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CORNEAL TRANSPLANT

The Use of Scleral Rigid Gas Permeable Contact Lenses in Keratoconus – A Case Report

A special thank you to Judy Tran for developing this amazing case report.

Introduction:

The prevalence of keratoconus (KCN) in the United States is approximately 8.8-229 per 100,000 affecting both men and women equally.1 KCN is a progressive disease resulting in ectasia of the corneal stroma. It is a noninflammatory process that causes a decrease in patient visual acuity (VA) from the changes in corneal shape that leads to an increase in myopia and irregular astigmatism. What causes KCN is still not completely understood but there are studies that show a correlation between the disease and environmental factors such as eye rubbing, a family history of the disease, and atopy. Age, ethnicity, contact lens use, as well as exposure to sunlight are also observed environmental risk factors for KCN. Genetically, there has been some evidence of genes VXX1 and SOD1 being highly associated with the pathogenesis of the condition which is autosomal dominant but can occur in a sporadic pattern.2

There is currently no cure for KCN, however corneal collagen cross-linking (CXL) has been shown to have promising results in slowing the progression of the disease especially in cases involving severe progressive KCN. CXL utilizes riboflavin and a photo-oxidative reaction to increase corneal stiffness by altering the collagen within the corneal tissue. The changes to the collagen consist of increasing the number of covalent bonds and increasing the resistance to enzymatic degradation.3 CXL has been widely used in many countries for managing KCN, but it was only just recently FDA approved in the United States April 2016 and this method of treatment is becoming increasingly popular since its approval. Before the development of CXL, a corneal transplant was the only treatment for KCN but is indicated only when the disease had progressed into more advanced stages. Even after a corneal transplant, patients are still at risk for developing KCN again in the transplanted cornea. Another major complication post corneal transplant is glaucoma. There is a significant risk for the development of glaucoma after a corneal transplant as seen in a study conducted by Zheng et al.4 Depending on the severity of glaucoma, treatment could be lifetime eye drops or even requiring another ocular surgery. Just like KCN, glaucoma is an uncurable condition that can lead to blindness. Even though CXL and corneal transplant are both FDA approved methods for treating KCN, they do not always help with the major side effect of the disease which is reduced vision.

Due to the optics of an irregular cornea often seen in KCN, spectacles often cannot correct the vision. Specialty contact lenses are typically used to help maximize vision. Usually, a corneal rigid gas permeable contact lenses (RGPCL) are often indicated initially but with recent advancements, scleral rigid gas permeable contact lenses (ScCL) have shown to be an excellent, safe, and effective alternative.5 Since the scleral contact lenses do not interact with the cornea, there is a therapeutic benefit to using the larger lens especially in patients with severe dry eye. There is a liquid layer between the ScCL and the cornea which can provide constant hydration to the corneal cells. ScCL are often reserved for more severe KCN but with their material and fitting advancements, it should be an option at any stage of the condition to help patients achieve their best potential VA as well as to delay the possible need for a corneal transplant.6 This case report supports the benefits of using a ScCL for a patient with a moderate and severe KCN. By using a more custom fitted ScCL, the patient was able to reach a VA of 20/20 with optimal comfort and the ScCL could potentially reduce their need for a corneal transplant later in life.

Case description:

Visit 1: The consultation. Patient DB, a 51-year-old Hispanic male, was referred to the Contact Lens Institute of Nevada after completing a comprehensive eye exam at a Sam’s Club Optical in May 2021. The referring optometrist diagnosed the patient with myopia, astigmatism, and bilateral keratoconus with the right eye being more severe than the left. There was no spectacle prescription recommended at this time due to the severity of the KCN. The patient was advised that a specialty contact lens would provide better vision than glasses.

DB’s medical history was unremarkable, the patient had denied any medical diagnosis, medications, and allergies. The patient was unaware of any KCN prior to the eye examination in May 2021. The patient had also denied any other ocular conditions and surgeries.
Entering unaided VA were OD 20/200 and OS 20/25. Anterior segment evaluation revealed corneal central inferior thinning with striae OU. Corneal thinning and striae were mild in OS and significantly worse in OD. Fluorescein dye evaluation revealed mild SPK staining over the cone apex of OD. There were nasal and temporal pingueculas noted OU. The rest of the anterior segment was unremarkable. Posterior health was evaluated via retinal imaging which was unremarkable. There were no signs of glaucoma, macular degeneration, or any retinal disease that could possibly contribute to the patient’s reduced vision.

A KCN pattern was observed in the topometric exam (Figure 1). An OCT and a scleral mapping (sMAP) were performed over DB’s naked eye (Figure 2). The results of the exam are listed in Table 1. Based on the topography and scleral elevation (Figure 3), a Europa diagnostic lens was selected for both eyes and the parameters of the diagnostic lenses are seen in Table 2. The suggested lenses are based on a sagittal depth (Table 1), the sMAP software determines the sagittal depth assuming a chord length of 16mm and incorporating a 300um buffer. The lenses were allowed to settle for approximately 5 minutes before assessing the vision and fit, as well as an auto-refraction/keratometry over the diagnostic lens (Table 3). The over-refraction (Table 3) was determined with the starting point measured with the auto-refractor.

