How close are we? An audit of biometry of a tertiary care hospital in Karachi.

OBJECTIVE: To evaluate the accuracy of biometry in the post-op phase of cataract surgery. METHODS: This study was conducted at Liaquat National Hospital, Karachi, from June 2015 to July 2016, and comprised the audit of patients who underwent cataract surgery during the period. Keratometry was done on Haag-Strait manual keratometer and A-scan was done by applanation contact method on SonoMed machine. Theoretic-T formula was used to calculate desired intraocular lens power for all kinds of axial lengths. A single surgeon operated upon the same Alcon Constellation phacoemulsification machine. Postoperative follow-up was done by monitoring auto refraction and visual acuity on days 1, 7, 30 and 90. SPSS 21 was used for data analysis.. RESULTS: Of 244 patients, 121(49.60%) were males and 123(50.40%) were females. There were 123(50.40%) right eyes and 121(49.60%) left eyes. Overall, 132(54.10%) achieved postoperative refraction within ±0.5 D of target and 193(79.10%) within ±1 D of target. Age, gender and laterality had no significant effect on outcomes (p>0.05 each). CONCLUSIONS: Postoperative refraction corresponded quite closely with global recommendations.

Refractive results after implantation of a light-adjustable intraocular lens in postrefractive surgery cataract patients.

PURPOSE: To evaluate whether postoperative refractive power adjustment of a light-adjustable lens (LAL; Calhoun Vision, Inc, Pasadena, CA) improves refractive outcomes in patients who have undergone prior LASIK or photorefractive keratectomy. DESIGN: Retrospective case series. PARTICIPANTS: Thirty-four eyes in 21 cataract patients with a mean age of 62.6 ± 9.7 years and a history of myopic corneal refractive surgery were implanted with the LAL during cataract surgery performed at a single clinic in Victoria, Canada. METHODS: Two weeks after uncomplicated cataract surgery, we used a light delivery device to deliver a spatially resolved 365-nm beam of ultraviolet light to alter the shape of the LAL and hence its refractive power. To obtain the desired refractive change, 1, 2, or 3 adjustments were used. After adjustments, we applied 2 lock-in treatments to the LAL to consume unpolymerized macromeres in the LAL. The final manifest refraction spherical equivalent (MRSE) achieved then was compared with the initial refractive target before LAL implantation. MAIN OUTCOME MEASURES: The MRSE to target refraction, mean absolute error of cohort to target refraction, and percentage of cohort within ± 0.25 diopters (D), ± 0.50 D, ± 1.0 D, and more than ± 1.0 D relative to target refraction. RESULTS: The MRSE relative to target refraction after final lock-in was within ± 0.25 D in 74% of eyes, within ± 0.50 D in 97% of eyes, and within ± 1.00 D in 100% of eyes. Mean absolute error was 0.19 D with a standard deviation of ± 0.20 D. CONCLUSIONS: In patients with a history of laser refractive surgery, LAL implantation and postimplantation adjustment provide a precise refractive outcome. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Efficacy and safety of mass cataract surgery campaign in a developing country.

PURPOSE: To determine the visual outcomes achieved in terms of efficacy and safety during a mass eye surgery campaign in a low-income developing country. METHODS: Three hundred fifteen eyes of 305 patients underwent extracapsular cataract extraction with intraocular lens implantation in a prospective, analytical, experimental, and nonrandomized study on patients who underwent cataract surgery during the campaign that two Spanish nongovernmental organizations conducted in December 2008 in a district hospital in Bobo-Dioulasso (Burkina Faso). RESULTS: Mean age was 61.97 ± 14.39 years. The mean uncorrected distance visual acuity before surgery was 2.17 ± 0.7 (20/3000), which improved to 0.86 ± 0.64 logMAR (20/150) 3 months after cataract surgery. The mean spherical equivalent at 3 months was -0.87 ± 1.90 diopters. The corrected distance visual acuity was 0.52 ± 0.44 logMAR (20/60) 3 months after surgery, 68.7% of the patients had good visual outcomes, and 9.16% had poor outcomes. A total of 41.4% of the operated eyes showed a spherical equivalent within ± 1.00 diopter of emmetropia. The most common intraoperative complication was posterior capsule rupture (incidence, 2.9%, 9 of 315), and the most serious complication was expulsive hemorrhage (incidence, 0.3%, 1 of 315). Three months after surgery, 2.9% (9 of 315) of the eyes was affected by posterior capsular opacity. CONCLUSIONS: A mass cataract campaign performed in a developing country with the proper technique and standardized protocols of action improved the visual outcome of the patients. The rate of incidence of extracapsular extractions is comparable to that estimated for developed countries.

