Consanguinity and Eye Diseases with a Potential Genetic Etiology. Data from a Prevalence Study in Andhra Pradesh, India

PURPOSE

To determine the prevalence of consanguinity and its potential associations with eye diseases in Andhra Pradesh state of south India.

METHODS

As part of a demographic interview schedule, prior to clinical examinations, trained investigators collected information regarding consanguinity of the parents from subjects randomly chosen for a population-based cross-sectional epidemiological study. Each subject underwent a detailed ocular examination including visual acuity measurements, anterior segment examinations with slit-lamp biomicroscopy, and posterior segment examinations. Adjusted odds ratios (OR), attributable risks (AR) and population attributable risks (PAR) were estimated.

RESULTS

We obtained details regarding consanguinity of the parents from 10,290 of the 10,293 subjects who were enumerated and examined in the study. Parental consanguinity was reported by 1822 (24.7%) rural subjects and 782 (32.9%) urban subjects. Eighty (0.008%, 95% CI: 0.006, 0.010) of the 9757 subjects had an ocular disease with a potential genetic basis. We found microcornea to be significantly associated with both an uncle-niece relationship (adjusted OR: 7.32, 95% CI: 1.73, 30.97, AR = 86.34%, PAR = 42.11%) and a first-cousin relationship between the parents (adjusted OR 4.51, 95% CI: 1.05, 19.40, AR = 77.83%, PAR = 29.02%). Retinitis pigmentosa was significantly associated with a first-cousin relationship between the parents (adjusted OR: 5.31, 95% CI: 1.00, 28.25, AR = 81.17%, PAR = 33.43%).

CONCLUSIONS

The high prevalence of consanguinity in this population does not appear to translate into a high prevalence of ocular malformations; however, studies with larger sample sizes are required to further explore the strength of these associations.

Risk factors for diabetic retinopathy: Findings from The Andhra Pradesh Eye Disease Study

OBJECTIVE

To assess prevalence, potential risk factors and population attributable risk percentage (PAR%) for diabetic retinopathy (DR) in the Indian state of Andhra Pradesh.

METHODS

A population-based study, using a stratified, random, cluster, systematic sampling strategy, was conducted in the state of Andhra Pradesh in India during 1996 and 2000. Participants from 94 clusters in one urban and three rural areas representative of the population of Andhra Pradesh, underwent a detailed interview and a comprehensive dilated ocular evaluation by trained professionals. DR was defined according to the international classification and grading system. For subjects more than or equal to 30 years of age, we explored associations of DR with potential risk factors using bivariable and multivariable analyses. Population attributable risk percent was calculated using Levin's formula.

RESULTS

Diabetic retinopathy was present in 39 of 5586 subjects, an age-gender-area-adjusted prevalence of 0.72% (95% confidence interval (CI): 0.49%-0.93%) among subjects aged >/= 30 years old, and 0.27% (95% CI: 0.17%-0.37%) for all ages. Most of the DR was either mild (51.3%) or moderate (35.9%) non-proliferative type; one subject (2.6%) had proliferative retinopathy. Multivariable analysis showed that increasing age, adjusted odds ratio (OR); 4.04 (95% CI: 1.88-8.68), middle and upper socioeconomic status group (OR); 2.34 (95% CI: 1.16-4.73), hypertension (OR); 3.48 (95% CI: 1.50-8.11) and duration of diabetes >/= 15 years (OR); 8.62 (95% CI: 2.63-28.29) were significantly associated with increasing risk of DR. The PAR % for hypertension was 50%; it was 10% for cigarette smokers.

CONCLUSIONS

Extrapolating the prevalence of diabetic retinopathy in our sample to the Indian population suggests that there may be an estimated 2.77 million people with DR, approximately 0.07 million people with severe DR. As the population demographics change towards aging, this number is likely to increase further. Health care programs in India need to examine strategies to prevent diabetes and DR, as well as create the infrastructure required to manage this condition.

Relationship between Visual Impairment and Eye Diseases and Visual Function in Andhra Pradesh

OBJECTIVE

To determine the impact of visual impairment and eye diseases on visual function in an older population of Andhra Pradesh in southern India.

DESIGN

Population-based cross-sectional study.

PARTICIPANTS

The visual function questionnaire (VFQ) was completed by 7363 (99.1% of the 7431 eligible) persons aged 16 years or older participating in the Andhra Pradesh Eye Disease Study identified from 70 clusters in 3 rural areas and 24 clusters in 1 urban area. Participants aged 40 years or older (n = 3676), 98.7% of the 3724 eligible, who underwent an interview and a detailed dilated ocular eye evaluation by trained professionals were included in this study.

METHODS

The psychometric properties of the VFQ were evaluated among visually impaired persons. The authors examined the relationships of overall visual function score with presenting visual acuity in the better eye, specific eye diseases, and demographic variables.

MAIN OUTCOME MEASURE

Visual function score.

RESULTS

Internal consistency was high for the entire questionnaire (Cronbach's alpha, 0.92). All the items of the visual function scale had an adequate item-total correlation (range, 0.44-0.75) of more than 0.2. After adjusting for demographic variables and ocular disease, persons with visual impairment had significantly lower scores of functional vision. Persons with glaucoma, corneal disease, or retinal disease independent of visual acuity had lower scores compared with persons without these eye diseases. Persons with cataract had significantly lower scores than those without cataract in the model without visual acuity, but did not have significantly lower scores when visual acuity was added to the model.

CONCLUSIONS

The VFQ may be used as a measure of functional vision across a range of visual problems among older adults in Andhra Pradesh. Presenting visual acuity in the better eye was associated with functional vision in this population. Decrease in functional vision was associated with the presence of glaucoma, corneal disease, or retinal disease independent of visual acuity, and with cataract as a function of visual acuity.

Activity of newer fluoroquinolones against gram-positive and gram-negative bacteria isolated from ocular infections: an in vitro comparison

BACKGROUND

To determine the antibacterial activity of newer fluoroquinolones and compare their activity between ciprofloxacin-susceptible and resistant bacterial isolates from patients with keratitis and endophthalmitis.

MATERIALS AND METHODS

The minimum inhibitory concentration (MIC) of ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin and moxifloxacin was determined for 123 bacterial isolates, using E test. Among the 123 isolates, 68 were gram-positive (Staphylococcus spp, Streptococcus spp, Corynebacterium spp, Bacillus spp.) and 55 were gram-negative (Pseudomonas aeruginosa). The bacterial isolates were divided into three groups: susceptible/intermediate/resistant to ciprofloxacin. The MIC values for various fluoroquinolones were compared between the three groups and between gram-positive and gram-negative bacteria.

RESULTS

For gram-positive isolates, median MICs of fourth generation fluoroquinolones were lower than second generation. The median MIC was lowest for gatifloxacin and moxifloxacin (0.094 mg/ml) in ciprofloxacin-susceptible isolates of gram-positive bacteria. For ciprofloxacin-susceptible gram-negative bacteria, the median MIC of ciprofloxacin (0.19 mg/ml) was significantly lower than ofloxacin, levofloxacin, gatifloxacin and moxifloxacin (1.5, 0.5, 0.5 and 2 mg/ml respectively). Ciprofloxacin-resistant isolates of gram-positive bacteria showed higher MIC of levofloxacin, moxifloxacin and gatifloxacin though they remained susceptible to them. None of the fluoroquinolones were effective against ciprofloxacin-resistant gram-negative bacteria. Overall, for gram-positive bacteria, median MICs of levofloxacin, moxifloxacin and gatifloxacin were below ciprofloxacin, the MIC of gatifloxacin and moxifloxacin was equal for gram-positive bacteria.

