buying telescopes in which case tablet and

computers with special applications for low vision can be better options.

Key Words: Albinism, Low vision, Low vision rehabilitation, Refraction, Refractive errors.

How to Cite this Article: Altinbay D. Refractive Errors and Low Vision Rehabilitation in Patients with

Oculocutaneous Albinism, Pak J Ophthalmol. 2020, 36 (2): 151-156.

Doi: 10.36351/pjo.v36i2.978

melanin pigment that gives color to skin, hair, and

eyes. Approximately, one out of 17000 people is

INTRODUCTION

Albinism is a congenital, genetic, heterogeneous

affected by albinism. It is the condition of absence or

disease characterized by the defect in the synthesis of

lack of melanin pigment. Ocular Albinism (OA) is the

type of albinism which only affects the eye;

oculocutaneous albinism (OCA) is the type of albinism

that affects eye, hair, and skin. The clinical picture

varies depending on the presence or absence of

Correspondence to: Deniz Altınbay

Private NIV Eye Center, Adana/Turkey

Email: denizaltinbay01@gmail.com

151

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 151-156

Refractive Errors and Low Vision Rehabilitation in Patients with Oculocutaneous Albinism

tyrosinase.

Nystagmus,

photophobia,

iris

program. In this program, patients were given training

on using telescopic glasses, adjusting distance in close

reading, using a magnifying glass, using a digital

magnifying glass and reading exercises at different

points according to the point size they saw in the slow

reading speed. The statistical analysis of the data was

analyzed with IBM SPSS Statistics Version 20.0

package program. Categorical variables were

expressed as number and percentage, and numerical

variables were presented as mean and standard

deviation. The chi-square test was used to compare

categorical variables between groups. Fisher’s Exact

test result was given where the number was

insufficient. Shapiro Wilk test was used to determine

whether the numerical variables have a normal

distribution or not. The Mann Whitney U test was used

to compare the abnormally distributed numerical

variables between the two groups. The Wilcoxon

Signed Rank test was used to compare LVA values

before and after the procedure. The level of statistical

significance was set at p < 0.05.

transillumination, foveal hypoplasia, high degree

refractive errors and decreased visual acuity are seen

as clinical presentations^1-3.

This group of patients responds well to assistive

devices and filters for low vision. There is a significant

improvement in functional visual acuity in albinism

patients with low vision rehabilitation methods such as

proper light conditions and use of telescopic optical

devices^3-5. It was aimed in this study to evaluate low

vision rehabilitation methods and their outcomes in

patients with Oculocutaneous Albinism (OCA).

MATERIAL AND METHODS

Records of 715 patients who were admitted with low

vision between 2010 and 2018 in our department were

retrieved and 31 patients with oculocutaneous albinism

were included in the study. All procedures performed

in this study were in accordance with the ethical

standards of the institutional and national research

committee [Provincial Directorate of Health Adana

City Education and Research Hospital – 13 February

2019/number of decision: 372) and with the 1964

Helsinki declaration and its later amendments or

comparable ethical standards.

RESULTS

Thirty-one (4.3%) patients had oculocutaneous

albinism. Sixteen (51%) were male, and 15 (48%)

were female, with mean age of 16.45 ± 12.72. Their

ages ranged from 5 to 58 years. When two patients

with 47 and 58 years of age were removed, all patients

were under 40 years of age. 25 (80%) patients were

under the age of 23, indicating that they were in the

education period. Distance visual acuity of three

patients who did not attend school was evaluated with

Snellen E-test chart and near visual acuities were

measured in points in Times New Roman with

different characters, and in terms of “M” equivalent in

MNREAD reading acuity chart.

Visual

acuity,

refraction,

Biomicroscopic

examination, intra ocular pressures and fundoscopic

examination were performed. Cycloplegic retinoscopy

was performed. Distance visual acuities (VA) were

measured with distance acuity chart for low vision

individuals (Test Charts for Low Vision Patients,

ZEISS, Germany) and then refractive errors were

corrected. The visual impairment of patients was

divided into three groups, according to the WHO-ICD-

10 classification; moderate vision impairment (< 0.3

and ≥ 0.1), severe visual impairment (< 0.1 and

≥ 0.05) and blindness (< 0.05 and ≥ 0.02)⁶. Degrees of

Myopia and hyperopia were also grouped as low,

medium and high. Near visual acuity was measured by

MNREAD acuity chart (Idil SA et al)⁷. Patients read

the reading chart from a distance at which they could

see most clearly. Near vision correction for age was

performed in patients over 40 years. Consequently, the

magnification power and the reading distance required

were calculated.

