Abstract
Aim: To systematically refine and recommend parameter settings of spot size, power, and treatment duration using the Pascal® photocoagulator, a multi-spot, semi-automated, short-duration laser system. Materials and Methods: A retrospective consecutive series with 752 Caucasian eyes and 1242 laser procedures over two years were grouped into, (1) 374 macular focal / grid photocoagulation (FP), (2), 666 panretinal photocoagulation (PRP), and (3) 202 barrage photocoagulation (BP). Parameters for power, duration, spot number, and spot size were recorded for every group. Results: Power parameters for all groups showed a non-gaussian distribution; FP group, median 190 mW, range 100 - 950 mW, and PRP group, median 800 mW, range 100 - 2000 mW. On subgroup comparison, for similar spot size, as treatment duration decreased, the power required increased, albeit in a much lesser proportion than that given by energy = power x time. Most frequently used patterns were single spot (89% of cases) in FP, 5 × 5 box (72%) in PRP, and 2 × 2 box (78%) in BP. Spot diameters as high as ≈ 700 m on retina were given in the PRP group. Single session PRP was attempted in six eyes with a median spot count of 3500. Conclusion: Overall, due to the small duration of its pulse, the Pascal® photocoagulator tends to use higher powers, although much lower cumulative energies, than those used in a conventional laser. The consequent lesser heat dissipation, especially lateral, can allow one to use relatively larger spot sizes and give more closely spaced burns, without incurring significant side effects.
| Original language | English |
|---|---|
| Pages (from-to) | 87-91 |
| Number of pages | 5 |
| Journal | Indian Journal of Ophthalmology |
| Volume | 59 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Mar 2011 |
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Keywords
- Barrage photocoagulation
- focal photocoagulation
- laser power
- laser spot size
- laser treatment duration
- panretinal photocoagulation
- pascal® photocoagulation
ASJC Scopus subject areas
- Ophthalmology
Cite this
Experience with the Pascal® photocoagulator : An analysis of over 1200 laser procedures with regard to parameter refinement. / Sheth, Saumil; Lanzetta, Paolo; Veritti, Daniele; Zucchiatti, Ilaria; Savorgnani, Carola; Bandello, Francesco.
In: Indian Journal of Ophthalmology, Vol. 59, No. 2, 03.2011, p. 87-91.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Experience with the Pascal® photocoagulator
T2 - An analysis of over 1200 laser procedures with regard to parameter refinement
AU - Sheth, Saumil
AU - Lanzetta, Paolo
AU - Veritti, Daniele
AU - Zucchiatti, Ilaria
AU - Savorgnani, Carola
AU - Bandello, Francesco
PY - 2011/3
Y1 - 2011/3
N2 - Aim: To systematically refine and recommend parameter settings of spot size, power, and treatment duration using the Pascal® photocoagulator, a multi-spot, semi-automated, short-duration laser system. Materials and Methods: A retrospective consecutive series with 752 Caucasian eyes and 1242 laser procedures over two years were grouped into, (1) 374 macular focal / grid photocoagulation (FP), (2), 666 panretinal photocoagulation (PRP), and (3) 202 barrage photocoagulation (BP). Parameters for power, duration, spot number, and spot size were recorded for every group. Results: Power parameters for all groups showed a non-gaussian distribution; FP group, median 190 mW, range 100 - 950 mW, and PRP group, median 800 mW, range 100 - 2000 mW. On subgroup comparison, for similar spot size, as treatment duration decreased, the power required increased, albeit in a much lesser proportion than that given by energy = power x time. Most frequently used patterns were single spot (89% of cases) in FP, 5 × 5 box (72%) in PRP, and 2 × 2 box (78%) in BP. Spot diameters as high as ≈ 700 m on retina were given in the PRP group. Single session PRP was attempted in six eyes with a median spot count of 3500. Conclusion: Overall, due to the small duration of its pulse, the Pascal® photocoagulator tends to use higher powers, although much lower cumulative energies, than those used in a conventional laser. The consequent lesser heat dissipation, especially lateral, can allow one to use relatively larger spot sizes and give more closely spaced burns, without incurring significant side effects.
AB - Aim: To systematically refine and recommend parameter settings of spot size, power, and treatment duration using the Pascal® photocoagulator, a multi-spot, semi-automated, short-duration laser system. Materials and Methods: A retrospective consecutive series with 752 Caucasian eyes and 1242 laser procedures over two years were grouped into, (1) 374 macular focal / grid photocoagulation (FP), (2), 666 panretinal photocoagulation (PRP), and (3) 202 barrage photocoagulation (BP). Parameters for power, duration, spot number, and spot size were recorded for every group. Results: Power parameters for all groups showed a non-gaussian distribution; FP group, median 190 mW, range 100 - 950 mW, and PRP group, median 800 mW, range 100 - 2000 mW. On subgroup comparison, for similar spot size, as treatment duration decreased, the power required increased, albeit in a much lesser proportion than that given by energy = power x time. Most frequently used patterns were single spot (89% of cases) in FP, 5 × 5 box (72%) in PRP, and 2 × 2 box (78%) in BP. Spot diameters as high as ≈ 700 m on retina were given in the PRP group. Single session PRP was attempted in six eyes with a median spot count of 3500. Conclusion: Overall, due to the small duration of its pulse, the Pascal® photocoagulator tends to use higher powers, although much lower cumulative energies, than those used in a conventional laser. The consequent lesser heat dissipation, especially lateral, can allow one to use relatively larger spot sizes and give more closely spaced burns, without incurring significant side effects.
KW - Barrage photocoagulation
KW - focal photocoagulation
KW - laser power
KW - laser spot size
KW - laser treatment duration
KW - panretinal photocoagulation
KW - pascal® photocoagulation
UR - http://www.scopus.com/inward/record.url?scp=79952413340&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79952413340&partnerID=8YFLogxK
U2 - 10.4103/0301-4738.77007
DO - 10.4103/0301-4738.77007
M3 - Article
C2 - 21350276
AN - SCOPUS:79952413340
VL - 59
SP - 87
EP - 91
JO - Indian Journal of Ophthalmology
JF - Indian Journal of Ophthalmology
SN - 0301-4738
IS - 2
ER -