Title: Comparative%20refractive%20outcomes%20following%201.8%20mm%20bimanual%20cataract%20surgery%20versus%203.2%20mm%20coaxial%20cataract%20surgery
1Comparative refractive outcomes following 1.8 mm
bimanual cataract surgery versus 3.2 mm coaxial
cataract surgery
- M. Usman Saeed FRCOphth, Farrukh Ali FRCS,
- M.Salman Saeed MBBS, BV Kumar FRCS,
- Som Prasad FRCOphth, FACS
The first four authors have no financial interest
in the subject matter of this poster Som Prasad
has received travel reimbursements from Bausch
Lomb, Alcon, Novartis Pfizer
2The issue is whether two 1.8 mm incisions produce
a better refractive result than a single 3.2 mm
incision 2 side ports
1 x 2.75 mm incision enlarged to 3.2 mm 2 side
ports
2 x 1.6 mm incisions
3Coaxial versus Bimanual
Coaxial phacoemulsification Note small side-port
and main port with phaco probe and sleeve
Bimanual phacoemulsification Note 2 almost
equal sized ports and phaco probe without a
sleeve
4Method
- Retrospective review of pre operative, post
operative and surgical notes of patients
undergoing cataract surgery by one surgeon - Prospective data collection on an electronic
patient record database - Appropriate departmental approvals were obtained
before reviewing individual electronic records
5Method
- Data collection was done and converted to a
microsoft excel spreadsheet - Pre operative data and post operative data to was
transposed to negative cylinder notation - Refractive surgical effect was calculated for
each patient considering the target refraction,
post op refraction and pre op refraction
RSE formula as written by Mr. Stephen B Kaye
FRCOphth
6Method
- Group 1 (MICS) cataract surgery by bimanual
micro-incision cataract surgery (MICS) with
insertion of an intra-ocular lens implanted in
the bag through a 1.8 mm superior incision. - Group 2 (SICS) eyes had undergone cataract
surgery using conventional coaxial
phacoemulsification (SICS) cataract surgery with
2.75 mm superior incision enlarged to 3.2 mm for
IOL insertion. - No other refractive procedures were undertaken
simultaneously during surgery.
7Results
- 194 records were identified and included
- Group 1 Bimanual MICS n 97
- Group 2 Coaxial SICS n 97
- The intended post operative refractive aim for
group 1 was -0.26 dioptres (average) and for
group 2 was -0.21 dioptres (average).
8Group 1 Bimanual 1.8 mm MICS
- In Group 1 (MICS with 1.8 mm superior incision),
the average aimed post operative refraction was
-0.26 dioptres (range 0.3 to -1.12 dioptres). - The mean of refractive surgical effect was -0.03
dioptre sphere with 0.38 Dioptre cyl with a
calculated nearest spherical equivalent of 0.16
dioptres (average). (p0.0001)
9Group 2 Coaxial 3.2 mm
- In Group 2, (SICS with 3.2 mm superior incision),
the average aimed post operative refraction was
-0.21 dioptres (range 0.5 to -0.60 dioptres). - The mean of refractive surgical effect was -0.31
dioptre sphere with 0.66 dioptre cyl range with
a calculated nearest spherical equivalent of
0.02 dioptres (average). (plt0.00001)
10Target refraction versus post op refraction data
Target refraction Target refraction Target refraction Target refraction Refractive surgical effect Target aim RSE post op Refractive surgical effect Target aim RSE post op Refractive surgical effect Target aim RSE post op Refractive surgical effect Target aim RSE post op Post operative data Post operative data Post operative data Post operative data
NES Sphere cyl Axis NES Sphere Cyl Axis Nes Sphere Cyl Axis
Group 1 (1.8 mm) -0.26 -0.26 0 0 0.16 -0.03 0.38 177 -0.09 -0.26 0.34 177
Group 2 ( 3.2 mm ) -0.21 -0.21 0 0 0.02 -0.31 0.66 10.87 -0.17 -0.46 0.59 10.87
Difference between difference to target refraction in group 1 2 Difference between difference to target refraction in group 1 2 Difference between difference to target refraction in group 1 2 Difference between difference to target refraction in group 1 2 Difference between difference to target refraction in group 1 2 -0.04 0.36 115.2
11Conclusion
- Bimanual cataract surgery with 1.8 mm incision
appears to induce a 0.38 dioptre change in
astigmatism. - Conventional coaxial phacoemulsification with 3.2
mm incision appears to induce a 0.66 dioptre
change in astigmatism. - The smaller change in astigmatism associated with
smaller incision size is statistically
significant. - This may be considered a step towards achieving
astigmatically neutral corneal incisions.