The mean distance visual acuity was 0.12±0.07

(0.02 – 0.32) [mean log MAR 0.9], and the mean near

visual acuity was 1.4M ± 0.7M (4M – 0.6M). The

mean astigmatism was 4.1 ± 1.5 diopter (1.50 – 6.25),

and all astigmatism patients were in accordance with

the rule. Astigmatism in all patients was higher than

1.50 D. When the spherical equivalents were

calculated, it was 1.54 ± 4.96 diopters (between -0.75

and +11.00). Twenty-one (67.7%) patients had

hypermetropia, and 10 (32.2%) had myopia.

Hypermetropia was seen more frequently than myopia.

Twenty (64%) patients had hypermetropia greater than

1.50 diopter. Only one patient's hypermetropia was

lower than 1.50 diopter. Myopia was present in 10

Low vision aids (LVA), such as high degree near

eyeglasses, Galilean and Keplerian telescopes, sphere

magnifiers and special filter glasses were used. All

patients were included in the visual rehabilitation

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 151-156

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Deniz Altınbay

(32.2%) patients. 3 (9%) had low (-4.00 and less), 4

(12%) had moderate (-4.00 and -6.00) and 3 (9%) had

high (-6.00 and above) myopia.

preferred 500 nm, three patients preferred 550 nm and

one patient preferred 600 nm. Three patients did not

want a special filter glass.

Keplerian Telescope (58%) and Galilean

Telescope (36%) were recommended to 18 patients.

LVA improved the visual acuity at least two log MAR

line (from a decimal to a logarithmic system) in all

patients. The distance visual acuity improved from

0.12 ± 0.07 to 0.56 ± 0.37 with low vision

rehabilitation. There was an increase in distance visual

acuity in all patients (p < 0.001) (Figure 1).

In the group with poor VA before the low vision

rehabilitation, it was found that the number of the

telescopes purchased or purchased but then not used

was few. However, it was statistically insignificant

(p = 0.213). Eleven (61%) patients with severe visual

impairment-blindness group and 5 (39%) patients in

the moderate visual impairment group did not use

telescopes (Table 1) There was no significant

relationship between the degree of refractive error and

the use of telescopic glasses (p = 0.349) (Table 1).

Table 1: Some features of patients according to the use of

telescopic glasses.

Age

0-22

23-40

40+

12 (%50) 12 (%50)

2 (%40)

1 (%50)

3 (%60) 0.919

1 (%50)

Fig. 1: Increase in visual acuity after the low vision rehabilitation.

Gender

Male

Female

8 (%50)

7 (%47)

8 (%50) 0.853

8 (%53)

Near visual acuity increased from 1.4M ± 0.7M to

0.9M ± 0.4M after rehabilitation. The ratio of patients

who could read a newspaper after near rehabilitation

increased from 42% to 98%.

Visual acuity

Moderate visual impairment

Severe visual impairment &

blindness

8 (%61)

5 (%39) 0.213

7 (%39) 11 (%61)

Telescope was prescribed to 27 (87%) patients.

Seventeen (54%) patients were prescribed Keplerian

telescope, and 10 (32%) were prescribed a Galilean

telescope. Only 62% patients purchased telescopic

glasses. 88% of the patients who purchased the

telescopic glasses used them. In total, 55% of patients

used telescopic glasses.

Telescopic system

Galileo system

Kepler system

6 (%55)

9 (%50)

5 (%45)

9 (%50)

Degree of refractive error

Low myopia/ hypermetropia

Medium myopia/ hypermetropia 3 (%75)

High myopia/ hypermetropia

1 (%25)

3 (%75)

1 (%25) 0.349

11 (%48) 12 (%52)

For near vision correction, 39% had VA (1.0 M

and less) which enabled them to read newspaper DISCUSSION

points, 77% had near VA (1.6 M and less) which

enabled them to read journal points without the

assistance of a device.