Figure 1: Using the Medmont, corneal topography reveals a KCN pattern in both OD and OS.

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Figure 2: Images of DB’s naked eye with trace sodium fluorescence that was instilled prior. Photos were taken during the slit-lamp examination with the ION Imaging system.

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Figure 3: sMAP scleral elevation of DB’s OD and OS.

Measurements over naked eye OD OS
Pachymetry (OCT) 405um 491um
Keratometry (Topo) 56.43D @ 160°/ 71.61D 43.21D @ 2°/ 46.38D
Corneal Cylinder (Topo) 15.18D 3.17D
Scleral Toricity (sMAP) 214um 270um
Sagittal Depth 4479um 4456um

Table 1: Measurements taken over DB’s naked eyes.

Diagnostic Lens Parameters OD OS
Base Curve 45.00D 46.00D
Sagittal Depth 4560um 4660um
Power -1.50D -2.00D
Overall Diameter 16.0mm 16.0mm
Optic Zone Diameter 0.2mm 0.2mm
Center Thickness 0.4mm 0.4mm
Material HEXA100 HEXA100

Table 2: The Europa Lens made by Visionary Optics were the diagnostic lenses used.

Lens Assessment OD OS
Central Clearance 58um – over apex 388um
Limbal Clearance Present 360° Present 360°
Lens edges Flat 360° Flat 360°
Impingement or Blanching Negative 360° Negative 360°
Auto-refraction +0.25 -2.50×067 -1.50 -1.50×095
Auto-keratometry 43.50D @ 162°/ 43.75D 43.75D @ 161°/ 44.00D
Over-refraction in Phoropter -0.25 -2.50×080 -1.00 -1.75×095
VA with Over-refraction 20/20-2 20/20

Table 3: Fit and vision assessment of the diagnostic Europa Lens on the patient’s eyes.

Due to the DB’s high scleral toricity and high internal cylinder, a custom impression ScCL was recommended for both eyes to maximally optimize visual acuity and fit but other fitting modalities were also discussed to the patient. The patient had opted for the premium custom fit for their right eye, the eye with more severe KCN and the advanced custom fit for their left eye. The premium custom fit uses an impression of the eye, similar to a dental mold, to design a lens with a 3D scanner and utilizes three million data points from the mold (Figure 4). The advanced custom fit uses the scleral mapping scan of the eye, and that special software is able to design a lens from a million data points. Two impressions of the right eye for the custom EyePrint Prosthetic were completed in-office (Figure 5) and the sMAP images that were taken were sent to the Visionary Optics Lab for the advanced custom ScCL fit for the left eye. All images and the over-refraction were sent to both labs for the lens design.

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Figure 4: Front surface and back surface design of the custom EyePrint Prosthetic ScCL for DB’s right eye.

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Figure 5: A visual of how the eye impression is completed for the EyePrint Prosthetic. Note: the patient in the image is not the patient in the case report.

The patient was expected to return to clinic once the ScCL arrive for a training session before being dispensed.

Visit 2: Training and dispense. An EyePrint Prosthetic ScCL was ordered for the right eye and a Latitude ScCL was ordered for the left; lens design parameters are listed in Table 4. The ScCLs were inserted for DB shortly after their arrival (Figure 6). The lens was allowed to settle for approximately 10 minutes before checking VA (Table 5) and assessing the lenses (Table 6). The clearance was determined with an anterior segment OCT (Figure 7), which was checked at the center and limbus of the cornea. Before the training session, an over-refraction was completed with the auto-refraction as the starting point and VA was measured (Table 5). Throughout the over-refraction, the patient reported fluctuating vision with may have been due to the lens settling which affected the reliability of the over-refraction.

Lens Parameters OD (EyePrint Prosthetic) OS (Latitude Scleral Lens)
Base Curve 8.336mm (40.49D) 7.55mm (44.70D)
Sagittal Depth 5788um 5134um
Power +2.75 – 2.38×080 -1.67 -1.75×095
Overall Diameter 18.0mm 16.5mm
Center Thickness 0.527mm 0.30mm
Material Optimum Extra Optimum Extra

Table 4: Custom ScCLs parameters received by the manufactures.

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Figure 6: DB with custom EyePrint Prosthetic on OD and custom Latitude lens on OS.

Vision Assessment OD OS
Entering VA 20-20 20/50
Auto-refraction +1.50 -1.25×022 +0.25 -1.00×136
Auto-keratometry 40.25 @ 078/ 42.00 41.75 @ 069/ 42.50
Over-refraction in Phoropter +0.50 -1.50×120 +1.25 -1.50×126
VA with Over-refraction 20/25+2 20/20-1

Table 5: Vision assessment through custom ScCL.

