Changing pattern of childhood blindness in Saudi Arabia

Microcatheter-Assisted Circumferential Trabeculotomy After Failed Glaucoma Surgeries in Childhood Glaucoma

PURPOSE

To evaluate the outcomes of microcatheter-assisted trabeculotomy (MAT) in childhood glaucoma (primary congenital glaucoma [PCG], juvenile open-angle glaucoma [JOAG], and secondary childhood glaucoma [SCG]) after failed glaucoma surgery.

DESIGN

Retrospective interventional case series.

METHODS

Patients with childhood glaucoma who underwent MAT after failed glaucoma surgery with at least 12 months of follow-up were evaluated. Pre- and postoperative intraocular pressure (IOP) and the number of glaucoma medications were recorded and compared. Success was defined as an IOP ≤21 mm Hg with or without glaucoma medication. Analysis of variance was used to compare the glaucoma subgroups.

RESULTS

Forty-five eyes (42 patients) with a median follow-up period of 19 months were included. The median age at the time of MAT was 10 (range, 0.8-33) years. The mean number of previous surgeries was 1.3 ± 0.5. The IOP had significantly reduced from baseline in all PCG, JOAG, and SCG patients (27.9 ± 4.5 vs 16.3 ± 8.0 mm Hg, P = .001; and 30.8 ± 9.4 vs 13.5 ± 3.0 mm Hg, P < .001; and 31.5 ± 7.1 vs 16.5 ± 5.3 mm Hg, P = .001, respectively). Fewer glaucoma medications were needed after MAT in all 3 groups (each P < .001). At the last visit, the total success rates in PCG, JOAG, and SCG were 93.8%, 100%, and 88.9%, respectively. No severe complications were observed.

CONCLUSION

MAT can effectively manage PCG, JOAG, and SCG after failed surgeries, providing successful outcomes and no serious complications. Following failed glaucoma surgeries, MAT may offer these patients with childhood glaucoma an excellent opportunity to achieve IOP control.

Status of Childhood Eye Care Services in the Kingdom of Saudi Arabia: Eye Care Professionals’ Perspectives

Background:

The World Health Organization (WHO) reported that there are approximately 19 million visually impaired children worldwide, and most of the conditions are treatable by early intervention at the primary, secondary, and tertiary levels.

Objective:

To assess the status of paediatric eye care services in the Kingdom of Saudi Arabia

Methods:

A cross-sectional study was conducted among eye care professionals (optometrists and ophthalmologists) in public sector hospitals in various regions of Saudi Arabia. Data were collected through an online self-administered paediatric eye care service questionnaire based on a validated questionnaire.

Results:

A total of 137 completed questionnaires were obtained, with a response rate of 83%. The highest percentage of trained paediatric teams at hospitals was recorded at 95% in the eastern region (p= 0.024), while the lowest percentage was 44% in the southern region. Trained paediatric nurses were available in 88% of the eastern region hospitals, followed by 56% of the central region hospitals (p= 0.001). Services such as separate paediatric optometry clinics, dedicated ophthalmology outpatient clinics, and advanced diagnostic equipment were significantly higher in number in the eastern region than in the other regions (p˂0.001). The general status of human resources of eye professionals reveals that 73% of the facilities had both trained optometrists and ophthalmologists, approximately 70.8% had anaesthesiologists available, and almost 73.7% had easy access to available paediatricians.

Conclusion:

The overall quality of paediatric eye-related health care is satisfactory in most Saudi regions. However, there are some discrepancies among the regions in paediatric eye care services and facility types, which may need to be addressed by decision-makers in the Ministry of Health.

Childhood glaucoma registry in Germany: initial database, clinical care and research (pilot study)

Objective

The aim of this prospective pilot study is to establish an initial database to register patients diagnosed with different types of childhood glaucoma and the set-up of a national registry for childhood glaucoma (ReCG) in Germany. 28 children with different types of diagnosed childhood glaucoma, who were admitted and treated at the Childhood Glaucoma Center of the University Medical Center Mainz, Germany were included. Main outcome measures were the type of childhood glaucoma, mean intraocular pressure (IOP) and genetic data of the patients.

Results

The documents and questionnaires for each individual included: informed consent form of the parents, medical history form of the child, patient’s gestational history questionnaire and general anesthesia examination form. Primary congenital and secondary childhood glaucoma were revealed in 11 (39%) and 17 (61%) patients, respectively. The mean IOP measured with Perkins tonometer in all patients under general anesthesia at the time of inclusion was 17.5 ± 11.8 mmHg in the right and 17 ± 8.9 mmHg in the left eyes. In 33% of children with glaucoma mutations in the CYP1B1, FOXC1, LTBP2 and TEK genes were found. The development of specific questionnaires for childhood glaucoma provides detailed baseline data to establish a ReCG in Germany for the first time.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05921-8.

Exome sequencing identifies a novel GUCY2D mutation in an Iranian family with Leber congenital amaurosis-1: a case report

Background

Leber congenital amaurosis (LCA), the severe form of inherited retinal degenerative disorder, is a prevalent disorder in the first year of life. Recently, genetic studies discovered that different gene mutations are responsible for LCA clinical manifestations.

Case presentation

In this study, we applied whole exome sequencing (WES) to identify probable gene defects in an Iranian girl with LCA-1. We found a novel disease-causing GUCY2D gene mutation (c.2348T > C; p.L783P), located in exon 12 (NM_000180), causing a missense mutation that has been changed the coding protein. The WES-identified variant was confirmed by Sanger sequencing for the patient and her healthy parents. Submitted to genetic counseling that the patient was 1-year old and blindness from birth.

Conclusions

Our findings establish that this detected GUCY2D-p.L783P mutation is the pathogenic variant for LCA-1. This is the first genetic study indicating that c.2348T > C missense mutation in the homozygous state in GUCY2D gene is responsible for the LCA-1 phenotype.

Carrier Status for p.Gly61Glu and p.Arg368His CYP1B1 Mutations Causing Primary Congenital Glaucoma in Iran

Purpose

To estimate carrier frequencies of CYP1B1 mutations p.Gly61Glu and p.Arg368His, respectively, in Talesh and the east of Guilan province in Iran with a maximum error of 2%. Previously, it was shown that these CYP1B1 mutations may be relatively prevalent in these regions.

Methods

Population-based screenings were performed. DNA was extracted from saliva samples of 1036 individuals from Talesh and 3029 individuals from the east of Guilan. P.Gly61Glu and p.Arg368His screenings were performed, respectively, by RFLP and ARMS-based PCR protocols. For confirmation, the DNA of individuals with mutations was sequenced using the Sanger protocol.

Results

Nine individuals from Talesh (0.86%; 95%CI: 0.45–1.64%) carried the p.Gly61Glu mutation, and 73 from the east of Guilan (2.41%; 95%CI: 1.91–3.04%) carried p.Arg368His. There was no significant difference in frequencies between urban and rural regions of the various cities, nor among four cities within the east of Guilan.

Conclusion

The frequencies of p.Gly61Glu carriers in Talesh and of p.Arg368His carriers in the east of Guilan were within the 95% confidence interval of a previous study based on screenings of fewer individuals. The reliability of the recent estimates is higher, as the confidence interval for p.Gly61Glu decreased from 6.5% to 1.19% and the interval for p.Arg368His decreased from 4% to 1.13%. Based on the new findings, the maximum expected frequency of p.Gly61Glu carriers in Talesh is 1.64%, and of p.Arg368His carriers in the east of Guilan is 3%. The need for performing premarital screenings in the respective cities can be evaluated.

Pediatric Glaucoma in a University Hospital

Aims and objectives

This study aimed at describing the characteristics and outcomes of pediatric glaucoma patients in a university hospital in Lebanon and comparing them between primary congenital glaucoma (PCG) and secondary glaucoma.