[Presbyopia correction using accommodating intraocular lens].

Clinical results of binocular implantation of intraocular lens (IOL) Crystalens HD500 are assessed in 25 patients (mean age 62, 7 +/- 2,6 years) without severe intraocular diseases. Accommodating capacity of this IOL was showed to be provided by movement along the optic axis and not to exceed 1,0-1,5D, that is not enough to compensate for accommodation amplitude required for comfortable reading without spectacles. Preoperative discussion of lens features with patients, planning of aim-refraction considering minimonovision technique, precise performance of all implantation stages for this IOL model are essential for high visual results and complete satisfaction of a patient.

Artificial accommodating intraocular lens powered by an ion polymer-metal composite actuator.

The current method of controlling the focus of an accommodating intraocular lens is based on ciliary muscle contraction and cannot be used in older patients with presbyopia. We aimed to develop a dynamically accommodating intraocular lens powered by a membrane-shaped ion polymer metal composite actuator that is thin enough to be inserted in the eye. This study addresses two key problems identified in our previous accommodating intraocular lens prototype: the lack of repeatability due to the use of swine lenses instead of artificial lenses and the occurrence of a sixth order aberration. Thus, we present a new accommodating intraocular lens design and a method to transfer energy to actuators. To accommodate lens deformation and depth of focus, we used a membrane-shaped ion polymer metal composite actuator, thin enough to be inserted in the eye, and used an artificial silicone lens. To prevent the sixth order aberration, we included a ring between the ion polymer metal composite actuator and the lens. Different voltage patterns were applied to the IPMC actuator and changes in focus were observed. We were able to obtain repeatability and prevent the sixth order aberration. The dioptric power changed to ±0.23 D when ±1.5 V was used; however, at >1.5 V, a large accommodating range occurred, in addition to astigmatic vision. Thus, we have developed a novel prototype that is completely artificial, allowing reproducible and repeatable results. Visual accommodative demands were successfully met; however, although astigmatic vision was lessened, it was not completely eradicated.

Measuring benefits and patients' satisfaction when glasses are not needed after cataract and presbyopia surgery: scoring and psychometric validation of the Freedom from Glasses Value Scale (FGVS).

BACKGROUND: The purpose of this study was to reduce the number of items, create a scoring method and assess the psychometric properties of the Freedom from Glasses Value Scale (FGVS), which measures benefits of freedom from glasses perceived by cataract and presbyopic patients after multifocal intraocular lens (IOL) surgery. METHODS: The 21-item FGVS, developed simultaneously in French and Spanish, was administered by phone during an observational study to 152 French and 152 Spanish patients who had undergone cataract or presbyopia surgery at least 1 year before the study. Reduction of items and creation of the scoring method employed statistical methods (principal component analysis, multitrait analysis) and content analysis. Psychometric properties (validation of the structure, internal consistency reliability, and known-group validity) of the resulting version were assessed in the pooled population and per country. RESULTS: One item was deleted and 3 were kept but not aggregated in a dimension. The other 17 items were grouped into 2 dimensions ('global evaluation', 9 items; 'advantages', 8 items) and divided into 5 sub-dimensions, with higher scores indicating higher benefit of surgery. The structure was validated (good item convergent and discriminant validity). Internal consistency reliability was good for all dimensions and sub-dimensions (Cronbach's alphas above 0.70). The FGVS was able to discriminate between patients wearing glasses or not after surgery (higher scores for patients not wearing glasses). FGVS scores were significantly higher in Spain than France; however, the measure had similar psychometric performances in both countries. CONCLUSIONS: The FGVS is a valid and reliable instrument measuring benefits of freedom from glasses perceived by cataract and presbyopic patients after multifocal IOL surgery.