Lens Assessment OD OS
Centration Centered Centered
Central Clearance 252um – over apex 396um
Limbal Clearance Acceptable 360° Acceptable 360°
Lens edges Flat 360° Mild nasal edge lift
Movement 0.25mm 0.25mm
Lens Marker Location 6:00 7:00
Impingement or Blanching Negative 360° Negative 360°
Conjunctival Prolapse None 11:00 to 1:00

Table 6: Lens assessment of the custom ScCL on DB’s eyes after 10 minutes of settling.

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Figure 7: Anterior segment OCT reveals central clearance of the ScCL on the eyes. Top photo: OD, bottom photo: OS.

After lens evaluation, DB was educated on how to properly insert and remove the scleral lenses by using a DMV to insert and a small plunger to remove. The patient was taught how to clean and store the ScCLs using Tangible Clean Multipurpose Solution and to use sodium chloride preservative-free saline to fill the lens bowl prior to insertion. DB had no difficulties with removing the lenses with the use of the small plunger. They were advised to stick the plunger inferiorly of the lens rather than directly center, this creates an uneven pressure of release for the lens to come off the scleral resting points. There were some difficulties with insertion, DB has deeper set eyes and larger hands, so they found it difficult to maneuver the lens into the eye when they used one hand to open the upper lid and the other hand to hold the lower lid and DMV plunger with the ScCL. The technique that was most comfortable for DB was using one hand to hold the upper and lower lid while the other hand solely guided the DMV and ScCL. A scleral stand was suggested to patient which would essentially act as a third arm allowing the patient to comfortably hold open the eyelids with both hands as the move towards the scleral stand that props up the DMV and ScCL. DB expressed feeling comfortable with insertion without the need of the scleral stand. DB successfully completed training by removing and inserting the ScCL once leaving the clinic with them on, and DB was scheduled to return to the clinic in a week for a follow-up to recheck their visual acuity and the fit. The patient was advised to wear the lenses as much as possible to allow for adaptation.

Visit 3: 1 week follow-up. Case History: DB had worn the ScCL OU for 4 hours prior to the appointment. Average wear time was about 1 to 2 hours, and this was due to their eyes feeling fatigued during wear. There were difficulties with reading and intermediate distance because their eyes felt like the vision was too overwhelming which caused the eyes to feel tired. DB reports seeing better at intermediate distances without ScCL. With lenses, OD vision is much clearer than OS vision. There was mild discomfort with the OS at the appointment but denies and redness from the ScCL. The patient also noted that there were some difficulties with insertion because they could not get their eyes wide enough, but ScCL removal was easy with the use of the small plunger. The fit of the ScCL was reassessed (Figure 8), clearance was determined with the anterior segment OCT (Table 7 and Figure 9), auto-refraction/keratometry was completed, and an over-refraction was measured with the auto-refraction as a starting point (Table 8).

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Figure 8: 1-week follow-up with custom ScCL with Eyeprint Prosthetic for OD and Latitude Lens for OS.

Vision Assessment OD OS
Entering VA 20/20-1 20/50
Auto-refraction +1.25 -1.00×012 +1.25 -2.75×109
Auto-keratometry 40.25 @ 078/ 41.75 41.50 @ 025/115
Over-refraction in Phoropter +0.25DS +0.75 -1.75×135
VA with Over-refraction 20/20-2 20/20-1

Table 7: Vision assessment through custom ScCL at 1 week follow-up.

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Figure 9: Anterior segment OCT after 4 hours of ScCL wear on the eyes at 1-week follow-up. Top photo: OD, bottom photo: OS.

Lens Assessment OD OS
Centration Centered Centered
Central Clearance 222um 340um
Limbal Clearance Acceptable 360° Acceptable 360°
Lens edges Flat 360° Flat 360°
Movement Minimal Minimal
Lens Marker location 6:00 8:00
Impingement or Blanching Negative 360° Negative 360°

Table 8: Lens assessment of custom ScCL after 4 hours of wear.

Since the patient had difficulties with near and intermediate vision, a monovision fit was discussed to maximize acuity at all distances and to improve patient visual comfort. However, with the monovision fit, it was discussed that distance vision may be reduced to compensate for near vision. It was also educated to the patient that with a monovision fit, depth perception will be reduced. A monovision fit was trial framed and DB could not adapt to the vision. The patient opted to best correct distance vision in the ScCL for part-time wear and was educated that an over-the-counter reading spectacle prescription will be necessary to optimize near vision.

The overall fit of the lenses was acceptable, the only modification needed was to change the prescription of the left eye since the patient entering visual acuity was 20/50. A new lens was ordered to adjust the lens prescription incorporating the over-refraction that was determined (Table 7). The patient will continue with the right lens to allow more time to adapt. Another modification that will be considered at the next dispense appointment is possibly making the OD ScCL a smaller diameter for easier insertion. The patient is to return to the clinic for a new OS latitude ScCL dispense when it arrives.