Materials and methods

Sixty-four eyes of 40 pediatric glaucoma patients with a follow-up of 1 year or more were reviewed. Parameters were studied for both PCG and secondary glaucoma groups. Three major outcomes were considered: intraocular pressure (IOP) control, final best-corrected visual acuity (BCVA), and the proportion of failed angle surgeries.

Results

Sixty-four eyes were included divided into 29 PCG and 35 secondary glaucoma eyes, followed up for a mean of 6.6 ± 4.7 years. Eyes with PCG presented earlier, with a higher initial IOP and underwent earlier surgery than their secondary glaucoma counterparts. Although 85.9% of all eyes achieved good IOP control, 44.4% of them had a BCVA ≥20/50 with PCG having a better visual prognosis. Secondary glaucoma eyes needed more medications at the end of their follow-up. In this group, it was shown that a later age at first surgery, unilateral disease, and multiple surgeries were associated with a BCVA < 20/50.

Conclusion

Patients with PCG presented earlier and with a higher IOP than secondary glaucoma; they were also operated on earlier. Both groups demonstrated good IOP control at the end of the follow-up period with PCG eyes having a superior visual outcome. Secondary glaucoma eyes required a higher number of medications at their final visit. In this population, multiple surgeries, unilateral disease, and a delayed first surgery conferred a poorer visual prognosis.

Clinical significance

Data regarding the characteristics of pediatric glaucoma, especially in the Middle East, are scarce. Our study sheds the light on the presentation of different types of pediatric glaucoma and their outcomes namely IOP control and visual acuity.

How to cite this article

Dakroub M, Khair D, Noureddine B, et al. Pediatric Glaucoma in a University Hospital. J Curr Glaucoma Pract 2021;15(1):8-13.

Visual Impairment and Blindness in Saudi Arabia's School for the Blind: A Cross-Sectional Study

AIM

Visual impairment and blindness are important global health issues as they are associated with high morbidity, mortality, and decreased quality of life, leading to substantial economic loss and productivity. There are only a few published articles on vision impairment and blindness in Saudi Arabia to compare the range of estimated global prevalence of low vision, blindness, and their causes. This study aims to find out the important causes of vision impairment and blindness in schools for the blind in Qassim province, Saudi Arabia.

METHODS

The cross-sectional study was conducted at the blind schools in Buraidah city of Qassim province. A total of 278 registered cases were included in this study using a systematic random sampling of registered cases. Based on the definitions, the cases were classified as having vision impairment and/or blindness. The data were entered and analyzed using IBM SPSS 25.

RESULTS

The mean age was 30 years (range: 6 to 83 years) and 174 (76.4%) were males and 84 (32.6%) being females. The male:female ratio was 2:1. All the respondents were of Saudi ethnicity. Mild to moderate visual impairment was found in 6%, severe visual impairment in 27%, and blindness was seen in 64% of registered cases. The causes of blindness in these registered cases from blind school were retinitis pigmentosa (26%), optic atrophy (16%), glaucoma (7%), head trauma (6%), nystagmus (6%), retinopathy of prematurity (6%), ocular albinism (4%), corneal opacities (4%), amblyopia (3%) and other causes (22%). Overall, retinal disorders (retinitis pigmentosa and retinopathy of prematurity) were the leading causes of disability followed by optic atrophy.

CONCLUSION

The findings of this study are useful in planning and implementing screening programs in this area for early identification and corrections, thus preventing permanent loss of sight.

Making Blind Children See: Impact of Correcting Moderate and Severe Visual Impairment in Schools for the Blind

PURPOSE

Childhood blindness and visual impairment accounts for enormous burden of blindness. This study aimed to analyze the causes of severe visual impairment and blindness in students attending schools for the blind and to identify those whose vision could be improved by optical aids. On dispensing such aids, the study also aimed to analyze the improvement in their vision function.

METHODS

This was a prospective interventional study of 428 certified students from four special schools for blind. All the students underwent a comprehensive ophthalmic examination by a team of four ophthalmologists and four optometrists. The World Health Organization-Prevention of Blindness forms were used to record history and examination details. Spectacles and low-vision aids (LVAs) were dispensed to those whose vision could be improved. The main outcome measure was L V Prasad- Functional Vision Questionnaire (LVP-VFQ), which was used to compare the vision function before and 6 months after the intervention.

RESULTS

Two hundred and thirteen (49.5%) students were girls. The causes of blindness in 370 children (<18 years) with vision <6/60 were whole globe involvement in 117 (31.6%) students (this included anophthalmos 47 [12.7%], microphthalmos 61 [16.4%], both 9 [2.4%]), nystagmus 29 (7.8%), optic atrophy 22 (5.9%), retinal causes 42 (11.3%), cataract 18 (4.9%), phthisis bulbi 24 (6.4%), corneal scarring in 40 (10.8%), and retinopathy of prematurity in 4 (1.1%). Fifty-four (12.6%) students were given spectacles and 41 (9.57%) LVA. There was a statistically significant difference in all questions (P < 0.01) of LVP-VFQ for the students dispensed with optical aids 6 months after the intervention. Twenty-four students had their vision improved to 6/60 or better, whereas 26 could now identify letters and print.

CONCLUSION

A significant proportion of students in schools for the blind can be helped to improving vision function using optical aids. Students in schools for the blind, nay all visually impaired individuals, need periodic ocular examination and ophthalmic care.

Postural stability in people with visual impairment

BACKGROUND

The visual system enables the brain to assess information regarding the position of the body in space. Congenital or acquired blindness leads to the development of abnormal sensory-motor interactions that results in development of typical musculoskeletal deformities and gait patterns that cause disability. Diabetes and related complications are expected to increase exponentially in the next 10 years; thus, the number of people with visual impairment is expected to increase. However, there have been few studies regarding etio-pathogenesis of postural alteration and balance impairment in people with visual impairment; moreover, no previous study has investigated postural stability in this population. This study aimed to assess the center of gravity (COG) velocity in subjects with visual impairment and compared with that in sighted subjects.

METHODS

Seventy male subjects, 20-40 years of age, participated in this study; they were divided into sighted (control) and visually impaired groups. COG velocity while standing on an unstable surface was measured using the NeuroCom^® Balance Master Version 8.5.0. For the sighted group, data were recorded with eyes open and then with eyes closed. For the visually impaired group, no instructions were given with respect to eyes during data collection.

RESULTS

Mean COG velocity was significantly higher in the visually impaired group than in the sighted group with eyes open. However, there was no difference in mean COG velocity between the visually impaired group and the sighted group with eyes closed. The difference in mean COG velocity between sighted subjects with eyes open and eyes closed was also significant. Mean COG velocity while standing on a foam surface varied among visually impaired subjects and sighted subjects with eyes open and closed.

CONCLUSION

This study showed that subjects with visual impairment, regardless of eye opening or closure, behave in the same manner as sighted subjects with eyes closed.

Causes of blindness in a pediatric age group at a tertiary healthcare center in the eastern province of Saudi Arabia

Objectives:

To describe causes of blindness and visual impairment (VI) in children in Eastern province, Saudi Arabia.

Methods:

A record-based descriptive cross-sectional study was conducted. Medical records of patients aged 2 to 16 years who were following up in the Pediatric Ophthalmology Clinics, Dhahran Eye Specialist Hospital, Dhahran, Saudi Arabia between September and December 2018 were reviewed. Causes of vision loss according to visual acuity (VA) with best correction were recorded. Blindness was defined as VA <20/400, VI as VA from 20/400 to 20/60, and visual loss as VA of ≤20/60.

