Emmy Y. Li

Descemet Stripping Endothelial Keratoplasty: Effect of the Surgical Procedure on Corneal Optics

PURPOSE To determine the changes in corneal optical performance after posterior lamellar corneal transplantation. DESIGN Retrospective case series. METHODS The anterior segment in four eyes of four patients who underwent Descemet stripping endothelial keratoplasty (DSEK) with cataract extraction and intraocular lens (IOL) implantation were imaged with the Visante anterior segment optical coherence tomography [OCT] (Carl Zeiss Meditec, Dublin, California, USA). The curvature of the posterior surface of the donor graft was compared with that of the host cornea, and corneal thickness was measured. RESULTS All eyes had a hyperopic refractive error after surgery. The posterior corneal curvature after surgery was more than that before surgery. Average preoperative keratometry was 43.4 diopters (D), and after surgery, it was 42.8 D using keratometry. However, when the postsurgical corneal power was calculated using the Gaussian optics method, the average value was 40.8 D. CONCLUSIONS The addition of a donor corneal graft to the posterior surface of decompensated corneas may lessen the effective optical power of the cornea and may have implications for IOL power calculations in these eyes.

Comparison of Outcomes of Primary Anterior Chamber Versus Secondary Scleral-Fixated Intraocular Lens Implantation in Complicated Cataract Surgeries

PURPOSE To compare the outcome of primary anterior chamber vs secondary scleral-fixated intraocular lens (IOL) implantation in complicated cataract surgeries. DESIGN Retrospective, comparative study. METHODS A consecutive series of complicated cataract surgeries with primary anterior chamber (ACIOL) or secondary scleral-fixated IOL implantation from January 1, 2004 to December 31, 2009 was analyzed. Main outcome measures included the postoperative best-corrected visual acuity (BCVA) and postoperative complications. RESULTS There were 89 eyes in the primary ACIOL group and 74 eyes in the secondary scleral-fixated IOL group. The mean follow-up duration was 64.1 ± 36.7 months. The mean postoperative logarithm of minimal angle of resolution (logMAR) BCVA at 1 year was 0.32 ± 0.54 and 0.34 ± 0.21 in the primary ACIOL group and the secondary scleral-fixated IOL group, respectively (P = .734). The mean latest logMAR BCVA was 0.68 ± 0.54 and 0.61 ± 0.47 in the primary ACIOL group and the secondary scleral-fixated IOL group, respectively (P = .336). The primary ACIOL group had more early postoperative complications (P < .001). No difference in late postoperative complications was observed between the 2 groups (P = .100). Regression analysis showed that primary ACIOL and secondary scleral-fixated IOL implantation had similar latest postoperative logMAR BCVA (P = .927), while the presence of late complications was associated with a worse final visual outcome (P = .000). CONCLUSIONS This study shows that there are no long-term differences in the visual outcomes and complication profiles after primary ACIOL or secondary scleral-fixated IOL implantation in a complicated cataract operation when capsular support is inadequate.

Orthokeratology-Associated Infectious Keratitis in a Tertiary Care Eye Hospital in Hong Kong

PURPOSE To analyze cases of orthokeratology-associated infectious keratitis managed in a tertiary care eye hospital in Hong Kong between 2003 and 2013. DESIGN Retrospective study. METHODS Case records of patients with infectious keratitis attributable to orthokeratology contact lenses were analyzed. Data analyzed included clinical features, microbiological evaluation, and treatment outcomes. RESULTS A total of 23 patients were included (16 female, 7 male, mean age: 15.0 ± 4.2 years; range: 9-23 years). All patients were using overnight orthokeratology for an average of 2.7 ± 2.8 years (range: 3 months - 10 years) before the onset of infection. Clinical features included corneal infiltrate (n = 14, 60.9%) and corneal perineuritis (n = 12, 52.2%). Fifteen eyes (65.2%) had a positive microbiological culture obtained from corneal scrapings. The most commonly isolated organism was Pseudomonas aeruginosa (n = 6), followed by coagulase-negative Staphylococcus (n = 5) and Acanthamoeba (n = 3). Five cases of Pseudomonas aeruginosa and 5 cases of Acanthamoeba were identified from contact lenses or contact lens solution. The mean duration from disease onset to remission was 31.9 ± 34.9 days (range: 6-131 days). All patients responded to medical treatment, and no emergency surgical intervention was needed. The best-corrected logMAR visual acuity improved significantly from 0.62 ± 0.51 (20/83 Snellen) to 0.15 ± 0.20 (20/28 Snellen) (Wilcoxon signed rank test, P < .001). CONCLUSIONS Orthokeratology-associated infectious keratitis continues to be a serious problem, especially in regions with high prevalence of myopia. Early clinical and microbiological diagnosis and intensive treatment can improve final visual outcomes.

