Willingness to pay for cataract surgery in rural Southern China.

PURPOSE: To study willingness to pay for cataract surgery, and its associations, in Southern China. DESIGN: Cross-sectional willingness-to-pay interview incorporating elements of the open-ended and bidding formats. PARTICIPANTS: Three-hundred thirty-nine persons presenting for cataract screening in Yangjiang, China, with presenting visual acuity (VA) < or = 6/60 in either eye due to cataract. METHODS: Subjects underwent measurement of their VA and a willingness-to-pay interview. Age, gender, literacy, education, and annual income also were recorded. MAIN OUTCOME MEASURES: Maximum amount that the subjects would be willing to pay for cataract surgery. RESULTS: Among 325 (95.9%) subjects completing the interview, 169 (52.0%) were 70 years or older, 213 (65.5%) were women, and 217 (66.8%) had an annual income of <5000 renminbi (5000 = US 625 dollars). Eighty percent (n = 257) of participants were willing to pay something for surgery (mean, 442+/-444 renminbi [US 55 dollars+/-55]). In regression models, older subjects were willing to pay less (8 renminbi [US 1 dollar] per year of age; P = 0.01). Blind subjects were significantly more likely (odds ratio, 5.7; 95% confidence interval, 1.7-19.3) to pay anything for surgery, but would pay on average 255 renminbi (US 32 dollars) less (P = 0.004). Persons at the highest annual income level (>10,000 renminbi [US 1250 dollars]) would pay 50 dollars more for surgery than those at the lowest level (<5000 renminbi) (P = 0.0003). The current cost of surgery in this program is 500 renminbi (US 63 dollars). CONCLUSIONS: Sustainable programs will need to attract younger, more well-to-do persons with better vision, while still providing access to the neediest patients.

The effects of sevoflurane and ketamine on intraocular pressure in children during examination under anesthesia

PURPOSE: We studied the effects on intraocular pressure (IOP) of anesthesia administered during examination under anesthesia (EUA) in children. DESIGN: Randomized clinical trial. METHODS: This randomized trial compared IOP after inhaled sevoflurane gas to that after intramuscular ketamine hydrochloride in children undergoing EUA. IOP was measured in 30 eyes with TonoPen XL (Mentor, Inc, Norwell, Massachusetts, USA) as soon as possible after anesthesia induction (T1) and two, four, six, and eight minutes thereafter. At the same times, we recorded systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR). RESULTS: Compared with the mean IOP at T1, IOP in the sevoflurane group was significantly lower for all measurements from two to eight minutes thereafter (mean decrease in IOP: two minutes = 12%, four minutes = 19%; six minutes = 19%; eight minutes = 17%, all P < or = .01). In the ketamine group, mean IOP was not significantly changed from T1 through six minutes, whereas at eight minutes, it was 7% lower (P = .03). SBP and DBP were significantly lower for sevoflurane than for ketamine at all measurements from two minutes onward, and HR was lower for sevoflurane than for ketamine at two, four, and six minutes. CONCLUSIONS: IOP measured after ketamine sedation is more likely to represent the awake IOP than that after sevoflurane anesthesia. Changes in SBP, DBP, and HR caused by sevoflurane suggest that hemodynamic alterations may underlie its effects on IOP.

The TRAVATAN Dosing Aid accurately records when drops are taken.

PURPOSE:

To assess the accuracy of Travatan Dosing Aid recordings.

DESIGN:

Prospective evaluation of drop-recording accuracy.

METHODS:

Physicians and patients used the Dosing Aid, and logs of usage were compared to the data obtained from the Dosing Aid.

RESULTS:

Five physicians and 20 patients participated. Devices used by physicians recorded all drops dispensed. Extra readings were recorded when physicians carried the devices during the day. For patients, 93% of all drops were recorded, with 18 of 20 subjects having over 85% of the drops recorded. Seventy percent of patients would continue using the device.

CONCLUSIONS:

The Dosing Aid accurately recorded most eyedrops administered by patients and physicians. Given recent documentation of widespread under-compliance with medical therapy, the Dosing Aid could be a useful addition to clinical practice and research.

A method of measuring anterior chamber volume using the anterior segment optical coherence tomographer and specialized software.