Results:

Of 818 patients, 39% had visual loss, 22.9% were blind, and 71.2% had VI. Common etiologies of bilateral blindness were retinal dystrophy disease and Leber’s congenital amaurosis, whereas unilateral blindness was most common due to trauma and refractive error (RE). Common etiologies of bilateral VI were RE, esotropia, and retinal dystrophy. Unilateral VI was mainly due to RE, cataract, congenital esotropia, and trauma. Of all patients, 58.8% had treatable causes, 22.6% had preventable causes, and 19.5% had non-preventable and non-treatable causes; mostly genetic or congenital (59.7%) rather than acquired (40.2%).

Conclusion:

Genetic or congenital causes are major factors causing blindness. Most causes are treatable and preventable, emphasizing on early detection and treatment of those causes.

Factors associated with early and late failure after goniotomy for primary pediatric glaucoma

Purpose:

To analyze the risk factors associated with early and late failure after goniotomy for primary pediatric glaucoma.

Methods:

A retrospective study was done on infants who underwent goniotomy as the initial surgical procedure for primary pediatric glaucoma, and had a follow-up period ⩾48 months after surgery. Early and late failures were defined as intraocular pressure ⩾18 mmHg or signs of glaucoma progression before and after the end of first year, respectively.

Results:

A total of 81 eyes of 47 children were included. The mean age at the time of surgery was 6.1 ± 6.7 months, 34 children (72.3%) were bilateral. The mean follow-up was 5.9 ± 2.8 years. Of the included eyes, 41 eyes (50.6%) showed success, 25 eyes (30.9%) showed an early failure, and 15 eyes (18.5%) showed a late failure. The mean survival time was 43 months. However, only surgery before the end of the first month and positive consanguinity of the parents (P < 0.01 for both) were independent risk factors for early and late failure of goniotomy for primary pediatric glaucoma. Patients with late failure showed a statistically significant lower preoperative intraocular pressure (P = 0.02). A larger preoperative corneal diameter and a male gender were associated with higher but statistically insignificant failure rates. There were no differences in the early or late failure rates between unilateral and bilateral cases.

Conclusion:

A positive consanguinity of the parents and surgery before the end of the first month are the major predictors of failure of goniotomy.

P.Gly61Glu and P.Arg368His Mutations in CYP1B1 that Cause Congenital Glaucoma may be Relatively Frequent in Certain Regions of Gilan Province, Iran

PURPOSE

To perform a population-based screening of four CYP1B1 mutations-p.Gly61Glu, p.Arg368His, p.Arg390His, and p.Arg469Trp-in the province of Gilan, Iran. Previous studies have shown that CYP1B1 is a cause of disease in approximately 70% of Iranian patients with primary congenital glaucoma (PCG), and that these four mutations constitute the majority of CYP1B1 mutated alleles. The carrier frequencies may even justify premarital screenings.

METHODS

DNA was extracted from the blood samples of 700 individuals recruited in a population-based epidemiology study in Gilan. Screenings were performed using polymerase chain reaction protocols based on restriction fragment length polymorphism or the amplification-refractory mutation system. For confirmation, the DNA of individuals with mutations was sequenced using the Sanger protocol.

RESULTS

Five individuals carried the p.Gly61Glu mutation, and seven carried the p.Arg368His mutation. The p.Arg390His and p.Arg469Trp mutations were not observed in any of the 700 individuals screened. The mutations were not geographically randomly distributed in Gilan; four of the p.Gly61Glu-harboring individuals were from Talesh, and six of the p.Arg368His-harboring individuals were from the eastern regions of Gilan.

CONCLUSION

The frequency of individuals who carry either p.Gly61Glu or p.Arg368His is relatively high in Gilan, and notably high in certain localities within Gilan. We suggest further screenings be performed to definitively assess the need for implementing measures to encourage screening for p.Gly61Glu and p.Arg368His before marriage in Talesh and the eastern regions of Gilan, respectively. Finally, our assessment showed that regional frequencies of CYP1B1 mutations do not necessarily mirror national frequencies.

Congenital glaucoma and CYP1B1: an old story revisited

Primary congenital glaucoma is a trabecular meshwork dysgenesis with resultant increased intraocular pressure and ocular damage. CYP1B1 mutations remain the most common identifiable genetic cause. However, important questions about the penetrance of CYP1B1-related congenital glaucoma remain unanswered. Furthermore, mutations in other genes have been described although their exact contribution and potential genetic interaction, if any, with CYP1B1 mutations are not fully explored. In this study, we employed modern genomic approaches to re-examine CYP1B1-related congenital glaucoma. A cohort of 193 patients (136 families) diagnosed with congenital glaucoma. We identified biallelic CYP1B1 mutations in 80.8% (87.5 and 66.1% in familial and sporadic cases, respectively, p < 0.0086). The large family size of the study population allowed us to systematically examine penetrance of all identified alleles. With the exception of c.1103G>A (p.R368H), previously reported pathogenic mutations were highly penetrant (91.2%). We conclude from the very low penetrance and genetic epidemiological analyses that c.1103G>A (p.R368H) is unlikely to be a disease-causing recessive mutation in congenital glaucoma as previously reported. All cases that lacked biallelic CYP1B1 mutations underwent whole exome sequencing. No mutations in LTBP2, MYOC or TEK were encountered. On the other hand, mutations were identified in genes linked to other ophthalmic phenotypes, some inclusive of glaucoma, highlighting conditions that might phenotypically overlap with primary congenital glaucoma (SLC4A4, SLC4A11, CPAMD8, and KERA). We also encountered candidate causal variants in genes not previously linked to human diseases: BCO2, TULP2, and DGKQ. Our results both expand and refine the genetic spectrum of congenital glaucoma with important clinical implications.

CYP1B1: A key regulator of redox homeostasis

CYP1B1 is a member of the CYP1 subfamily of CYP superfamily of enzymes, which contains three members, CYP1A1, CYP1A2, and CYP1B1. CYP1B1 is expressed in both adult and fetal human extrahepatic tissues, including the parenchymal and stromal cells of most organs. Mutations in the CYP1B1 gene are linked to the development of primary congenital glaucoma in humans. However, the underlying mechanisms remain unknown. Using Cyp1b1-deficient mice, we showed that CYP1B1 is constitutively expressed in retinal vascular cells with a significant role in retinal neovascularization during oxygen-induced ischemic retinopathy. We also showed CYP1B1 is constitutively expressed in trabecular meshwork (TM) cells and its expression plays a significant role in the normal development and function of the TM tissue. We have observed that germline deletion of Cyp1b1 is associated with increased oxidative stress in the retinal vascular and TM cells in culture, and retinal and TM tissue in vivo. We showed increased oxidative stress was responsible for altered production of the extracellular matrix proteins and had a significant impact on cellular integrity and function of these tissues. Collectively, our studies have established an important role for CYP1B1 expression in modulation of tissue integrity and function through the regulation of cellular redox homeostasis and extracellular microenvironment.

Primary congenital and developmental glaucomas

Glaucoma is the leading cause of irreversible blindness worldwide. Although most glaucoma patients are elderly, congenital glaucoma and glaucomas of childhood are also important causes of visual disability. Primary congenital glaucoma (PCG) is isolated, non-syndromic glaucoma that occurs in the first three years of life and is a major cause of childhood blindness. Other early-onset glaucomas may arise secondary to developmental abnormalities, such as glaucomas that occur with aniridia or as part of Axenfeld-Rieger syndrome. Congenital and childhood glaucomas have strong genetic bases and disease-causing mutations have been discovered in several genes. Mutations in three genes (CYP1B1, LTBP2, TEK) have been reported in PCG patients. Axenfeld-Rieger syndrome is caused by mutations in PITX2 or FOXC1 and aniridia is caused by PAX6 mutations. This review discusses the roles of these genes in primary congenital glaucoma and glaucomas of childhood.

Etiology of optic atrophy: a prospective observational study from Saudi Arabia

BACKGROUND

Optic atrophy (OA) represents permanent retinal ganglion cell loss warranting study to establish etiology.

