1. Boris Severinsky, MOptom, FBCLA
Efficacy and Safety of Synergeyes contact lenses shortly after CXL procedure: case report series
Boris Severinsky, MOptom, FBCLA
Conflict of interests: none
Funding: none

2. Corneal Cross-Linking (CXL)
CXL can halt the progression of corneal ectasia (Wollensak et al – 2003)
Our experience: Aug 2007 till May 2013, eyes underwent CXL
About 50% of our patients used various modalities of contact lenses (CL) prior to CXL
Literature: 50-70% of KC patients use CL (Zadnik et al. CLEK study-2005)
Should post CXL fitting approach be different???
The aim of CXL is to stop progression of corneal ectasia by promoting biomechanical stabilization and increasing corneal stiffness. Since the procedure is not yet widely done in the US, I allow to myself to bring some numbers from our clinic. The first eye was treated in August Till the last May, 409 eyes underwent cross-linking.
Many of CXL candidates are contact lens dependent prior to the procedure and will require visual correction after. In our clinic more than half of the treated patients used CL. The question that arising should the CL fitting approaches shortly after the procedure be different.

3. Corneal recovery after CXL
Continuous healing and reshaping process:
Epithelial cells regeneration - 4 days¹
Epithelial remodeling (initial steepening),first months
Corneal nerves recovery – 6 months
Progressive flattening and regularization
0 m, VA Spec 0.3 VA CL (soft) 0.5
2.5 m, CXL Haze, Minor flattening
9 m, VA CL(soft) 0.9
>2 D of flattening
Corneal recovery after cross-linking is not uniform.
Although epithelial cells regeneration completed in the first 4 days, delayed epithelial healing may lasts for period of up to 6 months
In early period changes, such as corneal thinning and steepening that later followed by returning to original shape, taking place, The explanation of these phenomena is continuous epithelial remodeling.
The epithelial remodeling is a point of interest for CL fitters because it leads to corneal shape fluctuations. The Initial steepening coincides with the re-epithelialization process and with keratocyte apoptosis and repopulation. After the first month progressive corneal flattening and central corneal regularization are frequent. Taking in account these changes a special precaution should taken when fitting recently cross-linked cornea with CL.
1. Mazzota C. AJO 2008

4. Complexity of CL fitting post CXL: RGP’s
Mechanical traumatic effect
Epithelial and anterior stroma disruptions
Inflammatory response (Lema I. Cornea 2008)
Hyposensitivity due to corneal nerves loss
Risk of microbial keratitis (CL related)
Conclusions: RGP CL use after CXL is associated with a delay in the regeneration of the CSNP and epithelial cell stress.
Uneventful CXL LE Complete healing: 4 d
3w. Starts to wear old RGP lens
5w: Central infiltrative ulcer
Despite of being considered as a gold standard, RGP lenses frequently lead to corneal micro-trauma and erosions especially when the fit is flat. But even with apical clearance epithelial and stromal disruptions are frequent. During the healing period the epithelium is soft, with reduced quality of adherence between epithelial layers, thus CL induced epithelial compression may have a harmful effect on epithelial remodeling. This recently published study describes a potential risk of delayed corneal nerves regeneration and decrease in basal epithelial cells attributed to the use of RGP lenses shortly after CXL.

5. Complexity of CL fitting post CXL: Hydrogel Lenses
Fitted up to 1.0 mm flatter than Kmax
Increased thickness (stiffness ↑, permeability↓)
Erosions & demolding similar to RGP’s
SiHy Mini-Sclerals (Severinsky B. Clin Expt Opt, 2013)
Specialty soft lenses for keratoconus utilize increased central thickness for optical neutralization. Because these lenses are usually fitted much flatter than underlying cornea, corneal erosions and demolding may occur, as similar to rigid lenses. However new approaches, such as soft mini-sclerals are available now. These lenses rest on the sclera, like GP scleral lenses, and minimally bear the corneal apex.

6. Compromised Ocular Surface
Prolonged CL use (micro-trauma, recurrent erosions)
Cell-toxicity by solutions with preservatives
Allergies
CXL is photo-chemical reaction with the release of free radicals
Dry eyes
Corneal hyposensitivity
Chronic Inflammation
We should always remember that Keratoconus patients may have COMPROMISED OCULAR SURFACE . That’s the reason Why MINIMAL CL INFLUENCE ON RECOVERING CORNEA & PROPER O2 LEVELS are so important?
One of the keys for successful management after CXL is to keep the patient in the best ocular conditions before and during CL wear.
IMPORTANCE OF MINIMAL CL
INFLUENCE ON
RECOVERING CORNEA

7. Hybrid Lenses after CXL
Soft skirt lands over para-limbal
sclera and peripheral cornea
Clearance over the central cornea/treated zone!
Lens Type
Permeability
Central RGP
Soft skirt
Synergeyes KC (KC)*
100
9.3
ClearKone (CK)*
UltraHealth (UH)*
130
84 !!!
So why hybrid lenses after CXL is a good option? Avoidance of contact with the treated zone is by far the major advantage of this modality. Hybrid lenses rest on the sclera and peri-limbal cornea and vault the central cornea with no support over it.
There are three options currently available from Synergeyes. KC series comprise of aspherical central RGP button (baten) with DK value of 100 and hydrogel skirt with Dk of about 9. ClearKone lenses featured by the reverse geometry design of the rigid portion. Flatter b.c. ensures better VA and bears less on the peripheral cornea.
Ultrahealth that is the latest development has significantly improved oxygen permeability of both the skirt and the center and improved design of the junction area.
An adequate amount of oxygen is crucial for recovering cornea and here UH lenses posses clear advantage over the predecessors.
*- Synergeyes KC, CK and UH are trade marks of SynergEyes®, Inc., Carlsbad, CA

