Contact Lens Spectrum Supplements

Special Edition 2017

Contact Lens Spectrum

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c l s p e c t r u m . c o m C O N T A C T L E N S S P E C T R U M S P E C I A L E D I T I O N 2 0 1 7 71 An important area to view when evaluating a scleral lens fit is the transition over the limbus; the goal is to prevent any touch and to en- sure a smooth landing on the sclera. An inadequate fit at this critical area may induce problems such as con- junctival prolapse and conjunctival debris that will cause fogging. We have been successfully dealing with fogging by designing a smoother transition over the limbus and onto the sclera. Conclusion Customization in scleral lens fit- ting is a healthy direction to pursue. It is possible to adequately define the necessary lens modifications by observation and by using a good trial lens set from a manufacturer that will work with you on the spe- cific changes required to achieve an optimal fit. While not essential, it is important in scleral lens fitting to always try to extend the limits of what you can achieve. CLS For references, please visit www. and click on document #SE2017. CONT ACT LENS CASE REPOR TS Luciano Bastos is the director and clinical in- structor of specialty contact lenses at the In- stituto de Olhos Dr. Saul Bastos (IOSB) and is the director and specialty lens consultant of Ultralentes, a small laboratory specializ- ing in GP and scleral lens designs in Porto Alegre, RS, Brazil. –5.00D power, overall diameter (OAD) 19.4 mm, optic zone (OZ) 14.0 mm, sag 6.144 mm and OS 42.50D base curve, –4.25D power, OAD 19.4 mm, OZ 14.0 mm, sag 6.144 mm. Discussion Scleral lens fitting has the benefit of being forgiving for different el- evations and areas of the cornea. In some cases, there will inevitably be some areas in which the posterior surface of the lens is better aligned to the corneal surface compared to others. We always look for possible fit improvements when a patient comes for a refit, even if the fitting was adequate, the patient is satis- fied, and visual acuity is good. The best time to evaluate a scler- al lens fitting is always after 3 to 4 hours of lens wear, as by that time the lens has already settled and will not change significantly. We also prefer to instill fluorescein after the lens is settled to observe whether the channels are working. Ten to 15 minutes is usually enough to observe the fluorescein entering the liquid lens reservoir; in 1 hour, the overall fluid in the vault will be mixed with the contrast. Figure 2. (A) Scheimpflug imaging OD; (B) Scheimpflug imaging OS. B A Figure 3. (A) Slit lamp cross-section view OD; (B) Slit lamp cross-section view OS. Figure 4. (A) Front view of scleral lens design; (B) Scleral lens OS. A A B B

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