Discussion:

Before the development of the corneal topographer, the only way to diagnose KCN was through slit lamp observed clinical signs, therefore it was often not diagnosed until later stages. Corneal signs such as corneal protrusion, corneal apex thinning, Vogt’s striae, Fleisher’s ring, and possibly corneal scarring typically represent more advanced stages of the condition. In earlier stages of KCN, patient symptoms can include reduced vision due to an increase in myopia and irregular astigmatism, visual distortions, and light sensitivity. Because of the constant changes in vision, patients with KCN may need to frequently change their spectacle correction. Now that the corneal topographer is becoming increasing popular and more readily available, early stages of KCN can be more easily diagnosed with the technology and treatment such as CXL can be implemented sooner to slow down the disease progression, ultimately preserving the patients’ vision.1 A 10-year study conducted by Raiskup et al. showed that CXL treatment was effective in decreasing the progression of the disease as well as stabilizing the cornea long-term ultimately reducing the need for a corneal transplant. By decreasing the progression of the disease by stabilizing the cornea, vision is preserved. CXL provides treatment in early diagnoses especially in adolescents with less complications compared to a corneal transplant.7 The Nordstorm et al. study demonstrated that after a year post CXL treatment in KCN subjects had decreased corneal irregularities and improved vision. There was also no damage or any cell loss to the corneal endothelium. The study demonstrated that CXL treatment for KCN is not only effective in slowing the progression of the disease, that the procedure is also safe.8

In early stages of the disease, a spectacle correction can provide adequate vision, however as the disease progresses, glasses are unable to mask the irregular astigmatism that typically occurs. Corneal RGPCL are common for correcting keratoconus. However, ScCL are becoming increasing popular because of they provide better patient comfort compared to corneal RGPCL. In a study conducted by Levit, Benwell, and Evans, they found that although there was no significant difference in vision or vision quality of life, KCN patients preferred ScCL over corneal RGPCL because of the significant difference in comfort.9 ScCL are typically preferred over corneal RGP because of their design, they rest only on the sclera which allows the lens to vault over the cornea entirely. This minimizes any interaction between the cornea and the contact lenses. ScCL can also help reduced the need of a corneal transplant in patients with severe keratoconus, which was observed in a study by Koppen et al. A majority of subjects with severe KCN had a decreased need for a corneal transplant when they were successfully fitted with a ScCL. Subjects that underwent a corneal transplant even after a ScCL fit was due to their inability to tolerate the lens.6 By fitting KCN patients with ScCL rather than treating with a corneal transplant, this is reduced the complications associated with the surgical procedure such as glaucoma.

A retrospective study by Fuller and Wang assessed the prevalence of ScCL complications such as microbial keratitis, phlyctenulosis, cornea abrasion, contact lens-induced acute red eye, corneal infiltrates, pingueculitis, and hydrops. The complications were observed to be related to poor wetting, poor handling, reservoir fogging, lens intolerance, deposits in the eye, and broken lenses in the eye. Although the adverse effects occurred in a small percentage of subjects in the study, they can still occur with any ScCL, therefore proper ScCL fitting, and patient education is important to reduce the risk of any complications. Other management options for complications were adding a surface treatment to the lens, replacing the lens, and adjusting the wear time. Overall, the study concluded that ScCL for KCN patients are safe and effective.5

Most traditional ScCLs design assume that the sclera is a uniform, spherical shape, however, this is not the case for many individuals. With the use of a sMap3D corneo-scleral topographer, DeNaeyer et al. measured not only the elevation of the cornea, but the elevation of the sclera as well on 140 eyes. They determined that approximately only 5.7% of the eyes had a spherical scleral shape, 28.6% had a regular toricity, and actually 40.7% had asymmetric elevations and depressions. This means that a majority of the population have a non-spherical scleral yet, most practitioners continue to fit scleral lenses empirically with a traditional lens design. Common complications often seen with ScCLs that have a poor landing on the sclera is conjunctival blanching, conjunctival prolapse and can even potentially result in staining of the surface tissues.10 By determining the patient’s scleral shape at the initial visit, it can help potentially decrease fitting chair time and improve patient comfort with the ScCL.

In the case of DB, their stage of KCN was well advanced, especially in their right eye, therefore their reduced vision of 20/200 could not be corrected with glasses. Scleral lenses were selected over a corneal RGP lens for maximum comfort and optimal visual acuity. A more custom fit ScCL was chosen over a traditional fit because of the patients high scleral toricity that was determined initially at the consultation appointment. A well-fitted ScCL was achieved just after one visit and by using a more custom ScCL design, such as the Latitude and EyePrint Prosthetic ScCL, the patient was able to achieve 20/20 vision in the poorer 20/200 seeing eye while maximizing the lens comfort reducing any risk of ScCL complications. Hopefully, by fitting DB in a ScCL it reduces their need for a corneal transplant later.

