Part V of Apps for the Ophthalmologist will focus on interesting calculator apps that prove to be helpful in different disciplines of eye care, including glasses refractions, contact lens dispensing, glaucoma risk factoring, etc.
Calculator Apps
Eye Pro 2013 ($69.99)
By EB Eye Limited
This is the new version 1.2 of Eye Pro for the iPad, iTouch and iPhone which was updated in February of 2015. It is an advanced ophthalmological calculator used for standard biometry, phaco group analysis, biometry post laser refractive surgery, SIA calculations for single or group cases, astigmatism correction reduction calculations, and toric IOL calculations. It also serves as a visual acuity converter, a corneal-spectacle plane converter, a Cartesian-Polar notation converter, and provides optical formulas. Details of each of the calculators can be found on iTunes, and the app requires iOS 6.0 or later.
Optics Clinical Calculator ($4.99)
By Evan Schoenberg
This app can be helpful for general or refractive ophthalmologists, residents, optometrists and opticians. The app offers streamlined access to calculators used in prescribing lenses and understanding optics. Results are provided right away and thorough explanations of formulas with applications and clinical notes can be found on the app as well. Calculators include base curve, convergence, diopter to/from radius (mm) conversion, diopters from focal distance, intermediate and near vision prescriptions from standard refraction, lens power in oblique meridians, oblique crossed cylinders, ocular curve, optical center decentration, slab-off calculator (induced prism), and vertex distance. Users get free upgrades for life, including additional requested calculators. It was last updated in January 2014, is 2.7 MB and requires iOS 6.0 or later. It is compatible with iPhone, iPad and iPod Touch. The reviews have been very promising, noting a simple interface and no negatives.
Opticalc Contact Lens Calculator ($3.99)
By Optical Directions Consulting
Opticalc Toric Contact Lens Calculator helps in prescribing soft contact lenses. Ocular refraction corrected for vertex distance can be determined when a patient’s refraction and vertex distance is provided. The system then provides a recommended spherical contact lens power based on the patient’s spherocylindrical refraction. If a toric lens is not properly fitting, this app will calculate how much the lens fit is off by and suggest a new lens to order. With the patient’s contact lens power and the spectacle over-correction, Opticalc will tell you how much the lens is rotating and recommend the correct lens power to order. The app has a ‘freeform script entry’ so that if you enter ‘50’ it will automatically convert to ‘+0.50’. Cylinder powers are assumed to be minus. However, it does not convert to plus cylinder. The latest version, 1.8, updated in May 2014, has a fixed calculation bug, vertex distance is remembered properly and it is updated for iOS 7. It is 0.3 MB in size. Reviews state that this app is great for getting a starting point on a new contact lens fit. Also, the developer is apparently very easy to contact and responsive to questions in a timely manner.
Glaucoma Calc ($1.99)
By Optical Directions Consulting
This app can be used to estimate the risk of a patient with ocular hypertension developing glaucoma within 5 years. Glaucoma Calc uses the same calculation data as some other online calculators and electronic single-purpose calculators, but is accessible on your mobile device. It supports Humphrey, Medmont and Octopus without the need for manual conversion. One enters 5 parameters: age, IOP, C/D ratio, CCT and PSD/PD/LV in order to assess risk. The application remembers its state even if it is shut down, so data is not lost if outside range or if a call comes through. Parameters for each eye may be entered individually. The latest version is 1.6, updated in 2012, and it is 0.2 MB in size. Reviewers state this app is very easy to use and a great additional tool for a glaucoma evaluation.
Eye Calculator ($0.99)
By Manuel Rodriguez Vallejo
This app provides vision science calculations for a variety of functions, including distometry with contact lenses, diopters to micras for Defocus aberration, computing final toric contact lens after over-refraction and considering contact lens rotation, prismatic effect induced by a toric lens decentration, conversion between visual acuity logMAR notation and decimal notation, and conversion between visual acuity Snellen and decimal. This app supports English and Spanish languages, among many others. Version 1.0.2 was updated in December 2014, and it is 12.3 MB in size.
AstigMaster ($9.99)
By EB Eye Limited
AstigMaster is a surgically induced astigmatism (SIA) vector calculator for the iPhone. This app works with either refractions or K values, displays the results either at the spectacle or corneal plane and performs automatic conversions to Cartesian (X;Y) notation for statistical analysis. These features are available on Eye Pro 2013, listed above, which also includes a phaco outcomes calculator, a toric IOL calculator, biometry after refractive surgery, standard biometry (SRK/T, Hoffer Q), visual acuity converter, refraction converter, Cartesian/polar notation converter and optical formulas. This app was updated on January 26, 2015, the latest version is 1.7, it requires iOS 6.o or later and is compatible with the iPhone (optimized for the iPhone 5), iPad and iPod touch. The size is 12.9 MB. New in the latest version are general graphic and performance improvements for iOS 8, as well as bug fixes.
CL Calcs ($4.99)
By Todd Zarwell
This app is similar to the EyeDock app, which requires a membership to www.eyedock.com. The app is a vertexing calculator that converts from a spectacle Rx to the corneal plane. It will accept and return results in plus or minus cylinder and allows for different vertex distances. The app includes vertexing and keratometry conversion tables, oblique cross cylinder calculator for calculating new toric lenses based on lens rotation and overrefraction. It has a keratometry conversion calculator that converts mm to diopters and vice versa. A wide range of curvatures can be entered, allowing flat post-surgical and steep ectasia corneas to be converted. Another feature is the contact lens design, including spherical and toric soft lenses, as well as spherical, bitoric, front toric and back toric RGPs. One can get contact lens design advice with pros and cons of different lens options. There are custom onscreen keypads for all calculators that only needed numbers and symbols, making entering refractions, CL powers and keratometry values fast. The latest version, updated in Oct 2014, is 1.11, 3.4 MB and requires iOS 7.0 or later. This app is compatible with iPhone (optimized for iPhone 5), iPad and iPod touch.
The above apps are exciting additions to an eye care specialist’s armamentarium. Not only do they offer help in different aspects of eye calculations, but they can be used remotely, another added bonus to our world of technology.