8. Patients and Methods Studied period May 2012 to June 2013
23 eyes of 18 pt. (6f/12m); KC=21, ectasia=2
Mean age 26.2±7.1, range 16-38
Success criteria: CL wear of ≥ 3 months
CL fitted 4.3±2.2 (range ) months after CXL
The goal of proposed design was to minimally interfere with corneal recovery after CXL procedure.
it is important to evaluate
the influence and safety of use of contact
lenses on the cornea in the first months after
collagen cross-linking.
Our aim was to evaluate the efficacy and complications rate of hybrid lenses in early stages after the cross-linking procedure. We analyzed the visual acuity improvement and corneal adaptation in the first 20 eyes fitted with three types of Synergeyes lenses over one year period. Only patients previously failed with RGP’s or neophytes were included in the study
Success was defined as regular lens wearing of at least 3 months after fitting. CL were fitted in average 4 months after the treatment. Topographical values and VA improvement were evaluated on lens dispensing and after three months of lens wearing.

9. Results: Efficacy BCVA CL 0.74±0.14, range 0.5-1.0
BCVA Refr ±0.12 (p <0.001)
Mean Kmax=56.0 ± 5.6D, range D
Mean Pach= 420 ± 40 μm
Lens
VA, Refr
VA, CL
Kmax, D
Kmax, D
3 mo.
CK,
n=4
0.3
0.6
60.8 !
58.8
NS (p=0.45)
KC, n=11
0.45
0.75 56
55.3
NS (p=0.78)
UH,
n=8
0.43
0.79
53.7
52.9
NS (p=0.73)
The VA significantly improved with the CL. Eyes fitted with Clear Kone lenses have demonstrated significantly higher Kmax and refractive astigmatism values, thinner pachimetry and slightly decreased corrected vision, than eyes in other groups. Eyes with lower Kmax and higher pachimetry values achieved better CL corrected vision, as may be expected. The mean BCVA was about 20/25. But even eyes with Kmax of 60 or higher achieved reasonable visual results. After three months period all fitted eyes have shown a trend to corneal flattening, probably because of CXL effect, but not clinically significant

10. Results: Safety Mean follow-up 5.6±3.1 (range 2-12) mo.
Wearing time 10.2 h/day, (range 6-14)
Success rate ≈90% (16 of 18 patients)
Drop out due to: intolerance (1), extreme central flattening (1)
Pre CXL
4 m. post CXL
daily wearing time ranged from 6 to 12.5 hours with mean value of about 10 hours a day. 15 of 16 fitted patients continue to wear their lenses. An average 1.4 lenses per eye were fitted during the study period.
Two patients have stoped to wear CL, one shortly after dispensing due to intolerance and the other due to developed extreme central flattening. This flattening made able wearing of disposible soft toric lens satisfactory vision.

11. Complications - CL CK, n=4 3 - 1 KC, n=11 2 4 UH, n=8
Lens Type
Central erosions
Sterile Infiltrates
Corneal edema
Significant
SPK’s
CK, n=4 3 - 1
KC, n=11 2 4
UH, n=8
6 m post-CXL, K max 64.6 D
ClearKone
100 µm apical clearance
After lens removal
Regarding the complications. As you can see wearing of CK lenses was highly correlated with corneal erosions events and one case of transcient epithelial edema.
Eyes fitted with KC series showed a trend to develop sterile corneal infiltrates under the junction area.
Use of UltraHealth lenses was associated with no significant adverse effects, except SPK’s in two cases.

12. Complications - CXL OS-uneventful CXL 8 days later fungal keratitis
Pre CX CL trials → poor VA & intolerance
Scaring → central flattening - BCVA 0.5+

13. Troubleshooting Junction bearing, ring erosion
UH lens
KC lens
Junction bearing, ring erosion
KC lenses: steeper skirt
UH lenses (settling back):
flatter skirt, increase vault
Wait at least - ???h.
Central erosions –
Piggyback by Hyper Dk soft CL
(N&D, Total - 1)
A couple of words about problem solving. The vast majority of corneal erosion was induced by the lens settling down. In these cases modifications of the skirt fit should be done. For KC lenses it is skirt steepening or vault increase or skirt flattening for UH lenses. Although the extent of erosions and especially junction imprints was much lesser with the UH series.
If central staining exists even the fit is correct piggybacking should be considered as an option. Plano powered high Dk lenses may be worn prior to hybrid lens insertion or simply putted into the lens bowl.
Lens type
PB (N&D; 8.60; -0.50) CK 1 KC 3 UH
Total
5 (21%)

14. Troubleshooting Lens adhesion, steepening (suction effect)
Fenestrate ?
Skirt calcification (UH),
Ca3(PO4)2 oversaturation
Stop H2O2 & switch to MPS
Daily surfactant cleaners (Lobob)
Piggybacked RGP’s
Calcium phosphate oversaturation in tears of some individuals

15. Conclusions
Hybrid CL are an effective option for vision restoration shortly after CXL
UH design demonstrated less deleterious influence on corneal integrity
Trend to CXL induced corneal flattening
The bios of CL fitting after CXL is minimally interact with the treated zone to provide the most natural biological recovery
In light of growing interest in CXL, the need for special contact lens modalities will increase. Synergeyes contact lenses provide successful visual rehabilitation after corneal collagen cross-linking. UH lenses demonstrated minimal influence on corneal health, likely due to better oxygen permeability and improved lens design.
Still complications of corneal epithelium may exist, and thus closer monitoring is advisable to ensure an avoidance of contact with the treated zone.

16. Thank you for your attention!