Conclusion:

Fitting a ScCL can be intimating and has a poor stigma of being difficult and time consuming, requiring a lot of follow-ups and lens adjustments. However, with advancements in corneal imaging and mapping, diagnosing KCN and fitting ScCL is much simpler with less chair time. By gaining the confidence to fit ScCL, the care and services can be provided to KCN patients without the need for an additional referral. ScCL have been shown to be safe and effective for achieving optimal vision for KCN patients even after a couple of months post CXL treatment. By diagnosing KCN in earlier stages, CXL can be implemented to immediately stabilize the cornea before the disease progresses, then with the added ScCL fit, the potential need for a corneal transplant is significantly reduced along with the associated complications with the surgical procedure.

References:

  1. Leucci, M., & Carter, M. (2018). Clinical signs in keratoconus. Optometry Today (London), 58(11), 86.
  2. Hashemi, H., Heydarian, S., Hooshmand, E., Saatchi, M., Yekta, A., Aghamirsalim, M., Valadkhan, M., Mortazavi, M., Hashemi, A. & Khabazkhoob, M. (2020). The Prevalence and Risk Factors for Keratoconus: A Systematic Review and Meta-Analysis. Cornea, 39 (2), 263-270. doi: 10.1097/ICO.0000000000002150.
  3. Vinciguerra, R., Romano, M. R., Camesasca, F. I., Azzolini, C., Trazza, S., Morenghi, E., & Vinciguerra, P. (2013). Corneal cross-linking as a treatment for keratoconus: Four-year morphologic and clinical outcomes with respect to patient age. Ophthalmology (Rochester, Minn.), 120(5), 908-916. https://doi.org/10.1016/j.ophtha.2012.10.023
  4. Zheng, C., Yu, F., Tseng, V. L., Lum, F., & Coleman, A. L. (2018). Risk of glaucoma surgery after corneal transplant surgery in medicare patients.American Journal of Ophthalmology, 192, 104-112. https://doi.org/10.1016/j.ajo.2018.05.004
  5. Fuller, D. G. & Wang, Y. (2020). Safety and Efficacy of Scleral Lenses for Keratoconus. Optometry and Vision Science, 97 (9), 741-748. doi: 10.1097/OPX.0000000000001578.
  6. Koppen, C., Kreps, E. O., Anthonissen, L., Van Hoey, M., Dhubhghaill, S. N., & Vermeulen, L. (2018). Scleral lenses reduce the need for corneal transplants in severe keratoconus.American Journal of Ophthalmology, 185, 43-47. https://doi.org/10.1016/j.ajo.2017.10.022
  7. Raiskup, Frederik, MD, PhD, FEBO, Theuring, A., MD, Pillunat, L. E., MD, & Spoerl, E., PhD. (2015). Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: Ten-year results.Journal of Cataract and Refractive Surgery, 41(1), 41-46. https://doi.org/10.1016/j.jcrs.2014.09.033
  8. Nordström, M., Schiller, M., Fredriksson, A., & Behndig, A. (2017). Refractive improvements and safety with topography-guided corneal crosslinking for keratoconus: 1-year results.British Journal of Ophthalmology, 101(7), 920-925. https://doi.org/10.1136/bjophthalmol-2016-309210
  9. Levit, A., Benwell, M., & Evans, B. J. W. (2020). Randomised controlled trial of corneal vs. scleral rigid gas permeable contact lenses for keratoconus and other ectatic corneal disorders.Contact Lens & Anterior Eye, 43(6), 543-552. https://doi.org/10.1016/j.clae.2019.12.007
  10. DeNaeyer, G., Sanders, D., van der Worp, E., Jedlicka, J., Michaud, L., & Morrison, S. (2017). Qualitative Assessment of Scleral Shape Patterns Using a New Wide Field Ocular Surface Elevation Topographer: The SSSG Study. Journal of Contact Lens Research and Science, 1(1), 12-22. https://doi.org/10.22374/jclrs.v1i1.11

Dry Eye Patient Fit Into Custom Scleral Lens

Thank you Dr. Wellish for this kind referral.

66 year old Male was referred to us for a scleral lens consultation for dry eyes. This patient had a h/o of PRK (corneal transplants) in both eyes in the 1990’s and had recently undergone cataract surgery in the right eye

He opted for the Multifocal PC IOL for the right eye (so he could see distance and near without glasses) and was interested in doing the same for his left eye. Unfortunately, his signs of dry eyes were too severe to proceed. Dr. Wellish kindly referred him to us to help heal his left eye with a scleral lens. Our goal was to fit him into a scleral lens to help hydrate and protect the cornea, allowing it to heal for possible cataract surgery.

With a diagnostic lens, his vision improved significantly and was suspected that it could be good enough to delay cataract surgery. Due to his high scleral toricity, we recommended a custom scleral lens to maximize the fit and comfort of the lens.

