Constructing Item Banks for Measuring Quality of Life in Refractive Error.

SIGNIFICANCE: Existing patient-reported outcome instruments in refractive error are paper-based questionnaires. They are not comprehensive and psychometrically robust. This study has identified the content of the refractive error-specific item banks that aim to provide comprehensive and scientific measurement of refractive error-specific quality of life. PURPOSE: The purpose of this study was to identify minimally representative, optimally informative, and efficient sets of items for measuring quality of life in people with refractive error. METHODS: First, items were identified from existing patient-reported outcome instruments. Second, items were developed from qualitative studies with people with refractive error (48 and 101 in-depth interviews in Australia and Nepal, respectively). Third, classification and selection of items were done based on a set of systematic criteria using an iterative process of binning and winnowing. The resulting items underwent cognitive testing with people with refractive error in Australia and in Nepal. Each step was guided by an expert panel consensus. RESULTS: We retrieved 792 items from the existing patient-reported outcome instruments. From the interviews conducted in Australia, a total of 2367 comments were coded into 807 initial items. Similarly, from the interviews conducted in Nepal, 3477 comments were coded into 914 initial items. After binning and winnowing, followed by cognitive testing, a final set of items comprising 337 items for the Item-pool (Australia) and 308 items for the Item-pool (Nepal), both spanning 12 domains, was obtained. Forty-seven percent of items were common across the two item pools. In the Item-pool (Nepal), 65% items were common for corrected and uncorrected refractive error. CONCLUSIONS: We identified the content of two different sets of item banks to comprehensively measure the impact of refractive error on quality of life for people in Australia and Nepal, which may be applicable to high-income country settings and low- and middle-income country settings, respectively. Future work aims to develop computer-adaptive testing system to administer the item banks, resulting in useful measurement tools for researchers, clinicians, and policy planners.

Small Incision Lenticule Extraction (SMILE) for Hyperopia: 12-Month Refractive and Visual Outcomes.

PURPOSE: To evaluate visual and refractive outcomes of small incision lenticule extraction (SMILE) for hyperopia. METHODS: This was a prospective study of vertex-centered hyperopic SMILE using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D). Lenticule parameters were 6.3- to 6.7-mm diameter, 2-mm transition zone, 30-µm minimum thickness, and 120-µm cap thickness. A standard outcomes and stability analysis was performed for the 12-month data, including contrast sensitivity using the Functional Vision Analyzer. RESULTS: For the 93 eyes treated, last follow-up was 12 months for 72 eyes (77%) and 3 months for 11 eyes (12%), with 10 eyes (11%) lost to follow-up. Attempted spherical equivalent refraction (SEQ) was +5.61 ± 1.21 D (range: +1.00 to +6.90 D) and cylinder was -1.01 ± 0.64 D (range: 0.00 to -3.50 D). For eyes targeted for emmetropia (n = 37), uncorrected distance visual acuity was 20/40 or better in 95% of eyes. SEQ relative to target was -0.17 ± 0.85 D (range: -2.20 to +3.00 D) at 3 months and -0.19 ± 0.90 D (range: -2.07 to +3.50 D) at 12 months with 53% within ±0.50 D. For 70 eyes with data at 3 and 12 months, the mean change in SEQ was -0.06 ± 0.53 D (range: -2.00 to +1.75 D) and the mean change in keratometry was -0.22 ± 0.48 D (range: -1.00 to +1.00 D). There was one line loss of corrected distance visual acuity (CDVA) in 16% of eyes and no loss of two or more lines. There was no clinically significant change in contrast sensitivity. CONCLUSIONS: Refractive and visual outcomes 12 months after SMILE for hyperopia were promising, given the high degree of hyperopia corrected and relatively reduced CDVA in this population. There was good refractive and topographic stability between 3 and 12 months. [J Refract Surg. 2019;35(7):442-450.].

Femtosecond Laser-Assisted Small Incision Sutureless Intrastromal Lamellar Keratoplasty (SILK) for Corneal Transplantation in Keratoconus.

