Visual processing of color and shape in people with leprosy

Abstract The aim of this study was to analyze the contrast sensitivity of spatial luminance and the color discrimination thresholds of the protan, deutan, and tritan axes of people with leprosy. This study included 8 subjects with leprosy (M = 4, W = 4, M = 33.38 ± 8.7) and 8 healthy subjects (M = 4, W = 4, M = 30.89 ± 5.8). The contrast sensitivity was evaluated by the Metropsis software version 11.0 with vertical sinusoidal grids of frequencies of 0.2, 0.5, 1, 5, 10, and 16 cycles per degree of visual angle (cpd) and color vision by the desaturated Lanthony D15 tests and the trivector and ellipse protocols of the Cambridge Color Test. The results showed significant differences between the groups in the processing of spatial frequencies of 0.2 (U = 14; p = .018); 5.0 (U = 45.0; p = .001); 10.0 (U = 45.0; p = .001), and 16.0 (U = 45.0; p = .001) cpd. The difference in color recognition through D15d (U = 4.0; p = .002). Ellipse 2 (U = 10.0; p = .012) and ellipse 3 (U = 9.0; p = .009) were discriminated against. Overall, the results indicate that leprosy changes the visual processing of low, medium, and high spatial frequencies, as well as the sensitivity of the short wavelength (tritan line of confusion) and long (protan line of confusion) cones.

The prevalence of ocular complications in leprosy patients seen in the United Kingdom over a period of 21 years.

OBJECTIVE: The objective of this study was to determine the prevalence of ocular complications and blindness among leprosy patients presenting in the United Kingdom. METHODS: Observational prospective study. RESULTS: A total of 126 consecutive leprosy patients attending their ophthalmic visit were examined, out of which 18 patients were blind in one eye (14.3%) and five patients were blind in both the eyes (4.0%). Visual acuity of ≥ 6/18 was present in 96 patients (76.2%). A total of 65 patients (51.6%) had an ocular complication and 28 patients (22.2%) had a sight-threatening leprosy complication (lagophthalmos, severe corneal, or iris disease). The most common ocular complications were impaired lid closure (24 patients, 19%), impaired corneal sensation (20 patients, 15.9%), cataract (20 patients, 15.9%), mild corneal opacity (17 patients, 13.5%), and iris atrophy (17 patients, 13.5%). Impaired corneal sensation was associated with vision <6/18 (P<0.001, OR 13.5, 95% CI 5.14-35.44) and vision <3/60 (P=0.01 OR 6.42, 95% CI 2.15-19.15). Impaired lid closure was significantly associated with increasing age (P=0.029, OR 1.039, 95% CI 1.0-1.08) and vision <3/60 (P=0.03, OR 6.06, 95% CI 1.81-20.24). CONCLUSION: There is a significant rate of ocular complications and blindness seen in leprosy patients in the United Kingdom, and over one in five had a potentially sight-threatening ocular complication. Health professionals and all leprosy patients, including those cured of the disease, need to be aware that new eye symptoms and signs require prompt ophthalmology review to prevent avoidable blindness, due to the life-long risk of sight-threatening ocular complications.

Visual impairment in patients with leprosy in Adilabad District in the state of Andhra Pradesh, India.

The aim was to estimate the prevalence of eye problems in patients with leprosy and to assess the utilization rate of eye care services using cross-sectional case series design. All leprosy patients registered between April 2007 and June 2009 were included in the study. They were prospectively assessed by an internist for general health issues. An ophthalmic examination including assessment of visual acuity was conducted by an ophthalmologist. A total of 150 leprosy patients were examined, of which 78 (52%) suffered from pausi bacillary (PB) leprosy and majority were males (52%); 43 (29%) patients were literate. Nineteen (14%) patients had organ deformities and ocular lesions were seen in 12 (8%) patients, but 76 (51%) (95% CI 40.8-62.7) patients had earlier reported eye problems requiring intervention as assessed by the ophthalmic officer. Only 26 (17%) (95% CI 11.6-24.4) patients had sought eye care services earlier. Visual impairment was observed in 19 (12.6%) cases and blindness related to leprosy was seen in 5 (3.3%) patients. To conclude prevention of blindness among leprosy patients is possible only with strong coordination between the general health and eye care unit in the area with mandatory eye screening being made part of the treatment schedule for leprosy patients.

Evolution of vision reducing cataract in skin smear positive lepromatous patients: does it have an inflammatory basis?