After wearing the Latitude lens for about 3 weeks, he was able to achieve 20/20 in the distance! The Latitude scleral lens is a custom scleral lens that uses 3D imaging to create a custom fit scleral lens. At this point, we incorporated multifocal optics into the left scleral lens to match the multifocal IOL in the right eye. He has been very happy with his vision near and far in both eyes, and sometimes feels that his left eye is more comfortable throughout the day than his right eye! The plan is to continue monitoring his cataract and managing the signs and symptoms of his dry eyes.

OS Scleral Elevation

OS cornea with NaFl 3

OS cornea with NaFl 2

OS cornea

OD topo axial crop

OS topo axial crop

OS inf edge Medmont

OS latitude Medmont

OCT OS temporal

OCT OS nasal

Can Corneal Transplant Patients Wear Scleral Lenses?

Can corneal transplant patients wear scleral lenses?

We had the pleasure of seeing a kindly referred patient for a specialty contact lens consultation yesterday.

This 78 year old white female has a positive ocular history of radial keratotomy (RK) surgery in both eyes in 1990, followed by a corneal transplant in the right eye in 1995, and then had LASIK on top of the right transplant in 1998. Radial keratotomy was a surgery performed in the late 1980’s and early 1990’s to help correct patient’s vision. It has now been replaced with safer options such as LASIK and permanent contact lenses.

Both eyes underwent cataract surgery in 2014.

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Right eye corneal transplant

She complains that her vision is blurry, distorted and double. This is very common for patients who’ve undergone RK surgery. Because of the scalpel cuts into the cornea, this creates an irregular shape, which distorts the image coming into your eye. This results in fuzzy, wavy, fluctuating, blurry vision. She was kindly referred by her corneal specialist, Dr. Casey at Nvision, to our clinic for an evaluation.

With glasses, she can see 20/200 “double” in the right eye and 20/50 “double” in the left eye. The corneal transplant looked clear centrally with minimal neovascularization inferiorly. RK scars were present on both eyes. When I assess a corneal transplant, I make sure that the center of the transplant is clear. If there is major scar tissue or haze within the transplant, there may not be an opportunity for vision improvement. Luckily, for this patient, her corneal transplant is very clear.

OS+rk+scarring+2

Left eye showing radial keratotomy (RK) scarring

When I am not sure if a patient will see better with a specialty lens, I always place a diagnostic lens on the eye. This will help us determine whether or not a specialty contact lens will improve your vision. If we put a diagnostic lens on and perform a few short tests, it will determine the best potential for vision improvement. For instance, let’s say you can only see the 20/400 line at the eye doctor (the big “E”). If we are not sure whether or not your vision will be helped with a contact lens, we will place a diagnostic lens on your eye and re-assess the vision. If your vision improves, it is certainly worth it to move forward with the fitting process.

Before that, we took sMap 3D images of each eye to map the shape of her sclera, the white part of the eye. Then, we placed diagnostic Europa scleral lenses onto the eyes to see what her best vision would be. There was superior touch with the diagnostic lenses on the right eye (see the OCT image), so we knew a traditional scleral lens may not be the best option for her. A more custom lens would be better suited for her unique eye shape.

oct+showing+superior+touch

OCT imaging showing superior touch

With scleral lenses, she could achieve 20/50 in the right eye and 20/40 in the left eye. When a patient doesn’t see better on the visual acuity chart, I always ask them to rate the “quality” of their vision. She stated the letters were much sharper and less distorted. Since the vision improved the overall quality and clarity of her vision, we decided to order the Latitude custom scleral lenses.

We are really hoping to improve her vision with these special lenses!

Thank you Dr. Casey for your kind referral of your patient to our clinic!

 

Contact Lens Options for Corneal Transplant Patients

A very interesting corneal transplant patient arrived today for a consultation.

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You can see the double running suture for this corneal transplant patient

He had a herpes scar years ago, which led him to a corneal transplant in the left eye in 2018. After the transplant healed, he was fit into spectacles to improve his vision. He has always suffered with poor vision after the transplant, but claimed he didn’t know there were any other options.

I am always surprised when patients tell me that they’ve undergone a corneal transplant, but have not tried any contact lens options to correct their vision. When you get a corneal transplant, it creates a very irregular surface. This irregular surface usually requires a specialty contact lens such as a corneal gas permeable lens or a scleral lens to help smooth out the optical surface. By using a special type of contact lens to re-direct the light entering your eye, the result can be a remarkable improvement in vision.

He sought out another opinion from Dr. Wellish, and Dr. Wellish recommended a scleral lens to improve his vision.

He can see 20/200 “double” with best corrected glasses in his left eye. If you’ve been to the eye doctor, you know that the big “E” is the largest letter on the vision chart. The big “E” represents 20/400 vision, which is very poor vision. As the numbers on the vision chart get smaller, the better your vision is. Hence the term “20/20.” Someone with 20/20 vision has perfect vision. In this patient’s case, 20/200 is also very poor vision.