Corneal topography in clinical practice.

Developments in corneal topography allow for increasingly precise, detailed analysis of the corneal surface. This test is becoming indispensable in the treatment of complex corneas: keratoconus, corneal transplants, orthokeratology, etc. In refractive surgery, the combined analysis of the anterior and posterior cornea has permitted better screening for forme fruste keratoconus at risk for post-LASIK ectasia. Topography also assists in the calculation of premium intraocular lenses. Topography is an indispensable test for analyzing and following corneal disease.

Keratoprosthesis Decentration and Tilt Results in Degradation in Image Quality.

PURPOSE: To study the effect of decentration and tilt of the type I Boston keratoprosthesis (KPro) on image quality in both aphakic and pseudophakic eyes. METHODS: An optical ray-tracing program was used to simulate the image projected onto the retina in an eye with a perfectly centered KPro, and in eyes with varying degrees of KPro decentration and tilt. Decentration was modeled along a typical white-to-white distance of 12.0 mm, and the corresponding tilt was calculated assuming a radius of curvature of 8.0 mm, the radius of curvature of the backplate of the KPro. Both aphakic and pseudophakic eyes were simulated, and the corresponding modulation transfer function curves, point spread functions, and astigmatism were analyzed. RESULTS: The perfectly centered KPro produced a high-quality image with no induced astigmatism. Increasing decentration beyond approximately 0.5 mm resulted in poorer image quality with a more pronounced effect in the presence of an intraocular lens. Using models of the normal eye as a threshold, image degradation due to decentration becomes clinically significant at approximately 1.4 mm and 0.9 mm for the aphakic and pseudophakic cases, respectively. Astigmatism introduced by decentration is approximately 0.25 D cylinders at those thresholds. CONCLUSIONS: Decentration of up to 0.5 mm had no significant impact on image quality and an attempt at good intraoperative centration of the KPro within this range is important. Conversely, decentration of 0.9 mm or more during surgical implantation can result in significant degradation in retinal image quality including astigmatism. The effect is greater in the pseudophakic eye.

Nine-year follow-up of a posterior chamber phakic IOL in one eye and LASIK in the fellow eye of the same patient.

PURPOSE: To compare the long-term results (9 years) of LASIK in one eye and phakic intraocular lens (implantable contact lens [ICL]) implantation in the fellow eye of the same patient. METHODS: A patient with high myopia underwent LASIK with a MEL 60 excimer laser in one eye (spherical equivalent refraction -9.75 diopters [D], 5-mm optical zone with no transition zone) and phakic intraocular lens (STAAR Collamer implantable contact lens [ICL]) implantation (spherical equivalent refraction -9.50 D) in the fellow eye. RESULTS: At 9 years postoperatively, the mean spherical equivalent refraction was -1.00 in the eye with the ICL and -1.75 D in the eye that underwent LASIK. During the first 6 postoperative months in the LASIK eye, refraction regressed, but remained stable during the remainder of follow-up. Uncorrected visual acuity was 20/25 in the eye with the ICL and 20/30 in the LASIK eye, whereas best spectacle-corrected visual acuity was 20/20 in both eyes. Less night vision problems (glare and halos) were experienced in the eye with the ICL compared to the LASIK eye. Although the patient initially preferred the LASIK procedure, at last follow-up 9 years postoperatively, increased overall satisfaction was reported for the eye with the ICL compared to the LASIK eye. CONCLUSIONS: Nine years after treatment of high myopia with the ICL and LASIK in the same patient, better quality of vision, stability, and satisfaction score were achieved in the eye with the ICL compared to the eye that had undergone LASIK. No long-term sight-threatening complications were found during followup.

Refractive outcomes after primary intraocular lens implantation in infants.