AIM: To describe the incidence and risk factors of vision reducing cataract in skin smear positive lepromatous patients. METHODS: Prospective longitudinal cohort study: 212 newly diagnosed lepromatous patients were followed during the two years of treatment with multidrug therapy and for a further five years, with biannual ocular examinations. Incidence of vision reducing (< or =6/18) cataract was calculated as the number of patients with cataract per person year of cataract-free follow up among those who did not have cataract at baseline. RESULTS: Cataract was present in 27 (11%) of lepromatous patients at diagnosis. Forty nine patients (2.87%/person year (95% confidence interval (CI), 2.17% to 3.80%)) developed cataract during a total follow up period of 1704 person years; 45 of these were > or =41 years old and were followed for a total of 638 person years with an incident rate of 0.070 (95% CI, 0.0523 to 0.094). Stepwise multiple regression confirmed the association of age (per decade) (hazard ratio (HR) = 2.50 (95% CI, 1.82 to 2.78), p<0.001), clofazimine crystals on the cornea (HR = 49.92 (5.48 to 454.82), p = 0.001), grade 2 deformity in all limbs (HR = 3.17 (1.12 to 8.97), p = 0.029), and uveal inflammation (HR = 3.52 (1.42 to 8.67), p = 0.006). No significant association was found with oral steroids. CONCLUSIONS: Cataract develops at the rate of 7%/person year in lepromatous patients over 40 years of age. It is associated with increasing age, subclinical intraocular inflammation, and grade 2 deformity.

Impaired contrast sensitivity among leprosy patients with normal visual acuity.

Contrast sensitivity is a person's ability to identify an object from its background. Patients with normal visual acuity can have reduced contrast sensitivity and may experience trouble in identifying objects at night or moving around in dimly lit places. Contrast sensitivity has never been studied in leprosy patients having normal visual acuity. This study aimed to determine if contrast sensitivity is impaired in leprosy patients who have normal visual acuity and to identify possible associations with demographic, leprosy and ocular characteristics. A hospital based study measuring and comparing contrast sensitivity using the VCT 6500 chart in 127 consecutive leprosy patients without clinically apparent ocular complications and 123 non-leprosy controls was done. Contrast sensitivity was impaired in leprosy patients in all five spatial frequencies (1.5, 3.0, 6.0, 12 and 18 cycles/degree) investigated. Among leprosy patients, contrast sensitivity falling outside the normative range was associated with increasing age (adjusted OR 1.28, 95% CI: 1.14-1.42), being female (adjusted OR 11.05, 95% CI: 2.93-41.69) and having a grade 2 deformity (adjusted OR 6.43, 95% CI:1.68-24.61). Contrast sensitivity is impaired in leprosy patients having normal visual acuity. Elderly, deformed, female patients are particularly burdened with this vision loss.

Ocular complications in newly diagnosed borderline lepromatous and lepromatous leprosy patients: baseline profile of the Indian cohort.

AIM: To describe ocular manifestations in newly diagnosed borderline lepromatous (BL) and lepromatous leprosy (LL) patients in India. METHODS: Ocular complications, at enrolment, occurring in all new borderline lepromatous and lepromatous leprosy patients detected by active case finding within the geographically defined leprosy endemic area of the Gudiyattam Taluk in India from 1991 to 1997 who consented to ocular examinations every 6 months, during and 5 years after treatment with multidrug therapy (MDT), were studied. RESULTS: Orbicularis oculi weakness (4.62%), lagophthalmos (4.20%), ectropion (0.42%), trichiasis (0.84%), blocked nasolacrimal ducts (1.68%), pterygium (11.34%), impaired corneal sensation (53%), corneal opacity (10.5%), corneal nerve beading (1.68%), punctate keratitis (1.26%), keratic precipitates (4.62%), iris atrophy (1.68%), and cataract (12.6%) were ocular complications seen in the 301 lepromatous patients at enrolment. 4.6% had blind eyes. Increasing age was associated with ocular complications. 80% of patients were skin smear acid fast bacilli (AFB) positive. The LL/BL ratio was 1:6.4. 71% had some limb deformity. 44% had only leprosy related ocular complications (LROC), 28% had only general ocular complications (GOC) while 14% had both LROC and GOC. Ocular complications were significantly related to leg deformities. Corneal nerve beading was seen most in LL patients (100%) having high bacterial content. Lagophthalmos and muscle weakness were associated with reversal reactions. CONCLUSIONS: Corneal nerve beading occurs in LL patients with high bacillary count. Patients with reversal reaction are more likely to present with orbicularis oculi weakness and lagophthalmos. Leprosy related ocular complications and general ocular complications are significant problems in newly diagnosed lepromatous patients. Elderly, deformed, skin smear positive, lepromatous patients are associated with increased ocular morbidity and form a group that require acceptable and accessible eye care.