The transplant has a double running suture, which is what you see in the photo. This technique provides the benefits of a single continuous running suture with the added safety and security of a second continuous running suture. Corneal transplant patients run the risk of hypoxia, and not getting enough oxygen to their transplant. If this happens, patients will need to limit their wearing time with the scleral lens, or change to a different lens modality, such as a corneal gas permeable lens.

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The corneal topography for his left eye shows a high amount of irregularity

We placed a diagnostic Ampleye scleral lens: 4400 sag/ 8.04 BC/ -4.00 on his left eye to see what his vision potential could be, and he was able to achieve 20/20 vision with a +4.50 over-refraction! He was thrilled with the vision and comfort of the lens. When patients have an irregular corneal shape, I always place a diagnostic lens on top of their eye to see what their potential vision is. There have been times where the lens does not improve the vision, but it is better to find out now, instead of going through the whole fitting process.

Imagine barely seeing the big E on the vision chart and then improving the vision so that you can see the smallest line of letters! This is such a huge improvement in vision, and it will be life changing for this patient. It’s cases like these that put a huge smile on my face and warms my heart. I love helping patients see better!

We are excited to see him for his dispense in about 1 week.

Thank you Dr. Wellish for trusting us with this special patient!

Do Scleral Lenses Work for Everyone?

Do scleral lenses work for everyone?

Scleral lenses are becoming a very popular contact lens choice for a variety of patients. Scleral lenses have given us the ability to fit even the most complicated eyes. Scleral lenses are also very comfortable compared to other contact lens modalities. Corneal gas permeable lenses are notorious for their significant discomfort. While the vision is excellent in corneal GP lenses or hard contact lenses, the comfort can sometimes be unbearable, which leads many patients to discontinue wear.

Luckily, scleral contact lenses are much more comfortable, so many doctors select that as a first line approach. In the past, scleral lenses were used as a “last ditch effort.” Doctors would usually fit patients into corneal gas permeable lenses, hybrid lenses, and other lenses before reaching for a scleral lens.

While scleral lenses are a great option for many patients, not all patients can wear scleral lenses. Sometimes patients have a very difficult time inserting a scleral lens. They cannot hold their eyelids open far enough or perhaps their eye is too sensitive and blinks the lens right off of the eye. Also, some patients have eye conditions that will not support a scleral lens.

Corneal transplant patients often fall into this high risk category. Patients who’ve had corneal transplants are at greater risk for corneal edema and graft rejection. For this reason, many patients are unable to wear scleral lenses. Scleral lenses cover the entire cornea, which limits the amount of oxygen that gets to the transplant. The cornea requires oxygen to stay healthy. If the cornea cannot keep up with the oxygen demands, it can start to develop swelling, also known as edema. This swelling causes the transplant to become cloudy and then it causes the vision to become blurry.

Scleral lenses can also cause the corneal transplant to reject, which is very scary. This is why it is so important to follow up with your doctor. They need to assess the health of your eye and the cornea to ensure any contact lens is not causing any damage.

For many transplant patients, a corneal gas permeable lens is the best option. A corneal GP lens does not cover the entire cornea. Every time you blink, the contact lens moves and gets fresh tears underneath the lens to nourish the cornea. Patients who wear corneal GP lenses are at much less risk of corneal edema and transplant rejection compared to patients who wear scleral lenses.

If you have a corneal transplant, be sure to check with your eye doctor to find out what type of specialty contact lens is the best for your eye safety.

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Corneal transplant patient with glaucoma wearing a corneal gas permeable contact lens

CASE REPORT – CORNEAL TRANSPLANT PATIENT

Corneal transplant

Thank you Dr. Nyon for your kind referral today!

We had the pleasure of seeing a nice patient today who was kindly referred to us for a specialty contact lens consultation. She had a corneal transplant in the left eye over 15 years ago due to an infection in the left eye.

The patient reported that she used to wear soft contact lenses and then when she was in Florida 15 years ago, she felt something fly into her eye and her eye continued to feel worse and worse. By the end of the day, she was in the emergency room because her eye felt so bad.

She ended up having a super aggressive corneal ulcer and despite all of the treatments, her eye never recovered. She later got a corneal transplant.

She was fit into a mini scleral lens in the left eye 15 years ago and she had a major amount of redness and compression ring in that eye with the lens in, so she discontinued wearing it. She came today to see what options she had for the left eye.

After taking a look at her cornea, the transplant looks clear with a few spots of haze, but we do feel we can get her to see better with a gas permeable lens.

Due to the issue of the compression ring and eye redness, we feel a more custom scleral lens would be a good option for her.

Transplant patients are some of our favorite patients to help!

corneal transplant 1

corneal transplant 2

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Corneal Transplant Patient sees 20/25 with a Scleral Lens

Today we saw a patient kindly referred by Dr. Ochiltree from Mohave Eye Center.

A 69 year old white male arrived to our clinic for a contact lens consultation. He has a full thickness corneal transplant in each eye from keratoconus. He wears spectacle glasses, however, he was looking to further improve his vision.

