Rezumat. Keratoconusul este o patologie oculară multifactorială asimetrică a corneei, caracterizată prin protruzia progresivă și
subțierea corneei, ceea ce duce la scăderea acuității vizuale. Cross-linkingul este unica metodă dovedită științific ca fiind
eficientă în stoparea progresării keratoconusului, dar ea nu poate fi aplicată la o grosime a corneei mai mică ca 400 μm.
Transplantul membranei Bowman a fost aplicat pe 52 de pacienți cu keratoconus avansat, având rezultate postoperatorii
foarte bune și fără complicații.
Introduction. Keratoconus (KC) – a multifactorial,
asymmetric corneal disorder characterized
by progressive corneal protrusion and thinning,
leading to increasing visual acuity. Corneal collagen
cross-linking (CXL) is the only proven intervention
that can halt disease progression in KC, but the
corneal thickness of less than 400 μm is considered
a contraindication. Penetrating keratoplasty (PK)
or deep anterior lamellar keratoplasty (DALK) are
treatment options for the advanced cases of KC. In
advanced studies, scleral contact lenses are the safe
save and effective way of visual acuity optimizing
for patients.
Purpose. To study the results after 5 - year of
Bowman layer transplantation (BLT) in to the stromal
pocket in eyes with advanced keratoconus
(KC). Center for Eye Diseases
Materials and methods. Fifty two eyes of 52
patients with average age 28 years (range 5,3) with
advanced KC which are not suitable for ultraviolet
cross-linking or intrastromal corneal rings, CTP (corneal
thinnest point) ≤ 400 μm and Kmax (maximum
keratometry) ≤ 58 D.) underwent BLT by one experienced
surgeon in Helmholtz National Medical Research.
Preoperative patient examination included
recording the decimal best spectacle-corrected
visual acuity (BSCVA) determined on the Snellen
chart, best contact (scleral) lens corrected visual
acuity (BCLVA), Scheimpflug based corneal tomography,
slit lamp biomicroscopy, optical coherence
tomography, endothelial cell density (ECD) evaluevaluation.
The same examinations were performed 3, 6
and every 12 months postoperatively in all cases.
All patients reached a minimum follow-up of 14
months (mean follow-up 30,7 months, range±8,9).
Results. There were no intraoperative or postoperative
complications. In our cases of 52 eyes underwent
BLT into a manually dissected mid-stromal
pocket with an average follow-up 30,7 months, the
Kmax and BCLVA were stable. The mean CTP was
decreased from an average preoperative value of
398±37 to 378 ± 54,3 microns and no decrease in
endothelial cell density was found. Topical treatment
with antibiotics, dexamethasone and lubricants
four times daily during 4 weeks. Therefore,
also after BL transplantation, patients should be
counseled about the possible impact of eye-rubbing,
and allergies may need closer monitoring and
treatment. No postoperative complications were
observed in any of the other cases
Conclusion. In this study, the clinical outcome
of BLT stabilizes the KC and saves host tissue as it is
palliative care. Extraocular technique and absence
of corneal sutures are the main advantages of BLT.
There were no complications and lost lines more
than 1 of BCLVA. In this group of patients, BLT could
become a supplementary treatment option in the
management of advanced keratoconus to postpone
PK or DALK and to minimize the risk of longterm
complications and save preoperative BCLVA.