BACKGROUND: Intraocular lens (IOL) implantation is becoming increasingly accepted as a primary procedure in infants. AIM: To evaluate the accuracy of IOL power calculation, the rate of myopic shift and the refractive outcome after primary IOL implantation in infants aged <12 months at the time of cataract surgery. METHOD: A retrospective case review of 25 patients (8 with bilateral cataracts and 17 with unilateral cataracts) who underwent cataract surgery with primary IOL implantation at <12 months of age. Outcomes measured were actual early postoperative refraction, lens power calculation error, myopic shift and refractive outcome. RESULTS: In 83% of cases, actual postoperative refraction was within 2 dioptres (D) of the target refraction. Lens power calculation error did not depend on axial length, age at surgery or target refraction. Mean (SD) myopic shift was 5.43 (3.7) D in the first 12 months after surgery, but was significantly greater when surgery was performed at <10 weeks of age. CONCLUSION: This study demonstrates that IOL power can be calculated with reasonable accuracy in infants using current formulas. Factors such as age at the time of surgery, axial length, whether surgery is unilateral or bilateral, and the presence of systemic pathologies do not seem to influence the accuracy of lens power calculation or myopic shift up to 36 months of age.

[Assessment of clinical practice guidelines about cataract management]. / Evaluación de guías de práctica clínica sobre catarata.

PURPOSE: To evaluate the quality of clinical practice guidelines (CPG) about the management of cataract in adults. MATERIAL AND METHOD: A bibliographic search was carried out selecting the CPG based on the evidence or on the expert consensus, published since the year 2000. The guidelines selected were assessed with the AGREE Instrument. RESULTS: Six guidelines were assessed. Three were classified as "recommend with provisos or alterations" and the others "would not be recommended". In accordance with the AGREE Instrument criteria, no guidelines can be recommended for their use in the clinical practice if they were not modified previously.

Audit of exracapsular cataract extraction with posterior chamber intraocular lens implantation in a tertiary eye care center in Ethiopia.

A retrospective audit of records of 370 eyes of 315 patients for whom extracapsular cataract extraction with posterior chamber intraocular lens implantation (ECCE-PC IOL) was performed between 1998 and 1999 was made to determine postoperative visual outcome and complications. One hundred and ninety three patients were males and one hundred and seventy seven were females making a male to female ratio of 1:0.9. At two months postoperatively 82 (30.4%) of eyes had uncorrected visual acuity of 6/18 or better; while 176 (53.7%) of eyes attained an uncorrected visual acuity between 6/18 and 6/60, and 31 (11.5%) had visual acuity between 3/60 and 6/60. 340 of 358 (94.9%) had a preoperative visual acuity of < 3/60. As a result of the surgery, the percentage of blind eyes dropped from 94.9% to 4.4%. The commonest intra operative and early postoperative complications encountered were posterior capsular tear with vitreous loss (5.7%) and striate keratopathy (11.1%) respectively. Posterior capsular opacity was documented in 17 (4.6%) eyes as a late postoperative complication. Routine biometry, to calculate Intra ocular Lens (IOL) power was not done and this was the major limitation of the study. In conclusion, the study increases awareness of cataract surgery outcomes and provides a feedback to achieve better results both in terms of quality and quantity in cataract surgery. Further study with biometric measurement is recommended.

Searching the way out for posterior capsule opacification.

Searching the way out for posterior capsule opacification was one of our goals in improving current cataract surgery techniques. The second goals was restoring accommodation but this goal prooved to remain unsolved. The bag-in-the-lens concept of IOL and implantation technique has been used in 271 patients of which 15 children. These patients have a follow-up of one month to 5 years. The optical axis of all these patients remained crystal clear, which allows us to conclude that the problem of PCO is solved by the bag-in-the-lens implantation concept. These very encouraging results inspired us to new ideas, which will receive priority in our research: accommodation and optimising the quality of vision by compensating for the ocular aberrations.

Current trends in cataract surgery in Thailand--2004 survey.