CONCLUSIONS

Levofloxacin, gatifloxacin and moxifloxacin are statistically more effective against gram-positive bacteria, the latter two being equally effective. Ciprofloxacin remains the most effective fluoroquinolone against gram-negative bacteria.

Comparison of clinical and microbiological profiles in smear-positive and smear-negative cases of suspected microbial keratitis

PURPOSE

To examine the hypothesis that initial smear examination results have a significant bearing on the management and outcome of suspected microbial keratitis.

MATERIALS AND METHODS

One hundred and seventy consecutive patients with suspected microbial keratitis were included in a prospective nonrandomized comparative study and their detailed clinical and microbiological data (smears and cultures of corneal scrapings) were captured on a predesigned corneal ulcer database. Patients were divided into two groups: Group 1 included 68 patients with corneal scrapings negative in smears while Group 2 included 102 patients with corneal scrapings positive in smears. The two groups were compared for their clinico-microbiological profile, management and clinical outcome. The outcome was noted at three months. Fisher's exact test was applied for statistical analysis.

RESULTS

Cultures were sterile in 57.3% of patients in Group 1 compared to 17.6% in Group 2. Scrapings that grew S. pneumoniae, gram-negative organisms, fungi and Acanthamoeba were more often positive in smears (18.6%, 11.8%, 19.6% and 2.9% respectively). While data on duration of prior treatment was not available, prior medication made no significant difference to smear results. More (79.3%) patients of Group 1 had small infiltrate size (

CONCLUSIONS

Initial smear examination helps in instituting specific therapy thereby improving the outcome in cases of microbial keratitis. Positive smears indicate greater severity of disease and prior medication may not be a significant cause of smear negativity.

Impact of impaired vision and eye disease on quality of life in Andhra Pradesh

PURPOSE

To determine the impact of visual impairment and eye diseases on quality of life (QOL) in an older population of Andhra Pradesh in southern India.

METHODS

The World Health Organization (WHO) QOL (WHOQOL) instrument was adapted as a health-related quality of life (HRQOL) instrument for administration to adults participating in the Andhra Pradesh Eye Disease Study. Participants aged 40 years and older (n = 3702), 99.4% of the 3723 eligible, who underwent interview and detailed dilated ocular eye evaluation by trained professionals were included in this study. Psychometric properties of the HRQOL instrument were evaluated among visually impaired people. Relationships among overall QOL scores and presenting visual acuity in the better eye, specific eye diseases, and demographic variables were examined.

RESULTS

Internal consistency was high for the entire questionnaire (alpha = 0.94). Each item of the QOL scale had an adequate item-total correlation (range, 0.25-0.77) greater than 0.2. After adjusting for demographic variables and ocular disease, Subjects with blindness had significantly lower QOL scores. Subjects with glaucoma or corneal disease independent of visual acuity had lower scores than subjects without those eye diseases. Subjects with cataract or retinal disease had significantly lower scores than those without cataract or retinal disease in the model without visual acuity but not when visual acuity was added to the model.

CONCLUSIONS

Decreased QOL was associated with the presence of glaucoma or corneal disease independent of visual acuity and with cataract or retinal disease as a function of visual acuity. Visual impairment from uncorrected refractive errors was not associated with decreased QOL.

Microsporidial keratitis in India: 16S rRNA gene-based PCR assay for diagnosis and species identification of microsporidia in clinical samples

PURPOSE

To evaluate 16S rRNA-based polymerase chain reactions for the detection and species identification of the microsporidia that cause keratitis.

METHODS

Of the 5892 cases of microbial keratitis seen between September 2002 and December 2005, 31 (0.5%) microscopically diagnosed cases of microsporidial keratitis were included in the test group; 103 patients with nonmicrosporidial keratitis constituted the control group. A 16S rRNA-based pan-microsporidian PCR was chosen for the detection of microsporidian DNA. Species level identification was made using species-specific primer sets of Encephalitozoon spp (E. cuniculi, E. hellem, and E. intestinalis). Sequencing and BLAST analysis of amplicons obtained with pan-microsporidian primers were performed for validation.

RESULTS

The corneal scrapings from 26 of 31 cases in the test group and 2 of 103 cases in the control group showed a 250- to 280-bp amplicon in PCR by pan-microsporidian primers (sensitivity of 83% and specificity of 98%). The amplicons of 13 of 26 test group samples were identified by species-specific PCR: E. cuniculi, n = 7 (549 bp); E. hellem; n = 3 (549 bp); E. intestinalis; n = 1 (520 bp). The two cases in the control group were identified to be E. cuniculi. The remaining 15 cases (test group) were confirmed to be Vittaforma corneae by sequencing and BLAST analysis. All species were confirmed by sequencing and database homology comparison.

CONCLUSIONS

This study is the first to validate PCR-based assays for detection of microsporidial DNA in corneal scrapings. Pan microsporidian PCR can be a useful adjunct with smear examination in the diagnosis of microsporidial keratitis.

Analysis of CFH, TLR4, and APOE polymorphism in India suggests the Tyr402His variant of CFH to be a global marker for age-related macular degeneration

PURPOSE

To screen polymorphisms in complement factor-H (CFH), toll-like receptor 4 (TLR4), and APOE genes as potential risk factors for age-related macular degeneration (AMD) in Indian patients.

METHODS

One hundred patients with AMD and 120 normal control subjects were screened for the polymorphisms by restriction digestion and resequencing. Five intragenic SNPs in CFH were screened to generate haplotype data in cases and controls. The data were analyzed in conjunction with data from other populations based on genotype and haplotype frequencies, and odds ratios were computed to estimate the risk of AMD in the different genotypes.

RESULTS

Significant association was noted with the CFH variant (Tyr402His) among AMD cases (P = 1.19 x 10(-7)). Individuals homozygous for the mutant genotype CC had a significantly higher risk (P < 0.0001) of AMD (OR = 11.52; 95% CI 5.05-26.28) than those carrying a single copy of the C allele (OR = 1.51; 95% CI 0.82-2.80), after adjusting for age, gender, and diabetes. Linkage disequilibrium and haplotype analysis at the CFH locus indicated the C-G-T-C-A-G to be a risk haplotype (P = 0.0003). No significant differences were observed in the genotype frequencies of APOE polymorphisms among patients and control subjects (P = 0.76). The carriers of epsilon4 allele had a reduced risk (P = 0.03) of AMD (OR = 0.42, 95% CI 0.19-0.91). TLR4 did not exhibit any association with AMD.

CONCLUSIONS

The CFH polymorphism Tyr402His appears indicative of AMD pathogenesis. Diabetes, age, and gender in the presence of the homozygous "CC" genotype in CFH carry an increased risk of AMD. Hence this polymorphism could be used as a potential marker for predictive testing across continents.