PURPOSE: To describe a femtosecond laser-assisted small incision sutureless intrastromal lamellar keratoplasty in an eye with severe keratoconus and report on the outcome with a 1-year follow-up. METHODS: A 20-year-old man with a history of keratoconus presented for evaluation at the Tilganga Institute of Ophthalmology, Kathmandu, Nepal. The patient had previously undergone a deep anterior lamellar keratoplasty in the left eye. Examination of the right eye revealed an uncorrected distance visual acuity (UDVA) of counting fingers with a manifest refraction of -5.00 -3.50 × 170, giving a corrected distance visual acuity (CDVA) of 20/80. Thinnest pachymetry was 425 µm and progression of both anterior and posterior corneal elevation tomography and maximum keratometry was noted compared to examination 2 years prior. The VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) was used to prepare the donor and recipient cornea. The donor graft was inserted into the recipient through the 3-mm small incision. No sutures were applied. RESULTS: At 2 weeks postoperatively, UDVA was 20/50 with a manifest refraction of -1.00 -5.00 × 145 (20/32). One year postoperatively, UDVA was 20/80 with a manifest refraction of -2.50 -3.50 × 125 (20/40-2), with the maximum keratometry decreasing from 64.08 to 56.74 diopters. CONCLUSIONS: This femtosecond laser-assisted sutureless intrastromal corneal transplantation technique may provide an option to improve the quality of vision for some patients with keratoconus, affording a simpler postoperative follow-up course compared to traditional anterior lamellar or full-thickness corneal transplantation. [J Refract Surg. 2019;35(10):663-671.].

Small Incision Lenticule Extraction for Hyperopia: 3-Month Refractive and Visual Outcomes.

PURPOSE: To evaluate visual and refractive outcomes of small incision lenticule extraction (SMILE) for hyperopia. METHODS: This prospective study of vertex-centered hyperopic SMILE used the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and corrected distance visual acuity (CDVA) of 20/40 or better. Lenticule parameters were 6.3- to 6.7-mm diameter, 2-mm transition zone, 30-µm minimum thickness, and 120-µm cap thickness. Standard outcomes analysis was performed for the 3-month data, including contrast sensitivity using the Functional Vision Analyzer. RESULTS: For 93 eyes treated, 3-month data were available for 82 (88%). Attempted spherical equivalent refraction was +5.62 ± 1.20 D (range: +1.00 to +6.90 D) and cylinder was -0.91 ± 0.68 D (range: 0.00 to -3.50 D). For eyes targeted for emmetropia (n = 36), uncorrected distance visual acuity was 20/40 or better in 89%. Spherical equivalent refraction relative to target was -0.17 ± 0.85 D (range: -2.20 to +3.00 D), with 59% within ±0.50 D and 76% within ±1.00 D. There was one line loss of CDVA in 17% of eyes, and one eye lost three lines (1.2%) but recovered to one line lost at 9 months. There was no clinically significant change in contrast sensitivity. CONCLUSIONS: Refractive and visual outcomes 3 months after SMILE for hyperopia were promising, given the high degree of hyperopia corrected and relatively reduced CDVA in this population. Undercorrection of more than 1.00 D in 5 eyes might be partly explained by latent hyperopia in these young patients. [J Refract Surg. 2019;35(1):24-30.].

Uncorrected and corrected refractive error experiences of Nepalese adults: a qualitative study.

PURPOSE: The aim of this study was to explore the impact of corrected and uncorrected refractive error (URE) on Nepalese people's quality of life (QoL), and to compare the QoL status between refractive error subgroups. METHODS: Participants were recruited from Tilganga Institute of Ophthalmology and Dhulikhel Hospital, Nepal. Semi-structured in-depth interviews were conducted with 101 people with refractive error. Thematic analysis was used with matrices produced to compare the occurrence of themes and categories across participants. Themes were identified using an inductive approach. RESULTS: Seven major themes emerged that determined refractive error-specific QoL: activity limitation, inconvenience, health concerns, psycho-social impact, economic impact, general and ocular comfort symptoms, and visual symptoms. Activity limitation, economic impact, and symptoms were the most important themes for the participants with URE, whereas inconvenience associated with wearing glasses was the most important issue in glasses wearers. Similarly, possibilities of having side effects or complications were the major concerns for participants wearing contact lens. In general, refractive surgery addressed socio-emotional impact of wearing glasses or contact lens. However, the surgery participants had concerns such as possibility of having to wear glasses again due to relapse of refractive error. CONCLUSION: Impact of refractive error on people's QoL is multifaceted. Significance of the identified themes varies by refractive error subgroups. Refractive correction may not always address QoL impact of URE but often add unique QoL issues. This study findings also provide content for developing an item-bank for quantitatively measuring refractive error-specific QoL in developing country setting.