OBJECTIVES: To survey and investigate the current trend of cataract surgery in Thai ophthalmologists in 2004. MATERIAL AND METHOD: Questionnaires were sent to 600 ophthalmologists who were the members of the Ophthalmological Society and Royal Colleges of Ophthalmologists of Thailand. Data received from 248 (41.3%) of the recipients were analyzed and compared with those from the previous survey. RESULTS: The majority of respondents were male (63.3%) while 36.7% were female. In cataract surgery, 99.2% were still doing cataract surgery, the average number of cataract surgery procedures per surgeon per month was 25.6, 89.8% preferred phacoemulsification, and 42.5% preferred acrylic lens. The posterior capsular tear was the most common complication. CONCLUSION: There are trends toward more cataract surgical procedures performed by a surgeon, increasing preference of topical anesthesia, small incision wound and foldable acrylic lenses which reflected the popularity of phacoemulsification.

[Efficacy of pediatric cataract extraction with intraocular lens implantation]. / Avaliação da eficácia da facectomia com implante de lente intra-ocular na infância.

PURPOSE: To evaluate the efficacy of the use of intraocular lenses in the treatment of pediatric aphakia, according to postoperative visual acuity and refraction change. METHODS: A total of 33 eyes in 27 children were studied. Children with either unilateral or bilateral cataracts were submitted to lensectomy surgery via pars plana, with intraocular lens implant, associated with primary posterior capsulectomy and anterior vitrectomy. The intraocular lenses were calculated for emmetropia in the first postoperative month. All children were less than six years old at the time of the surgery and had a 2.9 year average follow-up. They were divided into 3 groups. Group I (10 eyes), children with unilateral cataracts and under three years old at the time of the surgery; group II (11 eyes), children with unilateral cataracts and above three years old; group III (12 eyes), children with bilateral cataracts and above three years old at the time of the surgery. RESULTS: On the last follow-up examination recorded visual acuity was equal to or above 20/40 in 85% of the eyes. A spherical equivalent close to emmetropia in the first postoperative month was obtained in 70% of the children of group III but only in 30% of group I. Regarding postoperative refraction variation, myopic shift was detected in 81.81% of the cases. The younger the children were when undergoing surgery, the greater the refractional alteration. CONCLUSION: Despite the myopic shift that happens with the use of intraocular lenses in the treatment of pediatric aphakia in children under six years old, the visual result is very good and the residual refraction correction is easily performed. A more prolonged postoperative follow-up would be necessary for long-term evaluation of the results.

[Accuracy of the SRK II, SRK/T, Holladay and Hoffer Q IOL power calculation formulas in hyperopic patients after phacoemulsification]. / Porównanie dokladnosci kalkulacji mocy soczewki wewnatrzgalkowej metodami SRK II, SRK/T, Holladay i Hoffer Q u pacjentów z nadwzrocznoscia, operowanych metoda fakoemulsyfikacji.

PURPOSE: Comparison of the SRK II, SRK/T, Holladay and Hoffer Q formulas accuracy, in calculating IOL power in hyperopic patients. MATERIAL AND METHODS: 34 eyes of 22 hyperopic patients, 15 women and 7 men, at the age from 19 to 85 years old, after phacoemulsification with PCIOL implantation, operated between 1998 and 2004 were analysed retrospectively. The power of IOL was calculated using the SRK/T formula and ranged from 28.5 to 35.0 D. The axial length ranged from 19.6 mm to 21.99 mm. The obtained refraction was measured with autorefractometer from 9 days to 37 month after operation, mean 6 month. In addition, the theoretical target refraction for the implanted IOL was calculated using the SRK II, Holladay and Hoffer Q formulas and the differences between the target and obtained refraction for all the formulas were compared. RESULTS: The best accuracy of IOL power calculation was obtained with the Hoffer Q formula. The Holladay, SRK/T and SRK II formulas gave worse results respectively. CONCLUSIONS: For the purpose of IOL power calculation in hyperopic patients the Hoffer Q or Holladay formula should be chosen from those mentioned above. Nevertheless, miscalculation exceeding 3D also happens in case of using them. The use of SRK II and SRK/T is not recommended. To improve the results other formulas utilising precise measurements of the anterior segment should be applied. If it is impossible then attention should be paid to improving traditional biometry measurements.

Audit of outcome of an extracapsular cataract extraction and posterior chamber intraocular lens training course.