PURPOSE: To describe and evaluate a new method for measuring anterior chamber volume (ACV). DESIGN: Observational case series. METHODS: The authors measured ACV using the anterior chamber (AC) optical coherence tomographer (OCT) and applied image-processing software developed by them. Repeatability was evaluated. The ACV was measured in patient groups with normal ACs, shallow ACs, and deep ACs. The volume difference before and after laser peripheral iridotomy (LPI) was analyzed for the shallow and deep groups. RESULTS: Coefficients of repeatability for intraoperator, interoperator, and interimage measurements were 0.406%, 0.958%, and 0.851%, respectively. The limits of agreement for intraoperator and interoperator measurement were -0.911 microl to 1.343 microl and -7.875 microl to -2.463 microl, respectively. There were significant ACV differences in normal, shallow, and deep AC eyes (P < .001) and before and after LPI in shallow AC (P < .001) and deep AC (P = .008) eyes. CONCLUSIONS: The ACV values obtained by this method were repeatable and in accord with clinical observation.

The association between refractive cutoffs for spectacle provision and visual improvement among school-aged children in South Africa.

OBJECTIVES: To evaluate different refractive cutoffs for spectacle provision with regards to their impact on visual improvement and spectacle compliance. DESIGN: Prospective study of visual improvement and spectacle compliance. PARTICIPANTS: South African school children aged 6-19 years receiving free spectacles in a programme supported by Helen Keller International. METHODS: Refractive error, age, gender, urban versus rural residence, presenting and best-corrected vision were recorded for participants. Spectacle wear was observed directly at an unannounced follow-up examination 4-11 months after initial provision of spectacles. The association between five proposed refractive cutoff protocols and visual improvement and spectacle compliance were examined in separate multivariate models. MAIN OUTCOMES: Refractive cutoffs for spectacle distribution which would effectively identify children with improved vision, and those more likely to comply with spectacle wear. RESULTS: Among 8520 children screened, 810 (9.5%) received spectacles, of whom 636 (79%) were aged 10-14 years, 530 (65%) were girls, 324 (40%) had vision improvement > or = 3 lines, and 483 (60%) were examined 6.4+/-1.5 (range 4.6 to 10.9) months after spectacle dispensing. Among examined children, 149 (31%) were wearing or carrying their glasses. Children meeting cutoffs < or = -0.75 D of myopia, > or = +1.00 D of hyperopia and > or = +0.75 D of astigmatism had significantly greater improvement in vision than children failing to meet these criteria, when adjusting for age, gender and urban versus rural residence. None of the proposed refractive protocols discriminated between children wearing and not wearing spectacles. Presenting vision and improvement in vision were unassociated with subsequent spectacle wear, but girls (p < or = 0.0006 for all models) were more likely to be wearing glasses than were boys. CONCLUSIONS: To the best of our knowledge, this is the first suggested refractive cutoff for glasses dispensing validated with respect to key programme outcomes. The lack of association between spectacle retention and either refractive error or vision may have been due to the relatively modest degree of refractive error in this African population.

Targeting relatives of patients with primary open angle glaucoma: the help the family glaucoma project.

PURPOSE:

To assess the knowledge of patients with open angle glaucoma (OAG) and their family members about OAG risk factors and to study the referral of family members for eye examinations.

DESIGN:

Cross-sectional survey and prospective cohort study.

METHODS:

We interviewed OAG patients (probands) at the Wilmer Eye Institute and their biologically related parents, siblings, and children about their knowledge of OAG risk factors. Qualified family members were offered an eye examination through the EyeCare America program. Three months after initial contact, a follow-up telephone questionnaire determined the outcome of the referral.

RESULTS:

Among 102 probands and 100 (of 230 eligible) family members who were interviewed, there was high awareness that OAG is related to older age (85% both groups). More probands knew of the association with higher intraocular pressure (95%) compared with family (78%). Yet, 21% of both groups were not aware that OAG is hereditary, and only 53% of probands and 30% of family members knew that OAG is more common in certain ethnic groups. Only two-thirds of probands had suggested that family members have an eye examination. Eighty percent of family members had had an eye examination within the last year; of 21 with no recent examination, 66% (13/21) accepted referral.

CONCLUSIONS:

The Help the Family Glaucoma project developed a novel approach to identify those at high-risk for OAG. Screening of relatives of OAG patients deserves further study in a more representative selection of the general population.

Determinants of pediatric cataract program outcomes and follow-up in a large series in Mexico.

PURPOSE:

To report determinants of outcomes and follow-up in a large Mexican pediatric cataract project.

SETTING:

Hospital Luis Sanchez Bulnes, Mexico City, Mexico.