Patients with albinism usually present with

photophobia, high refractive errors and decreased

visual acuity^1,2,8. Therefore, this group of patients has

more difficulty in their school life than their peers, and

they use low vision units at an early age in order to

find solutions to these problems⁹. In our study, 80% of

patients with oculocutaneous albinism who presented

The most preferred special filter glasses were

450 nm (39%) and 540 nm (25%). Eleven patients

preferred 450 nm, seven patients preferred 540 nm,

three patients preferred 480 nm, three patients

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Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 151-156

Refractive Errors and Low Vision Rehabilitation in Patients with Oculocutaneous Albinism

to low vision unit were in their study years of life. In a

D of astigmatism. An increase of 2 lines or more was

seen in 48% of patients with astigmatism of 1.50 D or

more on any axis. In the current study, hypermetropia

was present in 67.7% of the patients and 95% of

hypermetropia patients were above 1.50 D. All

astigmatism patients were above 1.50 D. There was no

study of 120 oculocutaneous albinism patients using

low vision devices, the distance VA was found

between 0.98 log MAR and 0.77 log MAR¹⁰. In

another study of 50 eyes of 25 patients with

oculocutaneous albinism, distance visual acuity was

found to be 1.24 ± 0.50 log MAR⁹. Eballe AO et al

reported moderate visual impairment (0.48 < VA

≤ 1.00 log MAR) in 70% of patients¹¹. Twenty five

patients of albinism were reported in another study

with 7 ocular albinism and 18 oculocutaneous

albinism, the mean visual acuity was 0.9 log MAR¹².

Yaman et al measured visual acuity with Teller acuity

cards and Snellen and found visual acuity of 0.1 or less

in 62.5% of eyes¹³. The visual acuity was log MAR

0.5 and above in all patients in our study.

statistically

significant

relationship

between

improvement in visual acuity and degree of refractive

error. It could be because of limited number of cases in

our series.

In the study by Khanal et al, myopic astigmatism

was most frequent (34%) and spherical equivalent was

found to be between -1.59 ± 5.39D⁹.

The patients with albinism have been reported to

have weakness in accommodation¹⁵. However, in

albinism patients, it is reported that distant vision is a

bigger problem than near vision, half of the patients

can read the newspaper font without additional

magnifications, as the age increases, so do the need for

near glasses increases¹⁶.

Albinism is a heterogeneous group of diseases.

Some studies included all albinism patients, some

included only ocular albinism, and others included

complete ocular albinism. The ages also vary.

Therefore, there is no complete correlation among the

studies. However, the reduction in visual acuity is

emphasized in all articles. Patients in this particular

study with vision of log MAR 0.5 or less could be due

to the fact that the patients in our study were selected

among patients who were admitted to the low vision

unit.

In our study, we did not consider patients’

accommodation capacity but the reason of better near

visual acuity of our patients was the fact that 93% of

the patients were under 40 years of age, and even if it

was slightly weakened, it was due to their age.

In this study, approximately half of the patients

who were prescribed did not use the prescribed

devices. There was no statistically significant

relationship between refractive error and low vision,

and purchasing and using telescopic glasses. Patients

did not want to use them due to economic and

cosmetic reasons. In 2002, a study reported that only

50% of the visually impaired students used assistive

devices and only 51% of teachers were assisting their

students in using assistive technology¹⁷.

When refractive errors were analyzed, it was

observed that there were studies showing that

hypermetropia was more frequent; other studies

showed that myopia was more frequent while few

others reported equal prevalence of both refractive

errors. Hypermetropia was more frequent in studies by

Wildsoet et al. and Loshin et al^12,14. In these two

studies, with the rule astigmatism was seen in all

patients. In the cases of Loshin et al, the astigmatic

value ranged from 0.75D to 5.5D, and 44.8% had

astigmatism of 1D or more¹⁴. In our study,

hypermetropia was detected in 67.7% of the cases, and

myopia was detected in 32.2% of the cases. With the

rule astigmatism was seen in all our patients. Value of

astigmatism ranged between 1.50 and 6.25, and all

were above 1.5 D.