OBJECTIVES

To describe neurogenic causes of OA.

DESIGN

Prospective, observational.

SETTING

Tertiary care center, Riyadh, Saudi Arabia.

PATIENTS AND METHODS

We included consecutive patients of all ages with OA caused by lesions affecting the visual pathways who were referred over a 9-month period (November 2013 to July 2014). Diagnosis was based on visual acuity, ophthalmoscopic features and ancillary tests. Patient demographics, results of a clinical examination, test data and etiology were recorded. For each cause of OA, both gender and age group were analyzed as potential risk factors using simple univariate logistic regression. OA associated with glaucoma and retinal diseases was excluded.

MAIN OUTCOME MEASURE

Description of causes of OA.

RESULTS

Two hundred and four patients and 353 eyes met inclusion criteria. The median age was 27 years (range 3 months-77 years; interquartile range, 27 years) among 111(54.4%) females and 93(45.6%) males, with no statistically significant difference in age of presentation between the genders. The majority of lesions were bilateral (n=151, 74%). Tumors were the most common cause, accounting for 127 (62.2%) cases. These occurred mostly in adults (72.4%) compared to the pediatric group (OR=3.3, 95% CI: 1.79-6.03; P < .001). Hereditary neoplasia (OR=5.55; 95% CI: 1.67-18.42; P=.005) and metabolic diseases (OR=17.57; 95% CI: 2.15-143.62; P=.007) were more common causes in the pediatric group. There were no significant associations between gender or visual acuity and etiology of OA. In developed nations, OA is frequently the result of ischemia and neuritis. We found many other causes, especially orbital and intracranial tumors.

CONCLUSIONS

The frequency of tumors as the cause of OA may represent a higher incidence of aggressive tumors coupled with poor recognition/acknowledgement of symptoms and limited access, resulting in late presentations.

LIMITATIONS

These findings may reflect bias from selective referrals to a tertiary center and may not represent all of Saudi Arabia.

Intraocular pressure and biomechanical corneal properties measure by ocular response analyser in patients with primary congenital glaucoma

PURPOSE

To measure the differences in corneal hysteresis (CH) and corneal resistance factor (CRF) in primary congenital glaucoma (PCG) and in control subjects using ocular response analyser (ORA) and also to compare intraocular pressure (IOP) measurements given by ORA against IOP given by Perkins tonometer, a handheld version of Goldman applanation tonometer (GAT), to determine correlation.

METHODS

One hundred and eighteen eyes of 78 patients with PCG (group I) and 103 eyes of 53 controls (group II) were evaluated using ORA. In all participants, IOP was measured using the Perkins tonometer. The ORA device uses applanation pressure peaks to generate the corneal-compensated IOP (IOPcc), which is reportedly independent of corneal thickness, and the measurement of Goldman-correlated IOP (IOPg), which is influenced by corneal thickness.

RESULTS

The measures in group I were as follows: IOPcc 20.92 ± 5.33; IOPg 18.87 ± 6.67; CH 8.51 ± 2.25; CRF 9.85 ± 3.03; and IOP measured by Goldman 18.32 ± 5.13. The measures in group II were as follows: IOPcc 14.33 ± 2.91; IOPg 14.77 ± 3.00; CH 11.37 ± 1.61; CRF 11.02 ± 1.74; and IOP measured by Goldman 13.74 ± 2.42. The differences of all parameters compared between both groups were statistically significant (p < 0.001 for CH and for all IOP measures and p = 0.001 for CRF). The values of IOPcc, IOPg and IOP measured with Goldman were higher in group I than the values in group II. However, CH and CRF values were lower in group I.

CONCLUSION

A decrease in CH and CRF has been observed in patients with PCG compared to controls. Future research should assess how these parameters are modified in PCG and whether they could provide more information about progression.

Causes of irreversible unilateral or bilateral blindness in the Al Baha region of the Kingdom of Saudi Arabia

Purpose

To determine the causes of irreversible unilateral and bilateral blindness that cannot be rehabilitated medically, optically nor surgically in Al Baha province, Kingdom of Saudi Arabia.

Methods

There were a retrospective chart review and examination of patients presenting to King Fahad Hospital Al Baha, Saudi Arabia, with unilateral or bilateral blindness from June 2011 to September 2011. Blindness was defined as best corrected visual acuity (BCVA) of less than 0.05 (Snellen, 20/400) or a visual field no greater than 10° around central fixation. Data were collected on patient demographics, ocular disease either primary or secondary to systemic diseases and laterality if unilateral involvement.

Results

One hundred consecutive patients were enrolled in the study. The mean age of the study sample was 58 ± 2.28 years (range, 1–90 years). The male to female ratio was 3:2. The most common cause of blindness in one or both eyes per person was diabetes (30% of patients) followed by glaucoma (23%). Reclassification of the causes of the blindness according on World Health Organization (definition of blindness which included both eyes) did not change the causes of blindness. There were 76% patients with unilateral blindness. The most common causes of unilateral blindness were diabetes mellitus (DM) (19 patients; 27%), glaucoma (17 patients; 23%) and retinal diseases (other than that caused by DM) (17 patients; 23%). In the entire study sample, the male-to-female ratio for patients with blindness from DM was 2:1. Diabetic macular edema caused 87% of the cases of blindness in patients with DM mostly in the left eye.

Conclusion

Diabetes mellitus and then glaucoma are the major causes of irreversible blindness in the Al Baha region in Saudi Arabia. Public health plans should be developed to encourage proper patient health education in the region. Additionally, effective screening should be performed at the primary health care centers for diabetes.

Surgical and Visual Outcomes of Childhood Glaucoma at a Tertiary Eye Care Center in South India

PURPOSE

This study aimed to categorize patients with childhood glaucoma into groups, study the clinical characteristics of the eyes affected, and determine the outcomes after surgery.

DESIGN

This was a retrospective, consecutive, nonrandomized study.

METHODS

Patients with childhood glaucoma who underwent planned primary trabeculectomy or combined trabeculotomy-trabeculectomy (CTT) between January 2003 and December 2008 were enrolled. Main outcome measures were intraocular pressure (IOP), visual acuity, corneal clarity, and any surgical and anesthetic complications.

RESULTS

One hundred thirty-one eyes of 81 patients were included. They were 61.7% male. Mean patient age was 6.1 ± 4.1 years, and the mean age at surgery was 35.8 ± 40.9 months. Postoperatively, the improvement in visual acuity was highly statistically significant at all follow-ups (P < 0.001). The IOP values showed a significant reduction from 29.2 ± 9.7 mm Hg preoperatively to 13.7 ± 5.3 mm Hg (P < 0.001) at 6-month follow-up and 12.1 ± 2.2 mm Hg at last follow-up. Cumulative corneal clarity improved significantly postoperatively (P < 0.001). A comparison of trabeculectomy alone and CTT showed that both procedures were quite effective. At 1 year, overall complete success was seen in 73.3%, qualified success in 16.8%, and failure in 10.7%.

CONCLUSIONS

This study suggests that CTT is safe and effective in both primary and secondary childhood glaucomas. Trabeculectomy alone is also highly effective in certain cases, and proper case selection is essential to attain optimum results. Surgical intervention leads to improvement in vision and corneal clarity and also achieves long-term IOP control.

Trends in the incidence and causes of severe visual impairment and blindness in children from Israel

PURPOSE

To describe trends in the incidence and causes of legal childhood blindness in Israel, one of the few countries worldwide that maintain a national registry of the blind.