METHODS:

Data were collected prospectively from a pediatric cataract surgery program at the Hospital Luis Sanchez Bulnes, implemented by Helen Keller International. Preoperative data included age, sex, baseline visual acuity, type of cataract, laterality, and presence of conditions such as amblyopia. Surgical data included vitrectomy, capsulotomy, complications, and use of intraocular lenses (IOLs). Postoperative data included final visual acuity, refraction, number of follow-up visits, and program support for follow-up.

RESULTS:

Of 574 eyes of 415 children (mean age 7.1 years +/- 4.7 [SD]), IOLs were placed in 416 (87%). At least 1 follow-up was attended by 408 patients (98.3%) (mean total follow-up 3.5 +/- 1.8 months); 40% of eyes achieved a final visual acuity of 6/18 or better. Children living farther from the hospital had fewer postoperative visits (P = .04), while children receiving program support had more visits (P = .001). Factors predictive of better acuity included receiving an IOL during surgery (P = .04) and provision of postoperative spectacles (P = .001). Predictive of worse acuity were amblyopia (P = .003), postoperative complications (P = .0001), unilateral surgery (P = .0075), and female sex (P = .045).

CONCLUSIONS:

The results underscore the importance of surgical training in reducing complications, early intervention before amblyopia (observed in 40% of patients) can develop, and vigorous treatment if amblyopia is present. The positive impact of program support on follow-up is encouraging, although direct financial support may pose a problem for sustainability. More work is needed to understand reasons for worse outcomes in girls.

Visual outcomes and astigmatism after sutureless, manual cataract extraction in rural China: study of cataract outcomes and up-take of services (SCOUTS) in the caring is hip project, report 1.

OBJECTIVE: To study the visual acuity and astigmatism of persons undergoing cataract extraction by local surgeons in rural China. METHODS: Visual acuity, keratometry, and refraction were measured 10 to 14 months postoperatively for all cataract cases during 4 months in Sanrao, China. RESULTS: Among 313 eligible subjects, 242 (77%) could be contacted, of whom 176 (73%) were examined. Of those who were examined, mean +/- SD age was 69.3 +/- 10.5 years, 66.5% were female, 35 had been operated on bilaterally at Sanrao, and 85.2% had a preoperative presenting visual acuity of 6/60 or worse. Presenting and best-corrected postoperative acuity in the eye that was operated on were 6/18 or better in 83.4% and 95.7%, respectively. Among 27 fellow eyes operated on elsewhere, 40.7% had a presenting acuity of 6/18 or better and 40.7% were blind (P < .001). Mean +/- SD postoperative astigmatism did not differ between 211 eyes that were operated on (-1.13 +/- 0.84 diopters) and 109 eyes that were not (-1.13 +/- 1.17 diopters; P = .27). Presence of operative complications (8.5%) and older age were associated with worse vision; bilateral surgery was associated with better vision. CONCLUSIONS: These results confirm the effectiveness of skill transfer in this setting, with superior outcomes to most studies in rural Asia and to eyes in this cohort operated on at other facilities.

Visual function and postoperative care after cataract surgery in rural China: study of cataract outcomes and up-take of services (SCOUTS) in the caring is hip project, report 2.

OBJECTIVE:

To study the postoperative visual function and uptake of refraction and second-eye surgery among persons undergoing cataract surgery in rural China.

METHODS:

Self-reported visual function was measured 10 to 14 months after surgery. Subjects with improvement of 2 or more lines with refraction were offered glasses, and those with significant cataract were offered second-eye surgery.

RESULTS:

Among 313 eligible subjects, 242 (77%) could be contacted; 176 (73%) of those contacted were examined. Interviewed subjects had a mean +/- SD age of 69.9 +/- 10.2 years, and 63.6% were female. The mean +/- SD visual function score was 88.4 +/- 12.3, higher than previously reported for cataract programs in rural China and significantly (P = .03) correlated with presenting vision. Forty-two percent of subjects had spectacles, more than half being reading glasses. Though 87% of subjects' vision improved with refraction, only 35% accepted prescriptions, the most common reason for refusal being lack of perceived need. Second-eye surgery was accepted by a total of 48% (85 of 176) of patients, cost being the biggest reason for refusal.

CONCLUSIONS:

Visual function was high in this cohort. Potential benefit of refraction and second-eye surgery was substantial, but uptake of services was modest. Programs to improve service uptake should focus on reading glasses and cost-reduction strategies such as tiered pricing.

Correction of moderate myopia is associated with improvement in self-reported visual functioning among Mexican school-aged children.