Pilot study on in vivo evaluation of retinal vascular maturity in newborn infants in the context of retinopathy of prematurity

PURPOSE

To study the extent of retinal vascularization at birth.

DESIGN

Prospective masked observational case series.

METHODS

One hundred ten neonates, at different weeks of gestation and birth weights (BWs), had dilated fundus evaluation for zone of retinal vascularization by a masked observer. Maternal and neonatal factors were ascertained by a masked pediatrician.

RESULTS

Irrespective of risk factors, eight of nine babies who were born at <30 weeks of gestation and at <1500 g BW had immature retina. Those babies who were born at >34 weeks of gestational age and at >1700 g BW had mature retina. Babies who were born between 31 to 34 weeks of gestation and at 1501 to 1700 g BW had variable extent of retinal vascularization at birth. Vascularization was affected by maternal anemia and the need for oxygen for >48 hours.

CONCLUSION

There exists considerable variability in the extent of retinal vascularization in infants who are born between 31 to 34 weeks of gestation. Modifiable maternal and fetal factors could influence extent of this vascularization birth.

Surgical outcome of primary developmental glaucoma: a single surgeon's long-term experience from a tertiary eye care centre in India

PURPOSE

To determine the surgical outcome after initial surgery in children with primary developmental glaucoma (PDG).

METHODS

Six hundred and twenty-four eyes of 360 consecutive patients who underwent primary combined trabeculotomy-trabeculectomy (CTT) for PDG from January 1990 to June 2004 were studied. The main outcome measures were pre- and postoperative intraocular pressures (IOPs), corneal clarity, visual acuities, refractive errors, success rate, time of surgical failure, complications, and factors associated with poor outcome.

RESULTS

IOP reduced from 28.1+/-7.5 to 14.9+/-5.9 mmHg (P<0.0001). Probability of success (IOP<21 mmHg) was 85.2, 80.4, 77.2, 72.6, 66.2, and 57.5% at first, second, third, fourth, fifth, and sixth years, respectively (Kaplan-Meier analysis). The mean follow-up period was 20.3+/-25.6 months (median, 6 months). Preoperatively, 243 eyes (67.5%) had significant corneal oedema. Postoperatively, normal corneal transparency was achieved in 162 eyes (46.0%). Data on Snellen visual acuity were available in 100 patients (27.8%). At the final follow-up visit, 42 patients (42.0%) had normal visual acuity (>or=20/60). Myopia (mean spherical equivalent, 6.1 D) was the most common (75.0%) refractive error. In multivariate analyses, failure increased by three-fold in the presence of preoperative IOP>35 mmHg (hazards ratio (HR)=3.12; 95% confidence interval (CI), 1.4-6.7) and two-fold in cases with a history of prior glaucoma surgery (HR=2.57; 95% CI, 1.1-6.0). There were no major intraoperative complications, bleb-related infection, or endophthalmitis.

CONCLUSIONS

This series shows that prolonged IOP control can be achieved in patients with PDG and 42% of the patients gained normal visual acuity.

Clinical outcome of autologous cultivated limbal epithelium transplantation

PURPOSE

To report the clinical outcome of autologous cultivated limbal epithelial transplantation.

METHODS

Eighty-six patients' records and their clinical photographs were reviewed for demographics, primary etiology, type of limbal transplantation, ocular surface stability, visual acuity, final outcome and possible factors affecting outcome and complications.

RESULTS

Eighty-eight eyes of 86 patients with limbal stem cell deficiency (LSCD) underwent autologous cultivated limbal epithelium transplantation between March 2001 and May 2003, with a mean follow-up of 18.3 months. The etiology of LSCD was alkali burns in 64% patients. Sixty-one eyes had total LSCD. Thirty-two of the 88 eyes had undergone amniotic membrane transplantation and 10 eyes had previously undergone limbal transplantation with unfavorable outcome. Nineteen eyes underwent penetrating keratoplasty, of which 11 grafts survived at the final follow-up. Finally, 57 eyes (73.1%, 95% CI: 63.3-82.9) had a successful outcome with a stable ocular surface without conjunctivalization, 21 eyes (26.9%, 95%CI: 17.1-36.7) were considered failures and 10 patients were lost to follow-up.

CONCLUSION

LSCD can be successfully treated by autologous cultivated limbal epithelium transplantation in majority of the cases.

Non-verbal communication in children with visual impairment

The aim of this study was to determine: (a) whether children with visual and additional impairments show any non-verbal behaviours, and if so what were the common behaviours; (b) whether two rehabilitation professionals interpreted the non-verbal behaviours similarly; and (c) whether a speech pathologist and a rehabilitation professional interpreted the behaviours similarly. Twelve children, aged from two to eight years, with visual and additional impairments, were videotaped during their play sessions to observe their non-verbal behaviour. A rehabilitation professional observed the tapes and identified and interpreted 131 non-verbal behaviours. The study found that the children showed 33 common behaviours. There was 98.4 per cent agreement between the two rehabilitation professionals, and there was 88.5 per cent agreement between the first rehabilitation professional and the speech therapist. The authors go on to suggest strategies for developing the non-verbal behaviours of children with visual and additional impairments.

Risk Factors for Age-Related Macular Degeneration: Findings from the Andhra Pradesh Eye Disease Study in South India

PURPOSE

To assess prevalence, potential risk factors, and population attributable risk percentage (PAR%) for age-related macular degeneration (AMD) in the Indian state of Andhra Pradesh.

METHODS

A population-based study, using a stratified, random, cluster, systematic sampling strategy, was conducted in the state of Andhra Pradesh in India from 1996 to 2000. Participants from 94 clusters in one urban and three rural areas representative of the population of Andhra Pradesh underwent a detailed interview and a detailed dilated ocular evaluation by trained professionals. In this report, the authors present the prevalence estimates of AMD and examine the association of AMD with potential risk factors in persons aged 40 to 102 years (n = 3723). AMD was defined according to the international classification and grading system. Standard bivariate and multivariate analyses were performed to identify the potential risk factors for AMD. PAR% was calculated by Levin's formula.

RESULTS

AMD was present in 71 subjects--an age-gender-area-adjusted prevalence of 1.82% (95% confidence interval [CI], 1.39%-2.25%). Risk factors that were significant in bivariate analyses were considered for multivariate logistic regression analysis. Multivariate analysis showed that the adjusted prevalence of AMD was significantly higher in those 60 years of age or older (odds ratio [OR], 3.55; 95% CI, 1.61-7.82) and history of prior cigar smoking (OR, 3.29; 95%CI, 1.42-7.57). Presence of cortical cataract and prior cataract surgery were significantly associated with increased prevalence of AMD (adjusted OR, 2.87; 95% CI, 1.57-5.26 and 3.79; 95% CI, 2.1-6.78), respectively. The prevalence of AMD was significantly lower in light alcohol drinkers (adjusted OR, 0.38; 95% CI, 0.19-0.76) compared with nondrinkers. The PAR% for hypertension and heavy cigar smoking was 10% and 14%, respectively, in this population.

CONCLUSIONS

The prevalence of AMD in this south Indian population is similar to those reported in other developed countries. Abstinence from smoking may reduce the risk of AMD in this population.