METHODS

We performed a historical cohort study of annual reports of the National Registry of the Blind (NRB) between 1999 and 2013. All data regarding demographic information, year of registration and cause of blindness of children 0-18 years of age registered for blind certification were obtained from the annual reports of the NRB. Causes of legal blindness analyzed were optic atrophy, retinitis pigmentosa, retinopathy of prematurity (ROP), albinism, other retinal disorders, cataract, and glaucoma. The main outcome measure was the incidence of new cases of certified legal blindness.

RESULTS

The incidence of newly registered legally blind children in Israel almost halved from 7.7 per 100,000 in 1999 to 3.1 per 100,000 in 2013. The decline was mainly attributable to a decreased incidence of blindness resulting from retinitis pigmentosa and ROP. The incidence of registered cases due to cerebral visual impairment increased.

CONCLUSIONS

During the past decade the incidence of severe childhood visual impairment and blindness declined in Israel. A continuous decline in consanguineous marriages among the Jewish and Arab populations in Israel may have contributed to the decrease in the rate of vision loss due to retinitis pigmentosa in children.

Prevalence of selected congenital anomalies in Saudi children: a community-based study

BACKGROUND AND OBJECTIVES

Limited data are available on the prevalence of congenital anomalies based on a community survey in Middle East countries. The prevalence of congenital anomalies is expected to be high in these countries because of the high consanguinity rate and high maternal age. The aim of this cross-sectional study was to establish the prevalence of congenital anomalies in Saudi Arab children.

DESIGN AND SETTINGS

This is a prospective, cross-sectional, community-based study conducted over 2 years among the Saudi population.

SUBJECTS AND METHODS

The study sample was determined by a multi-stage probability random sampling of household representatives of the Saudi Arab population. The health status of children was obtained during household visits by primary care physicians who performed a history and physical examination of all children and adolescents younger than 19 years. All cases of congenital anomalies were recorded.

RESULTS

During the 2-year study period (2004-2005), a total of 45 682 children were screened. The commonest congenital anomalies found in this survey were Down syndrome, congenital deafness, and congenital blindness with prevalence rates of 6.6 per 10 000, 4.8 per 10000, and 1.3 per 10000 children, respectively. The prevalence of cleft lip with or without cleft palate was 0.9 per 10000 children, achondroplasia was 0.7 per 10000, and Dandy-Walker syndrome was 0.4 per 10000. Crouzon syndrome, Treacher-Collins syndrome, Angelman syndrome, and Turner syndrome had equal prevalence of 0.2 per 10000 children.

CONCLUSION

The data suggest a significant decline in the prevalence of Down syndrome; however, the prevalence of other anomalies like congenital deafness is still high.

Individualized medicine enabled by genomics in Saudi Arabia

The biomedical research sector in Saudi Arabia has recently received special attention from the government, which is currently supporting research aimed at improving the understanding and treatment of common diseases afflicting Saudi Arabian society. To build capacity for research and training, a number of centres of excellence were established in different areas of the country. Among these, is the Centre of Excellence in Genomic Medicine Research (CEGMR) at King Abdulaziz University, Jeddah, with its internationally ranked and highly productive team performing translational research in the area of individualized medicine. Here, we present a panorama of the recent trends in different areas of biomedical research in Saudi Arabia drawing from our vision of where genomics will have maximal impact in the Kingdom of Saudi Arabia. We describe advances in a number of research areas including; congenital malformations, infertility, consanguinity and pre-implantation genetic diagnosis, cancer and genomic classifications in Saudi Arabia, epigenetic explanations of idiopathic disease, and pharmacogenomics and personalized medicine. We conclude that CEGMR will continue to play a pivotal role in advances in the field of genomics and research in this area is facing a number of challenges including generating high quality control data from Saudi population and policies for using these data need to comply with the international set up.

Assessment of peripapillary retinal nerve fiber layer thickness using scanning laser polarimetry (GDx VCC) in normal Indian children

Purpose:

To obtain reference values of RNFL thickness in normal Indian children and to study the association of RNFL thickness with central corneal thickness(CCT) and axial length(AL).

Materials and Methods:

200 normal Indian children (mean age 8.6 ± 2.9 yrs) were examined on the GDxVCC. The inferior average (IA), superior average (SA), temporal-superior-nasal-inferior-temporal (TSNIT) average and nerve fiber index (NFI) values were recorded and compared between males and females as well as between the different age groups. The association of TSNIT average with AL and CCT was examined.

Results:

Values for the RNFL parameters were-SA: 64.9 ± 9.7, IA: 63.8 ± 8.8, TSNIT average: 53.5 ± 7.7 and NFI 21.5 ± 10.8. Superior, inferior and TSNIT averages did not differ significantly between males and females (P = 0.25, P = 0.19, P = 0.06 respectively; Mann-Whitney U test). No significant differences were found in TSNIT average across age groups. There was a statistically significant positive correlation between CCT and TSNIT average (r = 0.25, r² = 0.06, P < 0.001). The correlation TSNIT average and AL(r = −0.12; r² = 0.01) was not significant (P = 0.2).

Conclusion:

Reference values for RNFL parameters reported for Indian children are similar those reported in adults. There is a small correlation between central corneal thickness and RNFL as reflected in average TSNIT.

Genes associated with retinitis pigmentosa and allied diseases are frequently mutated in the general population

BACKGROUND

Retinitis pigmentosa and other hereditary retinal degenerations (HRD) are rare genetic diseases leading to progressive blindness. Recessive HRD are caused by mutations in more than 100 different genes. Laws of population genetics predict that, on a purely theoretical ground, such a high number of genes should translate into an extremely elevated frequency of unaffected carriers of mutations. In this study we estimate the proportion of these individuals within the general population, via the analyses of data from whole-genome sequencing.

METHODOLOGY/PRINCIPAL FINDINGS

We screened complete and high-quality genome sequences from 46 control individuals from various world populations for HRD mutations, using bioinformatic tools developed in-house. All mutations detected in silico were validated by Sanger sequencing. We identified clear-cut, null recessive HRD mutations in 10 out of the 46 unaffected individuals analyzed (∼22%).

CONCLUSIONS/SIGNIFICANCE

Based on our data, approximately one in 4-5 individuals from the general population may be a carrier of null mutations that are responsible for HRD. This would be the highest mutation carrier frequency so far measured for a class of Mendelian disorders, especially considering that missenses and other forms of pathogenic changes were not included in our assessment. Among other things, our results indicate that the risk for a consanguineous couple of generating a child with a blinding disease is particularly high, compared to other genetic conditions.

Magnitude and Causes of Low Vision Disability (Moderate and Severe Visual Impairment) among Students of Al-Noor Institute for the Blind in Al-Hassa, Saudi Arabia: A case series

OBJECTIVES

This study aimed to estimate the magnitude and causes of low vision disability (severe visual impairment [SVI] and moderate visual impairment [MVI]) among students at Al-Noor Institute for the Blind (NIB) in Al-Hassa, Saudi Arabia in 2006.

METHODS

An optometrist conducted refraction of 122 eyes of the 61 students (27 boys and 34 girls) with MVI (vision <6/18 to 6/60) and SVI (vision <6/60 to 3/60). Ophthalmologists examined the anterior and posterior segments, and analysed the outcomes of additional investigations to finalise the diagnosis. The results were categorised as 'preventable', 'treatable' and 'not amenable to treatment'. The low vision care was also reviewed.

RESULTS

In 12 (9.8%) eyes, visual acuity was ≥6/18 and in 28 (23%) eyes, it was <3/60. MVI and SVI were found in 82 eyes (67.2%). Hereditary retinal disorders were found in 68 (55.7%) eyes. Although refractive errors were found in 112 (91.8%) eyes, isolated refractive error was found in only 9 students. Congenital glaucoma and cataract were responsible for visual impairment in 16 (13.1%) and 9 (7.4%) eyes. These students were prescribed optical and non-optical low vision aids.