PURPOSE: To quantify the impact on self-reported visual functioning of spectacle provision for school-aged children in Oaxaca, Mexico. METHODS: The Refractive Status Vision Profile (RSVP), a previously validated tool to measure the impact of refractive correction on visual functioning, was adapted for use in rural children and administered at baseline and 4 weeks (27.3 +/- 4.4 days) after the provision of free spectacles. Visual acuity with and without correction, age, sex, and spherical equivalent refraction were recorded at the time of follow-up. RESULTS: Among 88 children (mean age, 12 years; 55.7% girls), the median presenting acuity (uncorrected or with original spectacles), tested 4 weeks after the provision of free spectacles, was 6/9 (range, 6/6-6/120). Significant improvements in the following subscales of the RSVP were seen for the group as a whole after the provision of free spectacles: function, 11.2 points (P = 0.0001); symptoms, 14.3 points (P < 0.0001); total score, 10.3 points (P = 0.0001). After stratification by presenting vision in the better-seeing eye, children with 6/6 acuity (n = 22) did not have significant improvement in any subscale; those with acuity of 6/7.5 to 6/9 (n = 34) improved only on function (P = 0.02), symptoms (P = 0.005), and total score (P = 0.003); and those with acuity of 6/12 or worse improved on total score (P < 0.0001) and all subscales. Subjects (n = 31) with uncorrected myopia of -1.25 D or more had a mean improvement in total score of 15.9 points (P < 0.0001), whereas those with uncorrected myopia between -0.50 and -1.00 D inclusive (n = 53) had a mean improvement of 8 points (P = 0.01). CONCLUSIONS: Provision of spectacles to children in this setting had a significant impact on self-reported function, even at modest levels of baseline visual disability. The correlation between presenting vision/refraction and improvement and the failure of children 6/6 at baseline to improve offer evidence for a real effect.

Ocular comorbidities among cataract-operated patients in rural China: the caring is hip Study of Cataract Outcomes and Uptake of Services (SCOUTS), report No. 3.

PURPOSE: To determine the prevalence and impact on vision and visual function of ocular comorbidities in a rural Chinese cataract surgical program, and to devise strategies to reduce their associated burden. DESIGN: Cross-sectional cohort study. PARTICIPANTS: Persons undergoing cataract surgery by one of two recently trained local surgeons at a government-run village-level hospital in rural Guangdong between August 8 and December 31, 2005. INTERVENTIONS: Eligible subjects were invited to return for a comprehensive ocular examination and visual function interview 10 to 14 months after surgery. Prevalent ocular comorbid conditions were identified. MAIN OUTCOME MEASURES: Presenting and best-corrected vision, visual function, and treatability of the comorbidity. RESULTS: Of 313 persons operated within the study window, 242 (77%) could be contacted by telephone; study examinations and interviews were performed on 176 (74%). Examined subjects had a mean age of 69.4+/-10.5 years, 116 (66%) were female, and 149 (85%) had been blind (presenting vision < or = 6/60) in the operative eye before surgery. Among unoperated eyes, 89 of 109 (81.7%) had > or =1 ocular comorbidities, whereas for operated eyes the corresponding proportion was 72 of 211 (34.1%). The leading comorbidity among operated eyes was refractive error (43/72 [59.7%]), followed by glaucoma/glaucoma suspect (14/72 [19.4%]), whereas for unoperated eyes, it was cataract (80/92 [87.0%]), followed by refractive error (12/92 [13.0%]). Among operated eyes with comorbidities, 90.3% (65/72) had > or =1 comorbidities that were treatable. In separate models adjusting for age and gender, persons with > or =1 comorbidities in the operated eye had significantly worse presenting vision (P<0.001) than those without such findings, but visual function (P = 0.197) and satisfaction with surgery (P = 0.796) were unassociated with comorbidities. CONCLUSIONS: Ocular comorbidities are highly prevalent among persons undergoing cataract surgery in this rural Asian setting, and their presence is significantly associated with poorer visual outcomes. The fact that the great majority of comorbidities encountered in this program are treatable suggests that strategies to reduce their impact can be successful.

Distribution and visual impact of postoperative refractive error after cataract surgery in rural China: study of cataract outcomes and up-take of services report 4.

