Thermal Study of Longitudinal and Thermal Study of Longitudinal and Torsional Ultrasound Torsional Ultrasound PhacoemulsificationPhacoemulsification::

Tracking the Temperature of Corneal Tracking the Temperature of Corneal Surface, Incision and HandpieceSurface, Incision and Handpiece

Bokkwan Jun MD, John P Berdahl MD, Terry Kim MD*Bokkwan Jun MD, John P Berdahl MD, Terry Kim MD*

Duke University Eye CenterDuke University Eye CenterDurham, North CarolinaDurham, North Carolina

Supported by a research grant from Alcon, Inc., Consultant, Alcon, Inc.*

PurposePurpose To investigate the change and difference in To investigate the change and difference in

temperature at the corneal surface, incision, temperature at the corneal surface, incision, and handpieceand handpiece Two different modalities of ultrasoundTwo different modalities of ultrasound

• LongitudinalLongitudinal• Torsional Torsional

Two different sizesTwo different sizes of incisionof incision• Standard (2.75mm) Standard (2.75mm) • Microincisional (2.2mm)Microincisional (2.2mm)

To observe thermal effect on the woundsTo observe thermal effect on the wounds

Operating microscopyOperating microscopy Scanning electron microscopy (SEM) Scanning electron microscopy (SEM)

MethodsMethods Prospective studyProspective study

Twelve human cadaver eyesTwelve human cadaver eyes Four groups of 3 eyes/group Four groups of 3 eyes/group

• Group 1:Group 1: 2.75mm, 100% longitudinal 2.75mm, 100% longitudinal• Group 2:Group 2: 2.2mm, 100% longitudinal 2.2mm, 100% longitudinal• Group 3:Group 3: 2.75mm, 100% torsional 2.75mm, 100% torsional• Group 4:Group 4: 2.2mm, 100% torsional 2.2mm, 100% torsional

System settings and accessoriesSystem settings and accessories Fluidics: Fluidics: Vacuum: 300mmHg, Aspiration: 12cc/min, Bottle height: Vacuum: 300mmHg, Aspiration: 12cc/min, Bottle height:

100cm and simulated On/Off occlusion approx. every 7 seconds100cm and simulated On/Off occlusion approx. every 7 seconds Phacoemulsification time: Phacoemulsification time: ~ 40 seconds with full power and ~ 40 seconds with full power and

instrument manipulation to simulate surgical useinstrument manipulation to simulate surgical use Tip: Tip: Mini-Flared 30° Kelman tipMini-Flared 30° Kelman tip Sleeve: Sleeve: MicroSleeve for 2.75mm, UltraSleeve for 2.2mmMicroSleeve for 2.75mm, UltraSleeve for 2.2mm

ThermocameraThermocamera (ThermaCAM(ThermaCAMTMTM, FLIR system, Danderyd, Sweden), FLIR system, Danderyd, Sweden)

Thermal images were captured every 5 secThermal images were captured every 5 sec The temperature of three areas was measuredThe temperature of three areas was measured

1.1. Corneal surfaceCorneal surface2.2. IncisionIncision3.3. HandpieceHandpiece

Operating microscopyOperating microscopy To observe wound burn with OR microscopeTo observe wound burn with OR microscope (whitening and edema of the wound edge)(whitening and edema of the wound edge)

Scanning electron microscopyScanning electron microscopy (SEM)(SEM)

MethodsMethods

123

The average of maximum temperature of incision, The average of maximum temperature of incision, handpiece and corneal surface in each grouphandpiece and corneal surface in each group

ResultsResults

Max temperature (°C)

IncisionIncision Handpiece Corneal surface

Group 1(2.75mm, 100% longitudinal)

45.945.9 43.7 39.5

Group 2Group 2(2.2mm, 100% longitudinal)(2.2mm, 100% longitudinal)

47.747.7 44.744.7 41.941.9

Group 3(2.75mm, 100% torsional)