Small Incision Lenticule Extraction (SMILE) for Hyperopia: Optical Zone Centration.

PURPOSE: To evaluate optical zone centration of hyperopic small incision lenticule extraction (SMILE). METHODS: This prospective study of 60 consecutive hyperopic SMILE procedures used the VisuMax femtosecond laser and matched LASIK procedures with the VisuMax and MEL 80 excimer lasers (Carl Zeiss Meditec AG, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and astigmatism up to 6.00 D. For SMILE, the optical zone was between 6.3 and 6.7 mm, with a 2-mm transition zone. Two LASIK control groups (6.5- and 7-mm optical zone) were generated matched for spherical equivalent treated. In SMILE, the corneal vertex of the coaxially fixating eye was aligned with the vertex of the curved contact glass. In LASIK, the treatment was centered on the coaxially sighted corneal light reflex (first Purkinje image) with the contralateral eye (Seiler method). A tangential (instantaneous) curvature preoperative to 3 months postoperative difference map was generated for each eye. A fixed grid and set of concentric circles were superimposed on the difference map to measure the offset between the optical zone center and corneal vertex (0,0), and vector analysis was used for comparative analysis. RESULTS: Mean attempted spherical equivalent was +5.61 ± 0.96 D (range: +3.20 to +6.50 D) and mean cylinder was -0.96 ± 0.62 D (range: 0.00 to -2.75 D) in the SMILE group. Mean age was 29 ± 7 years (range: 19 to 52 years) in the SMILE group. Mean centration offset was 0.23 ± 0.15 mm (range: 0 to 0.61 mm) for the SMILE group, 0.33 ± 0.14 mm (range: 0.14 to 0.85 mm) for the 6.5-mm LASIK group, and 0.31 ± 0.19 mm (range: 0.05 to 0.85 mm) for the 7-mm LASIK group. The mean centration offset for SMILE was less than that of both LASIK groups (P < .05). CONCLUSIONS: Optical zone centration of hyperopic SMILE was found to be similar to eye-tracker-centered hyperopic LASIK with the MEL 80 laser. [J Refract Surg. 2017;33(3):150-156.].

Small Incision Lenticule Extraction (SMILE) for Hyperopia: Optical Zone Diameter and Spherical Aberration Induction.

PURPOSE: To evaluate optical zone diameter efficacy and spherical aberration change in hyperopic small incision lenticule extraction (SMILE). METHODS: Prospective study of 60 consecutive hyperopic SMILE procedures using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) and matched LASIK procedures with the VisuMax and MEL 80 excimer (Carl Zeiss Meditec) lasers. Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D). For SMILE, the transition zone was 2 mm and the mean optical programmed zone was 6.37 mm (range: 6.3 to 6.7 mm). Two LASIK control groups (6.5- and 7-mm optical zone) matched for spherical equivalent treated were generated. Both tangential and axial curvature difference maps were generated for each eye at 3 months. A fixed grid and set of concentric circles were superimposed on the difference map to measure the achieved optical zone diameter. RESULTS: Mean attempted spherical equivalent refraction was +5.58 ± 0.95 D (range: +3.20 to +6.50 D) in the SMILE group. By tangential mapping, SMILE programmed at a mean optical zone of 6.37 mm achieved a diameter of 5.03 ± 0.30 mm, similar to 7-mm LASIK (4.96 ± 0.25 mm, P = 0.33) but larger than 6.5-mm LASIK (4.53 ± 0.25 mm, P < .001). By axial mapping, the achieved optical zone diameter was 6.75 ± 0.31 mm for 6.37-mm SMILE, larger than for both 6.5-mm (6.61 ± 0.21 mm) and 7-mm (6.92 ± 0.14 mm) LASIK (P < .01). Spherical aberration changed on average by -0.45 ± 0.22 µm for 6.37-mm SMILE, similar to 7-mm LASIK (-0.50 ± 0.21 µm, P = .29) and less than for 6.5-mm LASIK (-0.69 ± 0.22 µm, P < .001). CONCLUSIONS: The mean achieved optical zone diameter of hyperopic SMILE was found to be larger than the mean achieved optical zone diameter of hyperopic LASIK. Consequently, spherical aberration induction was similar for 6.37-mm SMILE and 7-mm LASIK. [J Refract Surg. 2017;33(6):370-376.].