Prior to the corneal transplants, he wore gas permeable lenses, and he complained that they popped out of his eyes.

After reviewing the images with him, along with an evaluation of his eye health, we suggested trying a diagnostic lens on in office, to check his vision potential. Often times, if I am concerned with the best potential vision or if the patient has concerns, we will try on a lens and perform a quick over-refraction to check the visual acuity, visual quality, and overall comfort of the lens. Then, we can all make an educated decision whether or not to move forward with the fitting process.

The astigmatism in the right and left eye both look fairly regular, so it is possible that he might do well in a traditional bitoric corneal gas permeable lens. However, with the limbus-to-limbus astigmatism in the left eye, he may experience frequent lens dislodgement. The right eye looked like a better candidate, but the elevation maps showed a huge difference, and I worried about the lens dislodgement issue again.

We tried on an Ampleye Scleral lens 4400 sag in each eye. Both lenses showed corneal touch, so I removed those lenses and we inserted the 4800 sag instead. The central clearance looks acceptable and with a quick over-refraction, he was able to achieve 20/25 vision, and he was thrilled with the comfort of the lenses.

Since he decided to proceed, we continued the fitting process by letting the lenses settle for 20 minutes, and then took external images of the fit and OCT images. All information was sent to the lab and the consultants helped us design his lenses. Looking forward to seeing him at the dispense visit!

Dr. Woo’s tip of the day: If you are concerned with the potential vision or comfort (or the patient is), use a diagnostic lens and perform a quick over-refraction to gauge the patient’s best corrected visual acuity.

Corneal Transplant Patient Fit With Custom Scleral Lens

We had the pleasure of seeing one of our keratoconus patients today for a specialty contact lens fitting for his right eye.

This patient has advanced keratoconus in both eyes. Last year, Dr. Stafeeva performed a corneal transplant on the right eye due to the advanced keratoconus disease. Many patients who have scarring on the front of their eye from keratoconus require a corneal transplant. She was waiting for the transplant to heal up on the right eye so she could perform cataract surgery (he had a visually significant cataract on the right eye as well).

In the meantime, we were focusing our efforts on his left eye to help improve the vision and the fit of the scleral lens. He has advanced keratoconus in the left eye with central scarring. He was fit with a scleral lens from another clinic, but when he saw us, the cornea had changed shape, and he advanced to the point where the cornea was touching the inside of the scleral lens. It is not safe for the scleral lens to touch the cornea, so it was important that we re fit him into a safer scleral lens design. He had a standard intraocular lens from cataract surgery in the left eye, as well as a scleral buckle from a prior retinal surgery. Since his eye was a very complicated case, we recommended a more custom scleral lens. A more custom fit scleral lens helps with lens comfort and can decrease redness.

We saw him in the summer of 2020 and ended up fitting his left eye into an EyePrint Prosthetic. With that lens, he was able to achieve 20/60 vision.

Today, we decided to fit his right eye into the Latitude scleral lens. We felt that because of his corneal transplant, along with the toric IOL in the right eye, a custom scleral lens would be the best option for him. With an over refraction of +2.00-3.50×116, he ended up achieving 20/15 vision! The Latitude scleral lens is a great choice for him because the custom fit of the lens will help to center and stabilize the optics of the scleral lens. This will allow for the best possible vision.

We are very excited for his Latitude scleral lens to arrive! With the amount of astigmatism, we did educate him that it could take 1 or 2 additional lenses to center the optics, but we do feel very good about the fact that he will be able to achieve such great vision.

Thanks for Dr. Stafeeva for thinking of us for this fun case!

Corneal Transplant Patient Fit With Gas Permeable Contact Lens

Kind referral of a corneal transplant patient from Dr. Shibiyama from UCLA/Jules Stein!

Older gentleman with a history of keratoconus in each eye. He had bilateral transplants back in the 1970’s and 1980’s and they held up for quite some time!

He also has a history of glaucoma with bleb surgery in each eye, and a shunt in the right eye.

The right eye underwent cataract surgery 2 years ago, and also received a new corneal transplant in March, and is ready to be re-fit into a new specialty contact lens.

The left eye transplant looks great, however, due to a large cataract, his vision is limited in that eye. He is wanting to get the right eye fit with a contact lens prior to proceeding with cataract surgery in the left eye.

The left eye has a hugely elevated bleb, so the corneal lens was specifically designed by Dr. Shibiyama to decenter laterally and inferiorly to protect the bleb.

The topography did not look severely irregular in the right eye, so I chose the ACE corneal gas permeable fitting set. The 7.0 base curve actually centered quite well, and I was pleased with the fluorescein pattern. With an over-refraction, he could achieve 20/80 vision. Despite a beautiful transplant and clear IOL, the vision is limited due to his advanced glaucoma.

With the help of Art Optical expert consultants Bethany and Erik, we designed the lens and got it ordered. Will keep you posted on his results!