Comparison of mean macular thickness using optical coherence tomography and visual acuity in diabetic retinopathy

BACKGROUND

The purpose of the present study was to quantitatively assess the mean macular thickness in diabetic patients using optical coherence tomography and its correlation with visual acuity.

METHODS

A prospective case series study was undertaken of consecutive diabetic patients referred to a tertiary eye care centre for an eye check up from January 2003 to June 2003. One hundred and five eyes from 55 patients with varying degree of diabetes underwent optical coherence tomography examination. The study patients were divided into four groups: group I, non-proliferative diabetic retinopathy (NPDR); group II, NPDR with clinically significant macular oedema (CSME); group III, proliferative diabetic retinopathy (PDR); and group IV, PDR with CSME.

RESULTS

The mean macular thickness of the entire group was 256.0 +/- 129.7 microm. A positive correlation (r = 0.424, P < 0.0001) was evident between mean macular thickness and visual acuity.

CONCLUSION

Optical coherence tomography is a useful tool for objectively monitoring macular thickness in patients with diabetic retinopathy. Mean macular thickness correlates with visual acuity.

Outcome of cataract extraction and posterior chamber intraocular lens implantation following glaucoma filtration surgery

PURPOSE

To evaluate the outcome of cataract extraction (CE) after glaucoma filtering surgery (GFS).

METHODS

A total of 77 eyes (77 patients) who underwent CE with posterior chamber intraocular lens (PCIOL) implantation following GFS by a single surgeon were reviewed. Main outcome measures were preoperative and postoperative intraocular pressures (IOPs), visual acuities, medications, astigmatism, bleb survival, time of surgical failure, complications, and success rate.

RESULTS

Mean time interval between GFS and CE was 46.8+/-50.9 months (range, 2-348 months). The mean preoperative IOP was 13.9+/-4.7 mmHg (range 3-27 mmHg) and mean postoperative IOP at 3 weeks was 13.6+/-5.5 mmHg (range, 6-44 mmHg). The mean follow-up was 19.5+/-20.1 months (range, 1.4-73 months; median 10.6 months). Complete success was achieved in 59 eyes (76.7%). The cumulative probability of complete success was 91.3+/-3.7, 82.0+/-5.6 and 78.1+/-6.5% at the end of 6 months, 1, and 2 years, respectively. Visual acuity before CE was < or =20/50 in all eyes (100%). Visual acuity at last visit was > or =20/40 in 33 eyes (42.8 %), 20/50-20/80 in 30 eyes (39.0%), < or =20/100 in 14 eyes (18.2%). Risk factors identified for qualified success included age at CE>60 years, interval of < or =5 months between GFS and CE, use of preoperative glaucoma medications, and postoperative IOP >19 mmHg within 2 weeks.

CONCLUSIONS

IOP and bleb function was maintained after CE with PCIOL implantation following successful GFS with good visual recovery.

Combined trabeculotomy and trabeculectomy in advanced primary developmental glaucoma with corneal diameter of 14 mm or more

PURPOSE

To report the safety and efficacy of combined trabeculotomy and trabeculectomy (CTT) in advanced primary developmental glaucoma with corneal diameter 14 mm or more.

PATIENTS AND METHODS

A total of 74 (121 eyes) consecutive patients aged 3 days-100 months (median, 10 months) with advanced developmental glaucoma were included. Primary CTT was performed by a single surgeon at a tertiary eye care centre in India over a 13-year period. The main outcome measures were changes in and final levels of intraocular pressure (IOP), corneal clarity, visual acuity, and refractive status.

RESULTS

Mean preoperative IOP was 29.4+/-7.6 mmHg (range, 10-56 mmHg) and mean postoperative IOP was 15.5+/-6.6 mmHg (range, 6-38 mmHg) (P<0.0001) with percentage reduction of 44.5+/-27.1. Kaplan-Meier survival analysis revealed 3-, 6-, 9-, 12-, 24-, 48-, and 72-month success rates of 86.5, 80.5, 78.1, 75.5, 71.1, and 60.5%, respectively. Majority (80.5%) of the patients were myopes with mean spherical equivalent of 5.8+/-4.5D (range, 0.75-22.0D). Using various age-appropriate testing procedures, at the final follow-up visit, 14 patients (41.2%) had age-appropriate normal visual acuity and 20 patients (58.8%) had subnormal visual acuity. Best-spectacle-corrected visual acuity of > or =20/60 was achieved in seven patients (26.9%). There were no sight-threatening intraoperative and postoperative complications.

CONCLUSION

CTT is safe and effective in patients with advanced primary developmental glaucoma. It offers good IOP control with a low complication rate, with about one-third of patients achieving a visual acuity of 20/60 or better.

Retinal detachment in south India-presentation and treatment outcomes

BACKGROUND

Although the presentation and treatment outcomes of retinal detachments in wealthy countries are well known, much less is known about retinal detachment in the developing world. This study reports the presentation and outcomes of 433 rhegmatogenous retinal detachments in South India.

METHODS

Retrospective analysis was undertaken of all operated cases of retinal detachment in a tertiary care centre, from 1 January 2000 to 31 December 2000.

RESULTS

Retinal detachments were treated in 433 eyes of 417 patients; 67 (16.1%) patients were children below 16 years and 60 (14.4%) patients were blind (visual acuity <6/60). The duration of symptoms was over 1 month in 192 (46.6%) eyes and, in 376 (86.8%), the macula was detached at presentation. Referral diagnosis was incorrect in 69 (22.4%) eyes. Cataract surgery was the predisposing factor in 152 (35.1%) eyes. Primary surgery included pars plana vitrectomy procedures in 235 eyes (53.9%) and scleral buckling in 197 (45.8%). The retina was re-attached with one operation in 281 eyes (71%) and with one or more operations in 333 (87%). Visual acuity of 6/60 or better was achieved in 260 (67.7%) eyes.

CONCLUSIONS

The profile of retinal detachments in a tertiary eye care centre in south India includes many paediatric cases, late presentations and macula-off detachments, commonly related to cataract surgery. Despite complex pathology, two thirds of eyes regain useful vision after one or more surgical interventions.

Outcome of pterygium surgery: analysis over 14 years

AIM

To report the outcome of pterygium surgery performed at a tertiary eye care centre in South India.

METHODS

Retrospective analysis of medical records of 920 patients (989 eyes) with primary and recurrent pterygia operated between January 1988 and December 2001. The demographic variables, surgical technique (bare sclera, primary closure, amniotic membrane transplantation (AMT), conjunctival autograft (CAG), conjunctival-limbal autograft (CLAG), or surgical adjuvants), recurrences and postoperative complications were analysed.

RESULTS

A total of 496 (53.9%) were male and 69 (7.5%) had bilateral pterygia. Bare sclera technique was performed in 267 (27.0%) eyes, primary conjunctival closure in 32 (3.2%), AMG in 123 (12.4%), CAG in 429 (43.4%), and CLAG in 70 (7.1%). Adjuvant mitomycin C was used in 44 (4.4%) cases. The mean duration of follow-up was 8.9+/-17.0 and 5.9+/-8.8 months for unilateral primary and recurrent pterygia, respectively. The overall recurrence rate was 178 (18.0%). Following primary and recurrent unilateral pterygium excision respectively, recurrences were noted in 46 (19.4%) and 1 (33.3%) eyes after bare sclera technique, five (16.7%) and 0 after primary closure, 28 (26.7%) and 0 with AMG, 42 (12.2%) and five (31.3%) with CAG, and nine (17.3%) and two (40%) with CLAG. Recurrences were significantly more in males with primary (23.3 vs 10.7%, P<0.0001) and recurrent (26.7 vs 0%, P=0.034) pterygia, and in those below 40 years (25.2 vs 14.8%, P=0.003).