CONCLUSION

Retinal disease was the main cause of SVI and MVI in our series. Some students at Al-Noor Institute for the Blind have curable low vision conditions. Rehabilitation of low vision disability should be different from that offered to the absolutely blind.

Changing pattern of childhood blindness in Maharashtra, India

AIM

To determine the causes of severe visual impairment and blindness in children in schools for the blind in Maharashtra, India.

METHODS

Children aged <16 years with a visual acuity of <6/60 in the better eye, attending 35 schools for the blind were examined between 2002 and 2005, and causes were classified using the World Health Organization's system.

RESULTS

1985 students were examined, 1778 of whom fulfilled the eligibility criteria. The major causes of visual loss were congenital anomalies (microphthalmos or anophthalmos; 735, 41.3%), corneal conditions (mainly scarring; 395, 22.2%), cataract or aphakia (n = 107, 6%), and retinal disorders (mainly dystrophies; n = 199, 11.2%). More than one third of children (34.5%) were blind from conditions which could have been prevented or treated, 139 of whom were referred for surgery. Low vision devices improved near-acuity in 79 (4.4%) children, and 72 (4%) benefited from refraction. No variation in causes by sex or region was observed.

CONCLUSIONS

Congenital anomalies accounted for 41% of blindness, which is higher than in a similar study conducted 10 years ago. Corneal scarring seems to be declining in importance, low vision and optical services need to be improved, and research is needed to determine the aetiology of congenital anomalies.

Childhood blindness at a school for the blind in Riyadh, Saudi Arabia

PURPOSE

To determine the major causes of eye diseases leading to visual loss and blindness among children attending a school for the blind in Riyadh, Saudi Arabia.

METHODS

A total of 217 school children with visual disabilities attending a school for the blind in Riyadh were included. All children were brought to The Eye Center, Riyadh, and had complete ophthalmologic examinations including visual acuity testing, biomicroscopy, ophthalmoscopy, tonometry and laboratory investigations. In addition, some patients were subjected to electroretinography (ERG), electrooculography (EOG), measurement of visual evoked potentials (VEP), and laboratory work-up for congenital disorders.

RESULTS

There were 117 male students with an age range of 6-19 years and a mean age of 16 years. In addition, there were 100 females with an age range of 6-18 years and a mean age of 12 years. Of the 217 children, 194 (89%) were blind from genetically determined diseases or congenital disorders and 23 (11%) were blind from acquired diseases. The major causes of bilateral blindness in children were retinal degeneration, congenital glaucoma, and optic atrophy. The most common acquired causes of childhood blindness were infections and trauma.

CONCLUSION

The etiological pattern of childhood blindness in Saudi Arabia has changed from microbial keratitis to genetically determined diseases of the retina and optic nerve. Currently, the most common causes of childhood blindness are genetically determined causes. Consanguineous marriages may account for the autosomal recessive disorders. Public education programs should include information for the prevention of trauma and genetic counseling. Eye examinations for preschool and school children are mandatory for the prevention and cure of blinding disorders.

Correlation between surgical success rate and severity of congenital glaucoma

AIM

To study the correlation between severity of primary congenital glaucoma (PCG) and success of three types of surgery.

METHODS

This was a retrospective review of all records of patients diagnosed with PCG up to age 1 year who underwent goniotomy, trabeculotomy, or combined trabeculotomy-trabeculectomy with mitomycin C as initial procedure between 1982 and 2002 at the King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia. 532 paediatric glaucoma patients below age 1 year (820 eyes) with a minimum 1 year follow up were identified. The main outcome measures used for the surgeries were postoperative intraocular pressure, stability of the corneal diameter, and maintenance of corneal clarity. Surgical success was defined as a postoperative intraocular pressure of < or = 21 mm Hg without additional medical or surgical therapy, and with decreased corneal oedema, stabilised corneal diameter, and no additional optic nerve damage for at least 1 year after surgery. Complications, time of surgical failure, and follow up were recorded.

RESULTS

The eyes were grouped into mild (249), moderate (342), and severe (229) PCG, based on intraocular pressure, corneal diameter, and clarity. All three surgical procedures resulted in high success rates of 81-100% for the mild form of PCG. Eyes classified with moderate glaucoma had a 13%, 40%, and 80% success rate respectively for goniotomy, trabeculotomy, and combined trabeculotomy-trabeculectomy with mitomycin C. The success rate for severe PCG was 10% and 70% for trabeculotomy and combined surgery respectively. Goniotomy was never done for eyes with this condition.

CONCLUSION

Clinical classification of PCG is helpful for surgical decision making. The mild form has a high surgical success regardless of the procedure chosen. Combined trabeculotomy-trabeculectomy with mitomycin C gave the best results for moderate and severe cases of PCG.

Pattern of childhood blindness at a referral center in Saudi Arabia

BACKGROUND

An understanding of the causes of blindness and the magnitude of the problem is crucial in designing effective intervention and prevention programs. We undertook this retrospective review to determine the causes of childhood blindness at an eye referral center.

PATIENTS AND METHODS

We reviewed charts of children who presented between August 1997 and August 2003. All children had a complete ophthalmologic examination. Blindness was defined as a visual acuity < 20/400, visual impairment as visual acuity between 20/400 and 20/60, and visual loss as a visual acuity < 20/60.

RESULTS

A total of 5217 children included 220 (59%) males and 152 (41%) females (age range 2 to 18 years, mean age, 10 years). One hundred twelve (2%) were blind and 260 (5%) had visual impairment. The most common causes of bilateral blindness included optic nerve diseases, retinal disorders, and cataract. The most common causes of unilateral blindness included trauma, retinal diseases, refractive errors, and optic nerve diseases. The most common causes of bilateral visual impairment included refractive errors, corneal diseases, retinal disorders, cataract, and congenital nystagmus. Genetically determined disorders were observed in 37 (70%) of 53 patients with bilateral blindness, and in 52 (56%) of 93 patients with bilateral visual impairment. The incidence of consanguinity among parents of children with acquired causes was 2 (3%) of 59 patients compared to 34 (38%) of 89 among genetically determined causes (P < 0.001).

CONCLUSION

Genetically determined disorders continue to play an important role in the causation of childhood blindness among patients attending our referral center in Saudi Arabia. Genetic counseling, early eye screening of children and public education may help in the prevention of visual disorders in children.

Causes of blindness at the "Wiyata Guna" School for the Blind, Indonesia

AIM

To determine the anatomical site and patterns of cause of blindness in one of the biggest schools for the blind in Indonesia with a view to determining potentially preventable and treatable causes.

METHODS

165 students in one school for the blind in Bandung, Indonesia, were examined clinically and data reported using the WHO/PBL childhood blindness assessment form.

RESULTS

Most of the students (96.4%) were blind (BL); 3% were severely visually impaired (SVI). The major causes of SVI/BL in this study were: (1) corneal staphyloma, corneal scar, and phthisis bulbi (mainly attributed to infection) in 29.7%; (2) retinal dystrophies (mainly Leber congenital amaurosis, early onset retinitis pigmentosa) in 20.6%; (3) congenital and familial cataract (13.3%); (4) microphthalmus, anophthalmus (10.9%). The whole globe was the major anatomical site of visual loss (32.7%), followed by the retina (26.0%), cornea (17.6%), lens (13.3%), optic nerve (6.1%), and uvea (4.3%).

CONCLUSIONS

This is a small study in a selected population and the results should be interpreted with caution. This blind school study, adopting the WHO/PBL eye form for data analysing, is the first reported for Indonesia. Hereditary disease and infective causes of blindness are the predominant causes of blindness, accounting for 42.4% and 29.7%, respectively. This pattern of causes is a mixed pattern which lies in an intermediate position between the patterns seen in developing countries and those seen in developed countries. The importance both of preventive public health strategies and of specialist paediatric ophthalmic and optical services in the management of childhood blindness in Indonesia are therefore strongly suggested to cover the problems that exist.