PURPOSE: To model the possible impact of using average-power intraocular lenses (IOLs) and evaluate the postoperative refractive error in patients having cataract surgery in rural China.SETTING: Rural Guangdong, China.METHODS: Patients having cataract surgery by local surgeons were examined and visual function was assessed 10 to 14 months after surgery. Subjective refraction at near and distance was performed bilaterally by an ophthalmologist. Patients had a target refraction of -0.50 diopter (D) based on ocular biometry.RESULTS: Of the 313 eligible patients, 242 (77%) could be contacted and 176 (74% of contacted patients, 56% overall) were examined. Examined patients had a mean age of 69.4 +/- 10.5 years. Of the 211 operated eyes, 73.2% were within +/-1.0 D of the target refraction after surgery. The best presenting distance vision was in patients within +/-1.0 D of plano and the best presenting near vision, in those with mild myopia (<-1.0 D to > or =2.0 D) (P= .005). However, patients with hyperopia (>+1.0 D) reported significantly better adjusted visual function than those with emmetropia or myopia (<-1.0 D). When the predicted use of an average-power IOL (median +21.5 D) was modeled, predicted visual acuity was significantly reduced (P= .001); however, predicted visual function was not significantly altered (P>.3).CONCLUSIONS: Accurate selection of postoperative refractive error was achieved by local surgeons in this rural area. Based on visual function results, aiming for mild postoperative myopia may not be suitable in this setting. Implanting average-power IOLs significantly reduced postoperative presenting vision, but not visual function.

Influence of corneal structure, corneal responsiveness, and other ocular parameters on tonometric measurement of intraocular pressure.

PURPOSE: To estimate the relationships between ocular parameters and tonometrically measured intraocular pressure (IOP), to determine the influence of ocular parameters on different instrument measurements of IOP, and to evaluate the association of ocular parameters with a parameter called hysteresis. METHODS: Patients presenting at a glaucoma clinic were recruited for this study. Subjects underwent IOP measurement with the Goldmann applanation tonometer (GAT), the TonoPen, and the Reichert Ocular Response Analyzer (ORA), and also measurements of central corneal thickness (CCT), axial length, corneal curvature, corneal astigmatism, central visual acuity, and refractive error. Chart information was reviewed to determine glaucoma treatment history. The ORA instrument provided a measurement called corneal hysteresis. The association between measured IOP and the other ocular characteristics was estimated using generalized estimating equations. RESULTS: Among 230 patients, IOP measurements from the TonoPen read lowest, and ORA read highest, and GAT measurements were closest to the mean IOP of the 3 instruments. In a multiple regression model adjusting for age, sex, race, and other ocular characteristics, a 10 microm increase in CCT was associated with an increase of 0.79 mm Hg measured IOP in untreated eyes (P<0.0001). Of the 3 tonometers, GAT was the least affected by CCT (0.66 mm Hg/10 mum, P<0.0001). Hysteresis was significantly correlated with CCT with a modest correlation coefficient (r=0.20, P<0.0007). CONCLUSIONS: Among parameters related to measured IOP, features in addition to CCT, such as hysteresis and corneal curvature, may also be important. Tonometric instruments seem to be affected differently by various physiologic characteristics.

Traffic gap judgment in people with significant peripheral field loss.

PURPOSE: Subjects with significant peripheral field loss (PFL) self report difficulty in street crossing. In this study, we compared the traffic gap judgment ability of fully sighted and PFL subjects to determine whether accuracy in identifying crossable gaps was adversely affected because of field loss. Moreover, we explored the contribution of visual and nonvisual factors to traffic gap judgment ability. METHODS: Eight subjects with significant PFL as a result of advanced retinitis pigmentosa or glaucoma with binocular visual field <20 degrees and five age-matched normals (NV) were recruited. All subjects were required to judge when they perceived it was safe to cross at a 2-way 4-lane street while they stood on the curb. Eye movements were recorded by an eye tracker as the subjects performed the decision task. Movies of the eye-on-scene were made offline and fixation patterns were classified into either relevant or irrelevant. Subjects' street-crossing behavior, habitual approach to street crossing, and perceived difficulties were assessed. RESULTS: Compared with normal vision (NV) subjects, the PFL subjects identified 12% fewer crossable gaps while making 23% more errors by identifying a gap as crossable when it was too short (p < 0.05). The differences in traffic gap judgment ability of the PFL subjects might be explained by the significantly smaller fixation area (p = 0.006) and fewer fixations distributed to the relevant tasks (p = 0.001). The subjects' habitual approach to street crossing and perceived difficulties in street crossing (r > 0.60) were significantly correlated with traffic gap judgment performance. CONCLUSIONS: As a consequence of significant field loss, limited visual information about the traffic environment can be acquired, resulting in significantly reduced performance in judging safe crossable gaps. This poor traffic gap judgment ability in the PFL subjects raises important concerns for their safety when attempting to cross the street.