CONCLUSION

CAG appears to be an effective modality for primary and recurrent pterygia. Males and patients below 40 years face greater risk of recurrence. Bare sclera technique has an unacceptably high recurrence. Prospective studies comparing CAG, CLAG, and AMG for primary and recurrent pterygia are needed.

Pellucid marginal corneal degeneration*1

OBJECTIVE

To report the clinical features and outcome of patients with pellucid marginal corneal degeneration (PMCD).

DESIGN

Retrospective noncomparative case series.

METHODS

Retrospective chart review of 116 eyes of 58 patients with PMCD seen between 1990 and 2002 at the Cornea Service at L.V. Prasad Eye Institute, Hyderabad, India. The diagnosis of PMCD was based on the presence of corneal thinning with ectasia of the normal cornea above or below the area of thinning with no evidence of scarring, vascularization, or lipid deposition and typical topographic features whenever topography was performed. A detailed history including the age of presentation, onset of symptoms, systemic diseases, atopy, and relevant family history was reviewed. The visual acuity (VA) at presentation; the location, extent, and degree of thinning; presence of concurrent keratoconus and keratoglobus; and complications, if any, were noted. The mode of visual rehabilitation; surgical procedure, if any; and the final VA achieved were analyzed.

MAIN OUTCOME MEASURES

Clinical features, associations, complications, and outcome of treatment.

RESULTS

There were 45 males (77.6%) and 13 females (22.4%). All cases were bilateral. In one eye, no clinical features of PMCD were seen, but the diagnosis was made based on topographic features of typical PMCD. The age of the patients ranged from 8 to 66 years, with a mean of 34.0+/-14.8. One patient (1.7%) had associated vernal keratoconjunctivitis (VKC), 1 (1.7%) had Marfan's syndrome, and 1 (1.7%) had ocular hypertension. The degree of astigmatism was <5.0 diopters (D) in 19 eyes (19.2%), 5 to 10 D in 36 (36.4%), 10 to 15 D in 23 (23.2%), 15 to 20 D in 15 (15.2%), and >20 D in 6 (6.1%). Typical inferior PMCD was seen in 99 eyes (85.3%), and superior PMCD was seen in 17 (14.7%). The thinning was commonly seen between the 5-o'clock and 7-o'clock positions. In 12 eyes (10.3%), PMCD was associated with keratoconus, and in 15 eyes (12.9%), keratoglobus was associated. Seven eyes (6.0%) had hydrops. Visual acuity improved in 52 eyes (55.3%) with correction, in 40 eyes (42.6%) it remained the same as that of the initial presentation, and in 2 eyes (2.1%) it worsened relative to the initial presentation. Forty-one eyes (35.3%) received spectacles, and 31 eyes (26.7%) were fitted with rigid gas-permeable contact lenses. Five eyes (4.3%) underwent surgery. Lamellar keratoplasty was performed in 3 eyes, and a crescentic lamellar graft was done in 2 eyes. Visual acuity improved in 4 eyes after surgery with a follow-up of 2 to 37 months. The final astigmatism in the operated eyes at the last follow-up ranged from 4 to 11 D.

CONCLUSIONS

Pellucid marginal corneal degeneration was seen predominantly in males in this series, and was not strongly associated with VKC. Keratoconus was seen in approximately 10% of the eyes, and keratoglobus in approximately 13%. Superior PMCD was seen in approximately 15% of the eyes. In our study, patients presented with severe astigmatism, and hydrops was a common complication. The majority of patients were treated with spectacles or contact lens. Surgery for PMCD-lamellar keratoplasty and crescentic lamellar keratoplasty, if indicated-usually results in significant residual astigmatism.

Awareness of eye donation in the rural population of India

PURPOSE

To determine the "awareness of eye donation" and "willingness to pledge eyes for donation" in the rural population of Andhra Pradesh, southern India.

METHODS

A total of 7,775 subjects of all ages, representative of the rural population of Andhra Pradesh, participated in the Andhra Pradesh Eye Disease Study (APEDS). Subjects older than 15 years were interviewed regarding awareness of eye donation and willingness to pledge eyes for donation.

RESULTS

Age-gender adjusted prevalence of awareness of eye donation in this population was 30.7% (95% CI: 29.5-31.9) but only 0.1% (age-gender adjusted prevalence) (95% CI: 0.05-0.25) had pledged eyes. On multivariate analysis the awareness of eye donation was significantly less in those subjects > or = 70 years old (OR 0.7; 95% CI: 0.6-0.8), illiterates (OR 0.2; 95% CI: 0.1-0.2), females (OR 0.8; 95% CI: 0.7-0.9), lower socioeconomic status group (OR 0.4; 95% CI: 0.4-0.5) and Christians (OR 0.2; 95% CI: 0.1-0.6). Media comprised the major source of information about eye donation. Of those aware of eye donation, 32.9% were willing to pledge eyes, and 50.6% needed more information to decide whether or not to pledge their eyes.

CONCLUSIONS

There needs to be more transfer of knowledge if more eyes are to be pledged. One-third of those aware of eye donation have not pledged their eyes, and an additional 50.6% needed more information to decide. This means only about one-fifth of those aware of eye donations have pledged their eyes.

Long-term surgical and visual outcomes in Indian children with developmental glaucoma operated on within 6 months of birth

PURPOSE

To determine the long-term surgical and visual outcomes in Indian children with developmental glaucoma operated within 6 months of birth.

DESIGN

Retrospective consecutive, noncomparative case series.

PARTICIPANTS

All children with developmental glaucoma who underwent surgery within 6 months of birth over a 12-year period were included.

METHODS

Two hundred ninety-nine eyes of 157 consecutive patients who underwent primary combined trabeculotomy-trabeculectomy for developmental glaucoma from January 1990 through December 2001 by a single surgeon were studied. However, for the purpose of statistical analysis, only 1 randomly chosen eye of patients with a bilateral affliction (142, 90.4%) was considered.

MAIN OUTCOME MEASURES

The main outcome measures were preoperative and postoperative intraocular pressures (IOPs), corneal clarity and diameters, visual acuities, refractive errors, success rate, time of surgical failure, and complications.

RESULTS

The series consisted of 299 primary combined trabeculotomy-trabeculectomy surgeries during 157 anesthesias. The intraocular pressure was reduced from 26.6+/-6.2 mmHg to 14.4+/-4.9 mmHg, with a mean percentage reduction of 41.1+/-28.8 (P<0.0001). The probability of success (IOP<21 mmHg) was 94.4%, 92.1%, 86.7%, 79.4%, 72.9%, and 63.1% at first, second, third, fourth, fifth, and sixth year, respectively (Kaplan-Meier analysis). The mean follow-up period was 26.5+/-25.1 months. Preoperatively, 133 eyes (84.7%) had significant corneal edema. Postoperatively, normal corneal clarity was achieved in 83 of 133 eyes (62.4%) with corneal edema. There were no major intraoperative complications. Postoperatively, 17 eyes (10.8%) had a shallow anterior chamber develop; 3 of these eyes (17.6%) required surgical reformation. There was no incidence of endophthalmitis or any other sight-threatening complication. Data on visual acuity were available in 49 patients (31.2%). At the final follow-up visit, 20 patients (40.8%) had normal visual acuity (best-corrected visual acuity of >/=20/60 in the better eye).