In recent years, tablets (iPad, Apple Inc,

Cupertino, CA), which have special programs for low

vision, have started to replace telescopic glasses in aid

and rehabilitation for low vision individuals. In a

randomized controlled study, young patients with low

vision using classic low vision assistive devices and

using iPad were compared, it was found that 90% of

patients using iPad reported using their tablets at least

once a day and found it easier¹⁸.

In another study with 120 oculocutaneous albinism

patients, an improvement in visual acuity was detected

in mild and moderate myopia, but this improvement

was mild with hyperopia above +1.50 D. With-the-rule

astigmatism was found in 37.5% of cases, 3.8% of the

cases were against-the-rule astigmatism. Forty seven

percent of patients with astigmatism had less than 1.50

In patients with albinism, filters make things easier

in their daily life⁹. As it is known, blue color in

daylight causes a lot of scattering due to a short

wavelength and causes glare and contrast loss¹⁹.

Special filter glasses filter short wavelengths, increase

Pakistan Journal of Ophthalmology, 2020, Vol. 36 (2): 151-156

154

Deniz Altınbay

contrast and reduce glare^20,21. In an analysis of low

vision individuals consisting of 15 adults and 80

children, all reported subjective improvement in

photophobia, eye fatigue, and eye discomfort when

using special filter glass. In this study, it was

concluded that color filters might contribute to the

rehabilitation of patients with low vision²².

3. Sowka J, Gurwood A. Low vision rehabilitation of the

albino patient. Optometry, 1991; 62: 533-6.

4. Tunay ZÖ, Çalışkan D, İdil A, Öztuna D. Clinical

characteristics and low vision rehabilitation methods for

partially sighted school-age children. Turk

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5. Hoeft W. Albinism--a clinician's low vision

perspective. Optometry, 1991; 62: 69-72.

6. World Health Organization (WHO), ICD-10 Version:

2016. Available at:

Sensitivity to light and low vision affect the

educational processes of individuals with albinism in a

negative way. Especially the difficulty in seeing the

board and the difficulty in reading textbooks are

important problems⁹. Low vision rehabilitation

techniques such as light modification and telescopic

optical devices have been reported to have significant

improvement in functional visual acuity in albinism

patients^1,3.

https://icd.who.int/browse10/2016/en#!/H55-H59

Accessed April 28, 2019.

7. İdil ŞA, Çalışkan D, İdil NB. Development and

validation of the Turkish version of the MNREAD

visual acuity charts. Turk J Med Sci. 2011; 41: 565-70.

8. Silver J. Low vision aids in the management of visual

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Kalua K, Kayange P, Spitzer MS, et al. Refractive

errors, visual impairment, and the use of low-vision

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Dohvoma AV. Refractive errors in patients diagnosed

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The limitation of our study was that it was a

retrospective data from patients less than 40 years. We

did not measure the accommodation in the patients of

albinism.

CONCLUSION

Astigmatism in oculocutaneous albinism was with the

rule and the most commonly detected refractive error

was hypermetropia. Patients are non-compliant in

buying telescopes in which case tablet and computers

with special applications for low vision can be better

options in this young population.

13. Yaman A, Berk AT. Clinical Features of patients with

albinism and their correlation with visual

acuity.Turkiye Klinikleri J Ophthalmol. 2008; 17: 161-

14. Loshin DS, Browning RA. Contrast sensitivity in

albinotic patients. Am J Optom Physiol Opt. 1983; 60:

158-66.

Ethical Approval

The study was approved by the Institutional

review board/Ethical review board.

15. Karlen E, Milestad L, Pansell T. Accommodation and

near visual function in children with albinism. Acta

Ophthalmol. 2019.

Conflict of Interest

Authors declared no conflict of interest

16. Collins B, Silver J. Recent experiences in the

management of visual impairment in albinism.

Ophthalmic Genet. 1990; 11: 225-8.

17. Abner G, Lahm E. Implementation of Assistive

Technology with Students Who Are Visually Impaired:

Teachers' Readiness. J Vis Impair Blind. 2002; 96: 98–

105.

Author’s Designation and Contribution

Dr. Deniz Altınbay; Consultant: Research design,

Data collection, Manuscript writing, Final review

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