Clinical ocular study in leprosy patients at a sanitary dermatological hospital in Brazil.

This study is based upon the observation f 363 leprosy patients having different types of the disease. At the time of the examination, we did not have any previous knowledge about the type of leprosy the patients were having. Thus, the eye examination was done without the knowledge of clinical diagnosis. The ocular examination protocol covered the following: visual activity, facial muscle function, eyebrows, eyelashes, lacrimal system, pupil, eye motility, corneal sensitivity, Schirmir's test and study of the anterior segment of the ocular bulb with a slit-lamp. The study patients included 275 cases of lepromatous leprosy, 57 tuberculoid, 29 indeterminate and two dimorphous cases. The age of the patients ranged between 18 and 82 years, and 229 of them were males. Among those patients, 183 were whites, 23 were black and 157 were mulatto.

Study of ocular changes in leprosy patients.

In this study, 997 leprosy patients were examined, 528 of them with lepromatous leprosy (53%), 199 with borderline leprosy (20%), 167 with tuberculoid leprosy (16%) and 103 (10.3%) with indeterminate leprosy. Changes in the ocular bulb were noted in 314 patients (31.5%) specially in those with lepromatous leprosy. These alterations were greater with increasing age of the patient and length of disease. Severe ocular lesions were rare, probably due to previous systemic treatment. The "pearls" in the fundus of the eye resulting from leprosy were also studied.

Ocular impairments in an impairment survey of leprosy-affected persons in Nepal.

An impairment survey was carried out in Nepal. The study subjects (n = 318) were a mixture of out-patients and patients admitted less than one month before the survey. Of the subjects, 101 were attending the hospital out-patients clinic or were admitted and the rest were examined in the field. The patients studied included those on MDT and care-after-cure cases. Ocular impairments were found in 25% of these cases. The most common ocular impairment was poor vision followed by lagophthalmos and insensitive cornea.

The prevalence of disabling ocular complications of leprosy: a global study.

A world-wide study on the ocular complications of leprosy has been carried out over the past ten years. The data from 4772 patients, designed to give baseline information for a five-year incidence study, have been analysed. Blindness due to leprosy was seen in 3.2% of the sample and 7.1% had Grade 2 visual disability. The causes of visual impairment in the disease are discussed and it is emphasized that a high proportion of these are preventable, particularly through the early use of multidrug therapy. The active participation of ophthalmologists in the management of the disease is still required since many of the blinding complications respond well to surgery.

Blindness and low vision in leprosy patients in Sichuan Province, China.

The acuity of vision of 2145 leprosy patients was examined. Twenty-six patients had bilateral blindness and 80 had diminution of vision bilaterally, according to WHO's standard. The vision disability rate was 4.94%. In addition, 136 patients (6.34%) had blindness or low vision involving one eye. The causes of blindness and low vision were leukoma and corneal ulcer.

Salud ocular comunitaria: en busqueda de soluciones; primera parte / Ocular community health: in search of solutions; first part

Enfermedades como la catarata, tracoma, glaucoma, oncocercosis, xeroftalmia, degeneracion macular, retinopatia diabetica y lepra son las principales causas de ceguera en el mundo. El 93% de los ciegos estan distribuidos en Asia, Africa y Latinoamerica como resultante de las desfavorables condiciones socio-economicas, ambientales, culturales y el limitado acceso da la atencion oftalmologica de sus habitantes. De acuerdo con las estadisticas presentadas en Colombia es prioridad desarrollar un programa nacional de salud ocular, que ademas de realizar acciones para la prevencion de la ceguera, incluya la atencion adecuada de otros problemas visuales como los defectos refractivos y de patologias oculares que, a pesar de no ser causa de limitacion visual permanente, necesitan tratamiento medico o quirurgico. A nivel departamental, la Fundacion Oftalmologica de Santander -FOS, con el apoyo de organismos internacionales, avanza en la planeacion de actividades de investigacion basica y en el desarrollo de programas de prevencion y tratamiento para las poblaciones mas necesitadas