33.233.2 27.4 25.5

Group 4(2.2mm, 100% torsional)

37.237.2 30.2 29.8

ResultsResultsGroup 1 Group 1 (2.75mm, 100% longitudinal) Group 2 Group 2 (2.2mm, 100% longitudinal)

Group 1 Group 1 (2.75mm, 100% torsional) Group 1 Group 1 (2.2mm, 100% torsional)

Comparison of Thermal images Comparison of Thermal images at maximum temperatureat maximum temperature

ResultsResults Temperature changes of corneal surface, incision and Temperature changes of corneal surface, incision and

hand piecehand pieceGroup 1 Group 1 (2.75mm, 100% longitudinal)

Group 3 Group 3 (2.75mm, 100% torsional)

Group 2 Group 2 (2.2mm, 100% longitudinal)

Group 4 Group 4 (2.2mm, 100% torsional)

15

20

25

30

35

40

45

50

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(°C

)

Corneal surface

Incision

Handpiece

15

20

25

30

35

40

45

50

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(°C) Corneal surface

Incision

Handpiece

15

17

19

21

23

25

27

29

31

33

35

37

39

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(°C

)

Corneal surface

Incision

Handpiece

1517192123

2527293133353739

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(°C) Corneal surface

Incision

Handpiece

Comparison of incision temperature with 2.75mm and 2.2mm incision

ResultsResults

15

20

25

30

35

40

45

50

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(C)

2.75, 100% longitudinal

2.2, 100% longitudinal

Group 1

(2.75mm, 100% longitudinal)

vs

Group 2

(2.2mm, 100% longitudinal)

Group 3

(2.75mm, 100% torsional)

vs

Group 4

(2.2mm, 100% torsional)

(p=0.002)

(p<0.001)

15

20

25

30

35

40

45

50

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(°C

)

2.75, 100% torsional

2.2, 100% torsional

Comparison of incision temperature between longitudinal and torsional groups

ResultsResults

15

20

25

30

35

40

45

50

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(C

)

2.75 longitudinal

2.75 torsional

15

20

25

30

35

40

45

50

<0 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50

Time (sec)

Tem

pera

ture

(C

)

2.2 longitudinal

2.2 torsional

Group 1

(2.75mm, 100% longitudinal)

vs

Group 3

(2.75mm, 100% torsional)

Group 2

(2.2mm, 100% longitudinal)

vs

Group 4

(2.2mm, 100% torsional)

(p<0.001)

(p<0.001)

ResultsResults

Operating microscopy

Group 1 and 2 (longitudinal US groups)• Wound burn (whitening and edema of the

wound edge) was observed in 6/6

• Incision temperature was 43~45 when ℃the first sign of wound burn was observed

Group 3 and 4 (torsional US groups)• No wound burn was evident in 0/6

ResultsResults (SEM, endothelial view)(SEM, endothelial view) SEM images demonstrating wound gap of inner surface SEM images demonstrating wound gap of inner surface

and partial loss of Descemet’s membraneand partial loss of Descemet’s membrane

Group 1 Group 1 (2.75mm, 100% longitudinal) Group 2 Group 2 (2.2mm, 100% longitudinal)

Group 3 Group 3 (2.75mm, 100% torsional) Group 4 Group 4 (2.2mm, 100% torsional)

ConclusionsConclusions

Incision temperatureIncision temperature Can be influenced by ultrasound modality.Can be influenced by ultrasound modality. Was significantly lower in torsional ultrasound as Was significantly lower in torsional ultrasound as

compared to longitudinal ultrasound. compared to longitudinal ultrasound. To a lesser extent, smaller incisions may also increase To a lesser extent, smaller incisions may also increase

incision temperature, but not to a significant degree.incision temperature, but not to a significant degree.

The combination of torsional ultrasound and The combination of torsional ultrasound and small incisionssmall incisions A safe way to decrease the risk of wound burn in A safe way to decrease the risk of wound burn in

patients with dense cataracts.patients with dense cataracts.