CONCLUSIONS

Primary combined trabeculotomy-trabeculectomy is safe and effective for developmental glaucoma when performed within 6 months of birth. It leads to excellent IOP control and moderate visual outcome.

Safety and efficacy evaluation of a new electrode (the LVP electrode) part I. Pattern ERG pilot study

We have designed a less expensive, non-corneal ERG electrode. Named as the LVP electrode, this new disposable electrode was found safe and reliable for pattern ERG recordings.

Safety and efficacy evaluation of a new ERG electrode (the LVP electrode) part II. Flash ERG pilot study

A new disposable, non-contact electrode (LVP electrode) was evaluated for use in recording flash ERG. A comparison of DTL and LVP electrodes showed reproducible waveforms for all components analysed. There was a good correlation obtained between the DTL and LVP electrodes. The LVP electrode is safe, less expensive and has less movement of the fiber due to its rigidity.

Outcome of surgery on infants younger than 1 month with congenital glaucoma

PURPOSE

To determine the visual outcomes and surgical and anesthetic complication rates of patients with newborn glaucoma operated within 1 month of age.

DESIGN

Retrospective, consecutive, noncomparative case series.

PARTICIPANTS

All children with newborn glaucoma who underwent surgery between January 1990 and December 2000 were included.

METHODS

The medical records of 25 consecutive patients (47 eyes) who underwent primary combined trabeculotomy and trabeculectomy either bilaterally in a single session or unilaterally were reviewed retrospectively. Outcomes were evaluated using Kaplan-Meier survival analysis.

MAIN OUTCOME MEASURES

Clinical outcome assessment included corneal clarity, intraocular pressure (IOP), bleb characteristics, visual acuity, refractive errors, and identification of surgical and anesthetic complications.

RESULTS

The mean follow-up was 3.1+/-1.8 years (range, 9.5 months-7.4 years). The mean preoperative IOP was 26.9+/-5.2 mmHg (range, 14-42 mmHg). At the final follow-up visit, the mean IOP was 14.5+/-3.8 mmHg (range, 8-28 mmHg). The percentage reduction in IOP was 43.3+/-21.5 (P<0.0001). Twelve-, 24-, and 36-month survival rates for complete success for IOP control were 89.4%, 83.6%, and 71.7%, respectively, which were maintained for 7 years of follow-up. After surgery, complete clearance of corneal edema was achieved in 66% of the eyes. Data on visual acuity was available for 19 patients. Final best spectacle-corrected visual acuity was 20/40 or better in the better eye in 5 patients (26.3%), 7 patients (36.8%) obtained 20/60 or better in the better eye, 8 patients (42.1%) achieved final visual acuity of less than 20/60 to 20/200 in the better eye (low vision), and four patients obtained less than 20/400 visual acuity in the better eye (blind) according to World Health Organization criteria. However, there was no eye with absent perception of light in the better eye. Myopia (mean spherical equivalent, 4.6+/-3.2 diopters) was the most common refractive error, present in approximately half of the eyes (n = 23; 53.8%). There were no significant intraoperative or postoperative complications in any patient. Anesthesia-related complications developed in 2 patients; however, they were resuscitated successfully.

CONCLUSIONS

Primary combined trabeculotomy-trabeculectomy offers a viable surgical option in infants that have cloudy corneas at birth as a result of congenital glaucoma. It is associated with a favorable visual outcome and a low rate of anesthetic complications in an Indian population.

The development of the LV Prasad-Functional Vision Questionnaire: a measure of functional vision performance of visually impaired children

PURPOSE

To develop a reliable and valid questionnaire (the LV Prasad-Functional Vision Questionnaire, LVP-FVQ) to assess self-reported functional vision problems of visually impaired school children.

METHODS

The LVP-FVQ consisting of 19 items was administered verbally to 78 visually impaired Indian school children aged 8 to 18 years. Responses for each item were rated on a 5-point scale. A Rasch analysis of the ordinal difficulty ratings was used to estimate interval measures of perceived visual ability for functional vision performance.

RESULTS

Content validity of the LVP-FVQ was shown by the good separation index (3.75) and high reliability scores (0.93) for the item parameters. Construct validity was shown with good model fit statistics. Criterion validity of the LVP-FVQ was shown by good discrimination among subjects who answered "seeing much worse" versus "as well as"; "seeing much worse" versus "as well as/a little worse" and "seeing much worse" versus "a little worse," compared with their normal-sighted friends. The task that required the least visual ability was "walking alone in the corridor at school"; the task that required the most was "reading a textbook at arm's length." The estimated person measures of visual ability were linear with logarithm of the minimum angle of resolution (logMAR) acuity and the binocular high contrast distance visual acuity accounted for 32.6% of the variability in the person measure.

CONCLUSIONS

The LVP-FVQ is a reliable, valid, and simple questionnaire that can be used to measure functional vision in visually impaired children in developing countries such as India.

Clinical experience with N-butyl cyanoacrylate tissue adhesive in fungal keratitis

PURPOSE

To evaluate the role of tissue adhesive in the management of corneal thinning or perforation associated with active fungal keratitis.

DESIGN

Retrospective noncomparative interventional case series.

METHODS

Seventy-three eyes of 73 patients with microbiologically proven keratomycosis associated with thinning or perforation participated in the study. N-Butyl cyanoacrylate tissue adhesive (medical grade) and bandage contact lens were applied in addition to topical and systemic antifungal therapy. Our outcome measures included resolution of the infiltrate and preservation of the structural integrity of the globe.

RESULTS

Outcome data were available for 66 eyes. The infiltrate resolved with scar formation in 42 (63.6%) eyes. In an additional eight (12.1%) eyes, tissue adhesive maintained the structural integrity of the globe while the patients awaited penetrating keratoplasty. Sixteen (24.2%) eyes showed progressive worsening or persistence of the infiltrate after application of tissue adhesive. Twenty-five (37.8%) eyes required multiple applications of tissue adhesive. The outcome was better in cases where the infiltrate measured less than 30 mm2 at the time of presentation and application of tissue adhesive (P < 0.01).

CONCLUSION

In view of the poor outcome of penetrating keratoplasty in active fungal keratitis, N-butyl cyanoacrylate tissue adhesive is a useful modality for the management of progressive thinning or perforation associated with active fungal keratitis. However, close observation is mandatory to assess the progression of disease.

Humphrey visual field and frequency doubling perimetry in the diagnosis of early glaucoma

PURPOSE

To compare Humphrey Visual Field Analyzer (HVF) and Frequency Doubling Perimetry (FDP) testing in the diagnosis of early glaucoma.