Penetrating keratoplasty in young children with congenital hereditary endothelial dystrophy

PURPOSE

To report the visual results and success rate of penetrating keratoplasty (PKP) in a series of young children with congenital hereditary endothelial dystrophy (CHED).

METHODS

This is a retrospective study on twenty-four eyes of 15 patients (seven male and eight female) operated on for CHED. Children less than 12 years of age at the time of surgery who were followed for at least 6 months were recalled. Characteristics of the patients, indications for PKP, final visual outcome, and graft clarity were evaluated. The following tests were employed: McNemmar test for evaluating visual results, Kaplan-Meyer analysis for determination of graft survival, and Mann-Whitney U test for evaluating the relationship between visual outcome and age at PKP.

RESULTS

Patients' age at diagnosis and at initial PKP was 6.5 +/- 3.6 and 8.1 +/- 2.5 years, respectively. Follow-up period was 35.5 +/- 36.2 months. Visual acuity could be evaluated by Snellen chart in 19 eyes. Preoperative visual acuity was less than 20/80 in all of these. Postoperatively, visual acuity was less than 20/80 in nine eyes (47.4%) (P < 0.002). Visual acuity improved in 18 (94.7%) of 19 eyes. There was no relationship between age at initial PKP and final visual outcome (P = 0.35). At the last examination (24 grafts), 19 were clear (79.1%), two were hazy (8.3%), and three were opaque (12.5%). Allograft rejection was seen in 10 eyes (43.4%), seven of which were endothelial. Excluding one case of trauma, all graft failures resulted from endothelial rejection. The probability of primary graft survival was 88% at 3 years and 74% at 5 years.

CONCLUSION

Regarding the difficulties in pediatric keratoplasty and the absence of a relationship between postoperative visual outcome and age at keratoplasty, a conservative approach and careful risk-benefit ratio evaluation are recommended in patients with CHED.

Causes of childhood blindness in Malaysia: results from a national study of blind school students

A national study was conducted in children attending six schools for the blind in Malaysia to identify the anatomical site and underlying causes of blindness (BL) and severe visual impairment (SVI), with a view to determine the potentially preventable and treatable causes so that appropriate control measures can be implemented in the future. The standardized clinical examination of eyes was performed and the findings were recorded on the WHO Prevention of Blindness Programme eye examination record form for children with blindness and low vision. A total of 358 children aged between 7 and 17 years were examined, of whom 332 (92.7%) were blind or severely visually impaired. The results relate to these 332 children. Lens was the major anatomical site (22.3%) of visual loss followed by retina (20.8%), whole globe (17.2%), cornea (15.1%), optic nerve (8.7%) and uvea (5.1%). Glaucoma was responsible for BL/SVI in 7.2% and others in 3.6% of cases. Hereditary diseases were responsible for visual loss in 29.5%, intrauterine factors in 4.5%, perinatal factors in 9% and childhood factors in 7.8% of cases. However, the aetiology was unknown in 49.1% of cases which included congenital anomalies of the globe. Childhood cataract and corneal scarring are major treatable causes of BL/SVI that can benefit from future intervention strategies. Perinatal screening for intrauterine factors and hereditary eye diseases, and appropriate interventional therapy will help in reducing the prevalence of childhood blindness.

Causes of blindness among adult Jordanians: a hospital-based study

PURPOSE

To assess the causes of blindness among adults aged 20 years and over who attended two big general ophthalmic clinics in Jordan.

PATIENTS AND METHODS

This hospital-based study was undertaken at Jordan University Hospital in Amman (the capital of Jordan) and Princess Basma Teaching Hospital which is affiliated with Jordan University of Science and Technology in Irbid, the third largest city in the country. A total of 2732 patients seen consecutively over 26 months were examined and the ophthalmic findings were recorded. Using standard Snellen charts, subjects were placed in one of three categories according to their best corrected visual acuity: (1) unilateral blindness: less than 6/60 in the worst eye, 6/60 or more in the better eye; (2) moderate bilateral blindness: less than 6/60 in the worst eye, less than 6/60 to 3/60 or more the better eye; and (3) severe bilateral blindness: less than 3/60 in both eyes.

RESULTS

Of the totalpatients seen, 373 were blind according to the selection criteria. Among 248 patients with unilateral blindness, diabetic retinopathy, cataract and trauma were the leading causes. Among the 81 patients with moderate bilateral blindness, diabetic retinopathy and cataract were the leading causes. Diabetic retinopathy and glaucoma were the leading causes in patients with severe bilateral blindness.

CONCLUSIONS

These data could be used in planning blindness prevention and treatment programs while awaiting a national survey on the prevalence and causes of blindness in Jordan.

Childhood blindness and visual loss: an assessment at two institutions including a "new" cause

PURPOSE

This study was initiated to investigate the causes of childhood blindness and visual impairment in the United States. We also sought a particular etiology--congenital lymphocytic choriomeningitis virus (LCMV)--which has been considered exceedingly rare, in a fixed target population of children, the severely mentally retarded.

METHODS

We undertook a library-based study of the world literature to shed light on the causes of childhood blindness internationally and to put our data in context. We prospectively examined all consented children (159) at 2 institutions in the United States to determine their ocular status and the etiology of any visual loss present. One of the institutions is a school for the visually impaired (hereafter referred to as Location V), in which most of the students have normal mentation. The other is a home for severely mentally retarded, nonambulatory children (hereafter referred to as Location M). This institution was selected specifically to provide a sample of visual loss associated with severe retardation because the handful of cases of LCMV in the literature have been associated with severe central nervous system insults. Histories were obtained from records on site, and all children received a complete cyclopleged ophthalmic examination at their institution performed by the author. Patients at Location M with chorioretinal scars consistent with intrauterine infection (a possible sign of LCMV) had separate consents for blood drawing. Sera was obtained and sent for standard TORCHS titers, toxoplasmosis titers (Jack S. Remington, MD, Palo Alto, Calif), and ELISA testing for LCMV (Centers for Disease Control and Prevention, Atlanta, Ga).

RESULTS

The diagnoses at Location V were varied and included retinopathy of prematurity (19.4%), optic atrophy (19.4%), retinitis pigmentosa (14.5%), optic nerve hypoplasia (12.9%), cataracts (8.1%), foveal hypoplasia (8.1%), persistent hyperplastic primary vitreous (4.8%), and microphthalmos (3.2%). The most common diagnosis at Location M was bilateral optic atrophy, which was found in 65% of the patients examined who had visual loss. Of these, the insults were most often congenital (42.6%), with birth trauma, prematurity, and genetics each responsible for about 15% of the optic atrophy. The second most common diagnosis was cortical visual impairment (24%), followed by chorioretinal scars (5%), which are strongly suggestive of intrauterine infection. Of 95 patients examined at Location M, 4 had chorioretinal scars. Two of these had dramatically elevated titers for LCMV, as did one of their mothers. One of the other 2 children died before serum could be drawn, and the fourth had negative titers for both TORCHS and LCMV.

CONCLUSIONS

At both locations studied, visual loss was most often due to congenital insults, whether genetic or simply prenatal. The visual loss at Location V was twice as likely as that at Location M to be caused by a genetic disorder. The genetic disorders at Location V were more often isolated eye diseases, while those among the severely retarded at Location M were more generalized genetic disorders. Our study identified optic atrophy as a common diagnosis among the severely mentally retarded with vision loss, a finding that is supported by previous studies in other countries. In our population of severely retarded children, the target etiology of lymphocytic choriomeningitis virus was responsible for half the visual loss secondary to chorioretinitis from intrauterine infection. This is more common than would be predicted by the few cases previously described in the literature, and strongly suggests that LCMV may be a more common cause of visual loss than previously appreciated. We believe that serology for LCMV should be part of the workup for congenital chorioretinitis, especially if the TORCHS titers are negative, and that perhaps the mnemonic should be revised to "TORCHS + L." Childhood blindness and visual impairment are tragic and co

Visual impairment in Swedish children. III. Diagnoses

PURPOSE

To gain an overview of the spectrum of diagnoses among Swedish visually impaired children.