In vivo measurements of macular and nerve fibre layer thickness in retinal arterial occlusion.

AimTo investigate the structure–function relationship in patients with retinal arterial occlusion by measuring the macular and the peripapillary retinal nerve fibre layer (RNFL) thickness and the visual sensitivity.MethodsThis is an observational case series with three patients with central retinal arterial occlusion (CRAO) and two patients with branch retinal arterial occlusion (BRAO). The macular/peripapillary RNFL thickness and the visual field were measured with Stratus optical coherence tomography (OCT) and Humphrey visual field analyzer, respectively, at least 1 year after the diagnosis of CRAO or BRAO.ResultsThe macular thickness, in particular the inner retinal layer, and the peripapillary RNFL thickness were reduced in patients with retinal arterial occlusion. The decrease in the macular and the peripapillary RNFL thickness corresponded to the sites of retinal arterial occlusion with diffuse and segmental thinning found in CRAO and BRAO, respectively. Visual field defects were found in the corresponding locations of macular and RNFL thinning, and closely correlated with the degree of the structural damage.ConclusionsStructural damages in terms of reduction in the macular and peripapillary RNFL thickness were evident in patients with retinal arterial occlusion. A close structure–function correlation was found and a worse functional outcome is associated with a more extensive thinning of the macula and RNFL. OCT measurements of the macular/peripapillary RNFL thickness provide useful indicators to reflect the severity of the disease in retinal arterial occlusion and serve as a new paradigm to study and monitor the disease longitudinally.

Prevalence of blindness and outcomes of cataract surgery in Hainan Province in South China.

OBJECTIVE To define the prevalence of blindness and visual impairment (VI) in people in rural Hainan using the rapid assessment of avoidable blindness (RAAB) and to report the outcomes of cataract surgery among the residents. DESIGN Population-based, cross-sectional survey. PARTICIPANTS A total of 6482 rural residents of the Hainan province. METHODS A total of 136 clusters, each of which consisted of 50 people aged ≥50 years, were selected through probability-proportionate-to-size sampling. Door-to-door visits were performed by 2 outreach teams. Visual acuity (VA) was measured on site, and those with VA <6/18 in either eye were examined by an ophthalmologist. Causes of blindness and VI were determined. The causes of poor visual outcome after cataract surgery were evaluated. Information regarding barriers to receiving surgery was collected by trained interviewers. MAIN OUTCOME MEASURES Prevalence and causes of blindness (VA <3/60), severe VI (SVI) (VA <6/60 but ≥3/60), and VI (VA <6/18 but ≥6/60) based on presenting VA (PVA) were assessed. Outcomes of cataract surgery performed in public and private hospitals and charitable organizations were compared. RESULTS A total of 6482 subjects were examined (response rate, 95.3%). The sample prevalence of blindness was 4.4% (95% confidence interval [CI], 2.0-6.8). The prevalence of SVI and VI was 1.9% (95% CI, 0-4.3) and 9.9% (95% CI, 7.6-12.2), respectively. Age and sex were associated with increased prevalence of blindness, SVI, and VI. Overall, cataract accounted for approximately 60% of blindness and SVI. Of the 524 eyes that had received cataract surgery, 87.2% had intraocular lenses implanted, 21% had a poor visual outcome (PVA <6 /60), and 20% had a borderline visual outcome (PVA <6/18 but ≥6/60). Eyes that received surgery in charitable organizations had a higher rate of intraocular lens implantation and good visual outcome (VA ≥6/18) compared with eyes that were operated on elsewhere. CONCLUSIONS The prevalence of blindness, SVI, and VI was high among rural residents in Hainan. Cataract remained the leading cause of avoidable blindness. Outcomes of cataract surgery performed in public hospitals were suboptimal. Quality-control initiatives should be introduced to improve cataract surgery outcomes.