BACKGROUND: A training course for cataract surgery with intraocular lens implantation was organised in April 1997 at the National Eye Centre, Kaduna, Nigeria. Operations were performed by six Nigerian consultant ophthalmologists under the supervision of two surgeons from Aravind Eye Hospital, India. METHODS: A total of 175 eyes with uncomplicated cataracts were operated on after careful selection. All but six patients had extracapsular cataract extraction with posterior chamber intraocular lens insertion during the training programme. RESULTS: The mean age of the patients at operation was 54. 2 years. One hundred and forty five of the operated eyes (85.8%) were blind before surgery of which six (3.6%) remained blind postoperatively. An uncorrected visual acuity of 6/60 or better was achieved in 87.3% eyes after surgery. Forty one patients (24.3%) were blind before surgery, two of whom (1.2%) remained blind afterwards. The most common intraoperative complication was posterior capsular rent which occurred in 10 eyes (5.7%); striate keratopathy/corneal oedema and cortical remnant were the most common immediate postoperative complications, occurring in 44.6% and 8.0%, respectively. CONCLUSION: With adequate surgical skills, extracapsular cataract extraction with posterior chamber intraocular lens implantation offers good visual rehabilitation even under training conditions.

Measurement of axial length of eyes with incomplete filling of silicone oil in the vitreous cavity using x ray computed tomography.

AIMS: To establish a reliable method for measuring the axial length of the eye with incomplete filling of silicone oil in the vitreous cavity in order to determine the IOL power before executing combined cataract surgery and silicone oil removal. METHODS: 12 eyes of 12 patients undergoing combined cataract extraction and silicone oil removal between October 1998 and June 2000 were entered prospectively into this study. All eyes were examined using an x ray computed tomography (CT) scanner. Each axial length of a silicone oil injected eye was measured on the best CT slice among eyeball cuts, which showed both the insertions of the medial and lateral rectus muscle, the thickest slice of the lens, and the optic nerve. The IOL power for the eyes was determined using the SRK/T formula based on the CT data. The deviation of postoperative refraction from the goal refraction was evaluated for each eye. RESULTS: The CT slices demonstrated that the vitreous cavity was not completely filled with the oil in all of the silicone oil injected eyes. The deviation of postoperative refraction from the goal refraction was less than 1 dioptre (D) error in six of 12 eyes (50%), and was less than 2 D error in nine eyes (75%). In the other three eyes having more than 2 D error, the axial length was 27 mm or more. CONCLUSION: The CT measurement of axial eye length for determining IOL might be a useful method for evaluating silicone oil injected eyes before combined cataract surgery and silicone oil removal.

Determinants of patient satisfaction after cataract surgery in 3 settings.

PURPOSE: To analyze the determinants of satisfaction and postoperative visual function after cataract surgery in 3 settings in The Netherlands. SETTING: University Hospital Maastricht (outpatient care), Atrium Medical Center Heerlen (inpatient care), and Medical Center Maastricht Annadal (outpatient care), Maastricht, The Netherlands. METHODS: This cross-sectional study consisted of 150 patients of 50 years and older who had first-eye phacoemulsification with intraocular lens implantation. Data were collected by a written questionnaire. The following parameters were measured: medical outcome, postoperative function, patient satisfaction with medical outcome and hospital care, and overall patient satisfaction. RESULTS: In general, patients were very satisfied (mean score 8.43 on a 10-point scale ranging from 1 = very bad to 10 = excellent). The 3 centers did not differ regarding the patient satisfaction (P =.092). However, postoperative visual function (P =.012), counseling (P =.010), and waiting time (P <.001) were different among the settings. Patient satisfaction with hospital care had a stronger correlation with overall satisfaction than patient satisfaction with the medical outcome (r = 0.669 versus r = 0.543, respectively). CONCLUSIONS: A causal model of patient satisfaction was tested, indicating that satisfaction was related to the patient's preoperative expectations and the quality of care given during the hospital stay and follow-up at the outpatient clinic. This emphasizes the relevance of patient education (to set realistic expectations) and counseling (need for care) by hospital staff in a cataract surgery setting.