METHODS

An epidemiological study of all known visually impaired children was made by review of medical records.

RESULTS AND CONCLUSION

In all we found 2373 children, 0-19 years of age, with an age-specific prevalence of 10.9/10,000. The two largest diagnostic groups included neuro-ophthalmological and retinal diseases. The most frequent disorders were cerebral visual impairment, non-hereditary optic atrophy, retinal dystrophy (when regarded as a general entity), congenital hypoplasia of the optic nerve and congenital cataract. Nystagmus secondary to brain disorder, albinism, congenital nystagmus, retinopathy of prematurity and high myopia were also found in a considerable number of patients. The leading diagnoses in children with WHO-defined childhood blindness were non-hereditary optic atrophy, cerebral visual impairment and retinopathy of prematurity. A large proportion of the children, especially in the groups with neuro-ophthalmological disorders and malformations of the posterior segment had additional impairments, emphasizing the importance of a multi-disciplinary approach when assessing multi-handicapped children.

The importance of prenatal factors in childhood blindness in India

The causes of visual loss in 1411 children attending schools for the blind in different geographical areas in India are described. Ninety-three percent (1318) of the children were severely visually impaired (SVI) or blind (i.e. corrected acuity in the better eye of <20/200 [<6/60]). In 60% of SVI/blind children vision loss was attributable to factors operating in the prenatal period, in 47% the prenatal factors were known and definite, and in 13% prenatal factors were the most probable causes. Hereditary retinal dystrophies and albinism were seen in 19% of SVI/blind children and 23% had congenital ocular anomalies. There were variations in the relative importance of different causes by state. The observed pattern of causes of visual loss is intermediate between those seen in industrialised countries and in the poorest developing countries. This suggests that strategies to combat childhood blindness in India need to address concurrently both preventable and treatable causes. The need for aetiological studies, particularly on anophthalmos and microphthalmos, is highlighted.

Penetrating keratoplasty in congenital hereditary endothelial dystrophy

PURPOSE

The purpose of the study is to determine the outcome of penetrating keratoplasty in congenital hereditary endothelial dystrophy.

METHODS

Records of 40 patients (13 males, 27 females) who underwent penetrating keratoplasty (56 eyes) were reviewed. The mean age at surgery was 11.8 years (range, 2 months-35 years). The mean follow-up was 37 months (range, 6-136 months).

RESULTS

In 35 (62.5%) of 56 eyes that underwent primary penetrating keratoplasty, the grafts survived. Graft survival analysis showed the probability of obtaining a clear graft is 92% at 1 year, 72% at 2 years, and 56.5% at 5 years. Graft survival was statistically better in eyes where onset of the disease is delayed (P = 0.02), if the graft donor age is between 5 and 30 years versus older than 30 years (P = 0.02), and for patients who kept follow-up appointments versus those who were delinquent (P < 0.03). Visual acuity was 20/40 in 1.9%, 20/50 to 20/80 in 18.9%, 20/100 to 20/300 in 49%, and less than 20/400 in 30.2%. The main causes of graft failure were graft rejection (six eyes) and bacterial keratitis (four eyes).

CONCLUSIONS

Penetrating keratoplasty in congenital hereditary endothelial dystrophy is moderately successful, and graft survival is better in cases of delayed onset compared with that of congenital onset. Early surgical intervention is recommended to prevent development or progression of amblyopia.

Visual impairment in Swedish children. II. Etiological factors

The analysis of etiological factors in a group of visually impaired children is of considerable importance when trying to find guidelines for possible preventive work. In this study we present etiological data on 2373 Swedish children. Data have been obtained by reviewing medical records on all known children with visual impairment throughout the country. In accordance with similar studies from industrialised countries, the group with prenatal etiology was the predominant, comprising 64% of the material. Within this group, half the patients had a disease of genetic origin. A total of 50% of all patients with prenatal etiology had an additional impairment, but in the group with diseases of genetic origin this proportion was smaller, only 40%. On the other hand, many children with additional impairments were found among those with an unspecified prenatal influence. Peri-/neonatal etiologies were found in 20% of the patients. In this group as many as 83% had additional impairments. This was even more pronounced among children delivered at term. The group with infantile/juvenile etiologies was small, 7%, with additional impairments in 66%. In 9% of all patients the etiology was classified as unknown. Among these, 80% had additional impairments. The visual impairment tended to be more pronounced, the later the disease was acquired. A male preponderance was seen in most etiological subgroups and in the material as a whole.

Epidemiology of cataract in childhood: a global perspective

Cataract is the most important cause of treatable childhood blindness. There are an estimated 200,000 children blind from cataract worldwide; 20,000 to 40,000 children with developmental bilateral cataract are born each year. Rubella is still an important cause of preventable disease in many countries. In the developing world, there is a need to improve early case detection and referral services and to establish centers with expertise in the assessment, surgical treatment, and long-term management of the child with cataract.

Causes of blindness in Irbid, Jordan

To determine the most common causes of blindness and the age of onset of these conditions among Jordanians of Irbid, a study of all registered members in two societies for the care of the blind was carried out. Of all registered members, 185 individuals were blind according to the World Health Organization definition and satisfied our inclusion criteria. It was found that genetically determined causes made up 41% of the total causes. In 57% of the subjects, blindness occurred in the first two decades of life. The specific leading causes of blindness, in the order of their frequencies, were tapetoretinal degenerations as different variants of retinitis pigmentosa (17.6%), glaucomas (16%), diabetic retinopathy (13%), post-infection corneal scarring (11.5%), congenital cataract (8.8%) and uveitis (8%). The results reflect the satisfactory achievements in primary health care levels and the challenge to make specialized tertiary health care more accessible.

Infantile cataracts

Cataracts are one of the most treatable causes of visual impairment during infancy. Recent epidemiological studies have shown that they have a prevalence of 1.2 to 6.0 cases per 10,000 infants. The morphology of infantile cataracts can be helpful in establishing their etiology and prognosis. Early surgery and optical correction have resulted in an improved outcome for infants with either unilateral or bilateral cataracts. While contact lenses continue to be the standard means of optically correcting an infant's eyes after cataract surgery, intraocular lenses are gaining in popularity as an alternative means of optically correcting these eyes. Post-operative complications occur more commonly after infantile than adult cataract surgery and many of these complications do not develop until years later. As a result, it is critical that children be followed closely on a long term basis after infantile cataract surgery.

Hereditary disease as a cause of childhood blindness: regional variation. Results of blind school studies undertaken in countries of Latin America, Asia and Africa

There is evidence from developed countries that genetic disease is the major cause of childhood blindness. Little data are available from most developing and newly industrialised countries concerning the relative importance of hereditary diseases as a cause of childhood blindness. Children in schools for the blind in 13 countries of Africa, Latin America and Asia were examined between 1990 and 1994 using a standardised method The anatomical site of abnormality and underlying aetiology were analysed for children with a corrected acuity in the better eye of less than 6/60 (severe visual impairment and blindness, svi/BL). In these countries II-39% of svi/BL was attributed to genetic disease. Genetic diseases were responsible for a higher proportion of childhood visual loss in countries with higher levels of socio-economic development. An autosomal recessive mode of inheritance was reported in 22-52% of children with genetic disease. Retinal dystrophies were the commonest form of genetic eye disease (49-80%) in all countries apart from Thailand and the Philippines where cataract was the commonest (43.9%). The role of consanguinity, and opportunities for further research are discussed.