Barriers for poor cataract surgery uptake among patients with operable cataract in a program of outreach screening and low-cost surgery in rural china

Abstract Aims: To identify the reasons for poor uptake of cataract surgery in a program of outreach screening and low-cost surgery in Pucheng County, a rural area in northwestern China. Methods: Detailed interviews with a semi-structured questionnaire were conducted by telephone or face-to-face for participants who had been advised to attend a low-cost cataract surgery program but did not schedule the surgery within 3 months after the initial screening. Results: Among 432 eligible subjects, 355 (82.2%) were interviewed (mean age 70.6 ± 6.6 years, 73.8% female). A total of 138 subjects (38.9%) were interviewed by phone and 217 (61.1%) were interviewed face-to-face. Lack of family support (n = 106, 29.9%) and failure to understand the need for surgery (n = 96, 27.0%) were the two main reasons for not undergoing cataract surgery. Other factors included fear of surgery (n = 62, 17.5%), lack of faith in doctors (n = 36, 10.1%), financial constraints (n = 25, 7.0%) and lack of transportation (n = 4, 1.1%). Conclusion: The principal barriers to low-cost cataract surgery uptake in rural China included lack of family support and failure to understand the need for surgery. Education targeting entire families to eliminate these barriers and development of community support systems at the family level are required to achieve greater uptake of low-cost cataract surgery programs in rural China.

Project vision: a new and sustainable model for eliminating cataract blindness in China.

Cataract is by far the most common cause of major vision loss, accounting for approximately half of all global blindness. According to the World Health Organization (WHO), roughly 18 million people worldwide are bilaterally blind from cataract. These sobering statistics have a profound societal economic impact through the combined loss of productivity of both the blind and those who must care for them. This, and the significant reduction of life expectancy for the blind, makes sight restoring cataract surgery one of society’s most cost-effective medical interventions. It is estimated that increased economic productivity during the first postoperative year alone exceeds the cost of the surgery by a factor of 15. The costly societal burden of cataract blindness is not for lack of an effective treatment, as residents of all developed countries enjoy the hi-tech miracle of modern cataract surgery. Instead, cataract blindness results from the sizable gap in health-care delivery between affluent and poor societies. Cataract remains the leading cause of blindness in developing countries where the significant shortage of ophthalmologists and eye surgical services is the chief, but not sole cause. Yorston highlighted four additional major obstacles that deter people from receiving cataract surgery in developing countries. These barriers are (i) a lack of awareness about cataract and its treatment, (ii) a negative perception of the quality of locally available health services, (iii) problems with transportation to health-care facilities, and (iv) the inability to afford the direct and indirect costs arising from surgery. During the past three decades, China’s explosive economic growth and development have been apparent and impressive to all. However, the benefits of this extraordinary economic transformation have been largely reaped in China’s urban centres, and have not been shared by the rural population. Perhaps in no area is this gap in living standard more apparent than in health care. An important public health statistic is the so-called, cataract surgical rate (CSR), which represents the number of cataract operations annually performed per one million of population. As would be expected, the highest rates are seen in those countries with the highest gross domestic product (GDP) (Table 1). Astonishingly, however, China’s CSR is among the lowest in the world, and on a par with African countries with extremely low GDPs. This glaring discrepancy is all the more disappointing considering that economic reforms have resulted in a 10-fold rise in China’s GDP since 1978. An epidemiological survey in the late 1980s estimated that at least 5 million people suffered from bilateral blindness in China, and that cataract was responsible for 50% of these cases. According to the WHO, in developing countries a CSR of 1000 is necessary simply to treat the new cases of cataract blindness arising every year. For China, the current population of 1.3 billion, translates into 1.3 million new cases of cataract blindness per year. With such a deficient CSR, China’s burden of cataract blindness will continue to grow at an epidemic rate until access to surgery can be increased. To underscore the severity of the problem, even a tripling of China’s current CSR would barely make a dent in the country’s huge backlog of cataract blindness.

Cost-effectiveness of treating normal tension glaucoma.

PURPOSE To assess the long-term cost-effectiveness of treating normal tension glaucoma (NTG). METHODS A Markov decision-analytic health model was developed to determine the cost-effectiveness of treating NTG with IOP lowering therapy to prevent progressive visual field loss. Transitional probabilities were derived from the Collaborative Normal Tension Glaucoma Study and cost data obtained from the literature and the Medicare fee schedule. Incremental cost-effectiveness ratios (ICER) of treating all patients with NTG and treating selected individuals with risk factors for disease progression were determined using Monte Carlo simulation. Sensitivity analyses were performed by varying the cost of consultations, medications, laser/surgery, and adjusting utility loss from progressed states. RESULTS The ICER of treating all patients with NTG over a 10-year period was United States (US)

Balloon dacryoplasty in internal ostium stenosis after endoscopic dacryocystorhinostomy.

34,225 per quality-adjusted life year (QALY). The ICER would be reduced when treatment was offered selectively to those with risk factors for disease progression. The ICER for treating NTG patients with disc hemorrhage, migraine, and those who were female were US

Long-term outcomes of punch punctoplasty with Kelly punch and review of literature.

24,350, US