METHODS

We performed HVF (24-2 standard full threshold) and FDP (N-30) evaluations in 34 consecutive patients with early primary glaucoma and 96 normal subjects. Early glaucoma was defined on the basis of disc changes of glaucoma; the mean deviation on white-on-white perimetry had to be no worse than 6 decibels. Glaucomatous optic neuropathy was defined as a combination of cup-disc asymmetry of more than 0.2, notching, excavation, thinning or pallor of superior or inferior neuroretinal rims, retinal nerve fibre layer defects of the wedge or diffuse type and neuroretinal rim haemorrhage. Both the glaucoma patients and normal subjects had vision better than 6/9 with correction. They had no media opacities other than early nuclear sclerosis and no fundus pathology. Further, normal subjects were free of systemic diseases known to affect the retina or optic nerve. The sensitivity and specificity of HVF and FDP were calculated.

RESULTS

There were 44 eligible eyes among the 34 subjects. The glaucomatous disc findings included notch (n=8), pallor (n=21), thinning (n=23) and haemorrhage (n=1) of the neuroretinal rim. The sensitivity and the specificity of the HVF were 52.3% and 57.3% respectively. The sensitivity and the specificity of FDP were 65.9% and 61.5% respectively.

CONCLUSION

The difference between FDP and HVF in the diagnosis of early glaucoma is not marked.

Trabeculectomy with or without mitomycin-C for paediatric glaucoma in aphakia and pseudophakia following congenital cataract surgery

PURPOSE

To evaluate the safety and efficacy of trabeculectomy with or without mitomycin-C (MMC) in the management of glaucoma in aphakia and pseudophakia following congenital cataract surgery.

PATIENTS AND METHODS

All patients of glaucoma with aphakia or pseudophakia who underwent trabeculectomy with or without MMC from January 1989 to April 2000 were included. The medical records of 19 consecutive patients (23 eyes) were reviewed. Data collected from a retrospective chart review were analysed. Outcome measures were evaluated using Kaplan-Meier survival analysis. Pre- and postoperative intraocular pressures (IOPs), visual acuities, success rate, bleb characteristics, surgical failure and complications were the main outcome measures. Successful IOP control was defined as an IOP between 6 and 21 mmHg, without antiglaucoma medications, without further antiglaucoma surgery and without any sight-threatening complication.

RESULTS

The mean age of patients was 8.8+/-5.5 years at the time of trabeculectomy with MMC compared to 11.0+/-12.4 years for trabeculectomy without MMC. Eight patients underwent trabeculectomy with MMC and 11 patients underwent trabeculectomy without MMC. There was no statistically significant difference between the two groups in terms of visual acuity, IOP, antiglaucoma medications, age at cataract surgery and at trabeculectomy. The IOP reduced from a preoperative level of 34.2+/-8.9 mmHg (range: 20-52) to a postoperative level of 18.4+/-12.2 mmHg (range: 2-60) with a mean follow-up of 24.2+/-17.9 months. The mean reduction in IOP in the MMC group was 15.5+/-17.3 and 16.3+/-13.8 mmHg in the other group (P = 0.967). Overall, complete success was achieved in 36.8%, qualified success in 21.1% and surgical failure in 42.1% of patients with a mean follow-up of 24.2+/-17.9 months. There was no difference in the success between the two groups at the last follow-up. One patient developed bleb-related endophthalmitis in both eyes following trabeculectomy with MMC.

CONCLUSIONS

The success rate of trabeculectomy in glaucoma following congenital cataract surgery was 36.8% at the end of 3 years. The present study proves a poor success rate of trabeculectomy in a small series of aphakic Asian Indian patients even with the use of MMC.

An ultrasound biomicroscopic study of the anterior segment in Indian eyes with primary angle-closure glaucoma

PURPOSE

To evaluate the presence of plateau iris in eyes with primary angle-closure glaucoma (PACG) after laser peripheral iridotomy by gonioscopy and ultrasound biomicroscopy and to evaluate the pathogenesis of this condition by comparing the UBM parameters of these eyes with those in normal subjects.

PATIENTS AND METHODS

This prospective study was carried out in the Glaucoma clinic of a tertiary eye care center. A detailed clinical examination including applanation tonometry, indentation gonioscopy with a Sussman four-mirror gonioscope, and ultrasound biomicroscopic examination in one randomly selected eye of 55 patients (55 eyes) with PACG who had undergone laser peripheral iridotomy and 22 normal subjects (22 eyes).

RESULTS

Among the PACG eyes, 40% (22/55) had an open angle (angle opening distance > 130 microns) and 60% (33/55) eyes had a narrow angle (angle opening distance <or= 130 microns). A large anteriorly placed ciliary process with a narrow ciliary sulcus was found in 9 of the 22 eyes with open angle (40.9%), and 22 of the 33 eyes with narrow angles (66.66%). Trabecular ciliary process distance was significantly larger in the eyes with open angles compared with those with narrow angles ( = 0.001).

CONCLUSIONS

Plateau iris was common in the clinic population studied. Anteriorly directed ciliary processes were seen both in eyes with plateau iris as well as in eyes with PACG that had deep anterior chambers after iridotomy.

Low vision rehabilitation in patients with age-related macular degeneration at a tertiary eye care centre in southern India

PURPOSE

To evaluate the specific needs and types of low vision devices (LVDs) in patients with age-related macular degeneration (AMD) so as to use the residual vision effectively.

METHODS

One hundred consecutive patients with diagnosis of AMD were evaluated to ascertain the degree of visual disability. Different LVDs were used to suit the specific needs of individual patients. The distribution of LVDs for distance and near and other rehabilitation measures were stratified for vision >or=6/18 and <6/18. Statistical analysis was performed using chi2 test/Fisher's exact test and paired t-test.

RESULTS

The percentage of patients with visual acuity <6/18 reduced from 72.2% (26/36) to 47.2% (17/36) with the use of standard spectacles (P = 0.03). Similarly, the percentage of patients with visual acuity <6/18 reduced from 85.7% (6/7) to 14.3% (1/7) with the use of a telescope (P = 0.029). The optical devices for near tasks included spectacle magnifiers (n = 59), stand magnifiers (n = 19), and hand magnifiers (n = 18). With these LVDs, the near vision improved from 0.13 (decimal notations) to 0.39 (P < 0.001). Eighty-six patients were given at least one of the LVDs and 20% were prescribed more than one near device (bifocals, spectacle magnifiers, hand magnifiers, stand magnifiers). Additionally, patients also needed counselling (n = 89) and training on eccentric viewing (n = 39), coin identification (n = 45), and independent mobility (n = 41).

CONCLUSION

The overall management of a patient with AMD must include counselling, prescription of appropriate LVDs and training to utilize the residual vision to its fullest advantage. This is expected to improve the patient's quality of life.

Mitomycin-C-augmented trabeculectomy for neovascular glaucoma. A preliminary report

PURPOSE

This study aimed to investigate the safety and efficacy of trabeculectomy with intraoperative mitomycin C (MMC) in the management of eyes with neovascular glaucoma (NVG).

