myoring in pellucid marginal degeneration
TRANSCRIPT
FULL RING INTRACORNEAL IMPLANTATION IN PMD
Sahar Mojaled Nobari( PhdC), Consuelo Villena(PhD), Khosrow Jadidi (PhD)
INTRODUCTION
MyoRing is a full ring intracorneal implant that
inserts into the cornea using the Pocketmaker
Microkeratome or femtosecond laser. The use of
MyoRing implantation has proven to be safe and
effective procedure in patients with high myopia,
post lasik ectasia and keratoconus.
INTRODUCTION
This study evaluates the visual and refractive
outcomes as well as the patient´s satisfaction and
ocular symptoms after MyoRing implantation in
patients with Pellucid Marginal Degeneration
(PMD). To our knowledge this is the first study on
MyoRing implantation in patients with PMD
PATIENTS & METHODS Retrospective study : 15 eyes of 15 patients,(11males & 4 females) ranging in age from
22 to 49 years old
Surgical technique : MyoRing implantation using PocketMaker Microkeratome
Follow-up : 10 months (range 6-12 months)
Inclusion criteria : poor visual acuity with spectacle,contact lens intolerance or
dissatisfaction, clear central cornea, minimum corneal thickness 360 microns and mean
keratometry between 45 to 52 diopter
Exclusion criteria : other ocular disease, pregnancy, diabetes , previous ocular surgery
Diagnosis : slit lamp examination ( inferior corneal thining, ectasia above the area the
maximum thining ), Corneal topography( butterfly or kissing birds pattern) and
refractive finding (against–the-rule astigmatism with CDVA loss)
Patients were asked about their visual symptoms and general satisfaction , based on 6-
point subjective likert scale to score them
Visual and Refractive OutcomesParameter Preoperative postoperative p-value
UCVA (log MAR)Mean ± SD 1.13 ± 0.21 0.24 ± 0.12 <0.001
Range 0.7 to 1.30 0 to 0.50
BCVA (log MAR)Mean ± SD 0.40 ± 0.12 0.18 ± 0.09 <0.001
Range 0.3 to 0.7 0 to 0.4
Sphere(D)Mean ± SD -3.20 ± 3.4 0.01 ± 1.9 <0.001
Range -10 to 0 -5.00 to 2.50
Cylinder(D)Mean ± SD -5.50 ± 1.2 -1.70 ± 1.00 <0.001
Range -7.00 to -3.00 -3.50 to 0
Spherical Equivalent(D)Mean ± SD -6.00 ± 3.6 -0.70 ± 1.9 <0.001
Range -13.00 to -1.75 -6.00 to +1.75
Mean of the Keratometric (K) Values Preoperatively and Postoperatively as Well as the Amount of Reduction.
K- Readings Preoperative Postoperative Pre-Postǂ P-value
Kmax (D) 51.1 ± 2.4 46.1 ± 2.00 5.00 D <0.001
Kmin (D) 44.8 ± 2.00 43.7 ± 2.1 1.10 D <0.001
Kaverage (D) 48.0 ± 2.2 44.0 ± 2.6 4.00 D <0.001
A significant reduction was observed in maximum, minimum and average keratometry after MyoRing implantation.
Visual Symptoms and Patient´s Satisfaction Score Postoperatively (based on 6-point likert scale)
parameters No Very low Low Moderate High Very high
Halo (%) 5 (33.3) 5 (33.3) 2 (13.3) 2 (13.3) 1 (6.7) 0
Glare (%) 5 (33.3) 3 (20) 5 (33.3) 1 (6.7) 1 (6.7) 0
Night Vision (%) 6 (40) 2 (33.3) 3 (20) 4 (26.7) 0 0
Fluctuation (%) 9 (60) 4 (26.7) 2 (6.7) 0 0 0
Activity Limitation (%) 12 (80) 2 (13.3) 1 (6.7) 0 0 0
Overall Satisfaction (%) 0 0 1(6.7) 2(13.3) 5 (33.3) 7 (46.7)
CONCLUSION MyoRing implantation by means of PocketMaker
Microkeratome appears to be a safe and effective method for treating pellucid marginal degeneration.
Both UCVA and BSCVA improved significantly. The improvement in UCVA was remarkable ( 9 lines of snellen acuity)
The considerable corneal flattening is due to the circular shape of MyoRing which leads to a more significant arc-shortening effect on the cornea
All patients were satisfied with MyoRing implantation
Further randomized, prospective studies with longer follow-up period is recommended to evaluate the stability of MyoRing implantation and its impact on disease progression