Contact lenses for visual rehabilitation in Bilateral Nanophthalmos with Retinal Dystrophy- A case report.

BACKGROUND: Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye with short axial length, high hyperopia and high lens to eye volume ratio due to arrested development of the globe in all directions. Different types of fundus changes can rarely occur with nanophthalmos. OBSERVATIONS: This is a case report of a 17 years old female who presented with bilateral gradual progressive visual loss and photophobia at Tilganga Institute of Ophthalmology on 3rd July 2015. Her best corrected visual acuity was 20/300 with +12.00Ds/-1.00Dcyl@180 in the right eye and 20/200 with +12.00Ds/-1.50Dcyl@180 in the left eye. Axial lengths of two eyes were markedly shortened with pigmentary changes at the macula and dull foveal reflex along with retinal flecks in the mid-periphery. Full field ERG showed diminished rod and cone waves suggestive of rod and cone dysfunction. With the use of Rigid Gas Permeable (RGP) contact lenses, the acuity improved to 20/200 and 20/125 in the right and left eye respectively. CONCLUSION: This study proposes the use of contact lenses and light absorptive filters for better visual rehabilitation.

Quality control outcomes analysis of small-incision lenticule extraction for myopia by a novice surgeon at the first refractive surgery unit in Nepal during the first 2 years of operation.

PURPOSE: To evaluate the outcomes of small-incision lenticule extraction for myopia using the Visumax femtosecond laser at the first refractive surgery unit in Nepal during the first 30 months of operation. SETTING: Tilganga Institute of Ophthalmology, Kathmandu, Nepal. DESIGN: Retrospective noncomparative case series. METHODS: Consecutive myopic small-incision lenticule extraction procedures by a fellowship-trained surgeon were evaluated. Inclusion criteria were a preoperative spherical equivalent (SE) refraction up to -10.00 diopters (D) and corrected distance visual acuity (CDVA) of 20/20 or better. Outcomes analysis using the Standard Graphs for Reporting Refractive Surgery was performed over a 3-month follow-up. RESULTS: Three-month data were available for 1396 eyes. The mean attempted SE was -5.78 D ± 1.81 (SD) (range -0.96 to -10.00 D) and the mean cylinder, 0.79 ± 0.69 D (range 0.00 to 5.25 D). Postoperatively, the mean SE relative to target was -0.28 ± 0.29 D (range -1.31 to +1.50 D) and was within ± 0.50 D in 80% of eyes and ± 1.00 D in 99% of eyes. The uncorrected distance visual acuity was 20/20 or better in 95% of eyes and 20/25 or better in 99% of eyes. One line of CDVA was lost in 2% of eyes; no eye lost 2 or more lines. There was a small improvement in contrast sensitivity (P < .01). CONCLUSIONS: The outcomes of myopic small-incision lenticule extraction up to -10.00 D performed at the first refractive surgery unit in Nepal by a fellowship-trained surgeon with no corneal refractive surgery experience were as safe and effective as outcomes in previous studies. FINANCIAL DISCLOSURE: Dr. Reinstein is a consultant to Carl Zeiss Meditec AG and has a proprietary interest in the Artemis technology (Arcscan, Inc.) through patents administered by the Center for Technology Licensing at Cornell University, Ithaca, New York, USA. Drs. Pradhan and Carp have travel expenses to conferences paid by Carl Zeiss Meditec AG. No other author has a financial or proprietary interest in any material or method mentioned.