METHODS

Fifteen eyes of 14 patients with NVG were included in the study. NVG was secondary to central retinal vein occlusion (3 eyes), hemiretinal vein occlusion (2 eyes), proliferative diabetic retinopathy (8 eyes), branch retinal vein occlusion (1 eye) and idiopathic (1 eye). Preoperative retinal ablation was performed in eyes with evidence of posterior segment ischaemia. Following this, all eyes underwent trabeculectomy with intraoperative MMC (0.4 mg/ml for 3 minutes). Clinical outcome assessment included visual acuity, intraocular pressure (IOP), bleb appearance, identification of complications and antiglaucoma medications required to control IOP.

RESULTS

The mean IOP decreased from 38.6 +/- 12.9 mmHg (range, 15-64 mmHg) to 17.4 +/- 9.33 mmHg (range, 4-34 mmHg) (P = 0.001). Preoperative visual acuity ranged from light perception to 6/9 in the affected eye. Thirteen (86.6%) of 15 eyes improved vision or retained preoperative vision, one (6.7%) eye lost light perception and one (6.7%) eye developed tractional retinal detachment two years after trabeculectomy. Ten (66.7%) of 15 eyes were classified as surgical success with a mean follow-up of 28.6 +/- 26.3 months (range, 2-82 months). None of the patients developed choroidal haemorrhage, hypotony maculopathy, late onset bleb leak or endophthalmitis.

CONCLUSION

Trabeculectomy with intraoperative MMC is a good treatment modality in the management of eyes with NVG.

Planning low vision services in India : a population-based perspective

OBJECTIVE

To assess the prevalence and causes of low vision in a population in southern India for planning low vision services.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

A total of 10,293 persons of all ages from 94 clusters representative of the population of the Indian state of Andhra Pradesh.

METHODS

The participants underwent a detailed eye examination, including measurement of visual acuity with logarithm of the minimum angle of resolution charts, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, and stereoscopic dilated fundus evaluation. Automated threshold visual fields and slit-lamp and fundus photography were done when indicated using predefined criteria.

MAIN OUTCOME MEASURES

Low vision was defined as permanent visual impairment that was not correctable with refractive error correction or surgical intervention. The participants with best-corrected distance visual acuity <6/18 to perception of light or central visual field <10 degrees because of an untreatable cause in both eyes were considered as having low vision.

RESULTS

Low vision was present in 144 participants, an age, gender, and urban-rural distribution adjusted prevalence of 1.05% (95% confidence interval, 0.82%-1.28%). The most frequent causes of low vision included retinal diseases (35.2%), amblyopia (25.7%), optic atrophy (14.3%), glaucoma (11.4%), and corneal diseases (8.6%). Multivariate analysis showed that the prevalence of low vision was significantly higher with increasing age, and there was a trend for higher prevalence with decreasing socioeconomic status. Extrapolating these data to the estimated 1014 million population of India in the year 2000, 10.6 (95% confidence interval, 8.4-12.8) million people would have low vision.

CONCLUSIONS

These data imply that there is a significant burden of low vision in this population, suggesting the need for low vision services.

Comparison of an immortalized human corneal epithelial cell line with Vero cells in the isolation of Herpes simplex virus-1 for the laboratory diagnosis of Herpes simplex keratitis

BACKGROUND

Herpes simplex keratitis (HSK) is a sight threatening ocular infection often requiring a specific and prompt laboratory diagnosis. Isolation of Herpes simplex virus (HSV-1) in culture provides the most reliable and specific method and is considered as the "Gold Standard" in the laboratory diagnosis of HSK in spite of its low sensitivity. Using "cell lines of corneal origin" for virus isolation may be beneficial under such circumstances, since these cells have been shown to be excellent substrates for the growth of HSV-1 isolated from the cornea. We report a comparative study of a novel human corneal epithelial cell line (HCE) and the Vero cell line in the isolation of HSV-1 from corneal scrapings employing a shell vial assay.

METHODS

Corneal scrapings were obtained from 17 patients with a clinical diagnosis of HSK. All the cases were confirmed by virological investigations (PCR and viral antigen detection positive, n = 15, PCR positive, n = 1, Viral antigen positive, n = 1). Scrapings obtained from 10 patients with infectious keratitis of non-viral origin were included as controls. All the scrapings were simultaneously inoculated into shell vials of HCE and Vero cells. Cultures were terminated at 24 h post-infection. Isolation of HSV-1 was confirmed using an indirect immunofluorescence/ immunoperoxidase assay.

RESULTS

Virus could be isolated using both or either of the cell lines in 10/17 (58.82%) patients with HSK. HSV-1 was isolated from 10/17 (58.82%) and 4/17(23.52%) specimens in HCE and Vero cells, respectively (P = 0.036). None of the controls yielded HSV-1. While all the 10 (100%) strains were isolated in HCE, Vero yielded only 4/10 (40%) strains in the shell vial culture (P = 0.014).

CONCLUSIONS

HCE showed a statistically significant difference in the virus isolation rate with respect to Vero cells. HCE may be an excellent alternative cell line for the isolation of HSV-1, especially from corneal scrapings, for the laboratory diagnosis of HSK.

Safety and efficacy of simultaneous bilateral primary combined trabeculotomy-trabeculectomy for developmental glaucoma

PURPOSE

To establish the safety and efficacy of simultaneous bilateral primary combined trabeculotomy-trabeculectomy for developmental glaucoma.

METHODS

We studied 109 consecutive patients who underwent planned simultaneous bilateral primary combined trabeculotomy-trabeculectomy for developmental glaucoma by a single surgeon from January 1990 through December 1999. The main outcome measures were postoperative intraocular pressure (IOP), corneal clarity and diameter, visual acuity, bleb characteristics, time of surgical failure and complications. Postoperative complications including endophthalmitis and anaesthetic morbidity and mortality were also analysed.

RESULTS

The series consisted of 218 primary combined trabeculotomy-trabeculectomy surgeries during 109 anaesthesias. The mean follow-up period was 16.33 +/- 16.22 months. The IOP reduced from 26.4 +/- 5.9 mmHg to 13.5 +/- 4.5 mmHg, with a mean percentage reduction of 46.2 +/- 23.7 (P < 0.0001). The success (IOP < 16 mmHg) probabilities were 90.9%, 88.0% and 69.3% at first, second and third year respectively (Kaplan-Meier analysis). The success probability of 69.3% obtained at third year was maintained till 6 years of follow-up. One hundred and sixty six (76.1%) eyes had significant corneal oedema. Postoperatively, the cornea cleared in 93 (57.8%) eyes. Clinically, well functioning blebs were present in 114 of 171 eyes (66.6%). Postoperatively, 18 (8.3%) eyes developed shallow anterior chamber and 6 (33.3%) of them required surgical reformation. There was no incidence of endophthalmitis or any other sight-threatening complication. Of the anesthetic complications, apnea occurred in 17 (15.6%) patients and all were successfully resuscitated. The most serious post-anaesthetic complication was cardio-pulmonary arrest that occurred 5 hours postoperatively following aspiration during feeding in one child; this child could not be resuscitated. Two children had delayed recovery (2 and 4 hours respectively). The child who had delayed recovery by 2 hours survived and has completed 3 years of follow-up while the other child expired 48 hours later.

CONCLUSION

Simultaneous bilateral primary combined trabeculotomy-trabeculectomy is safe and effective for developmental glaucoma. It obviates the need for long second anaesthesia with its attendant risks. It offers several other benefits to the patients and families.