Addition Of D-Sorbitol Improves The Usability Of Ophthalmic Viscosurgical Devices

Figures & data

Table 1 Investigational OVDs

OVD	Manufacturer Or Distributor	Volume (mL)	Content					Classification^Citation1,Citation20
			Hyaluronic Acid^Citation20		Chondroitin Sulfate^Citation20		D-Sorbitol
			%	Mw (kDa)	%	Mw (kDa)	%
Opegan	Santen (Japan)	0.6	1	1100	−	−	−	Very low viscos dispersive
Viscoat	Alcon (Switzerland)	0.5	3	700	4	20	−	Medium viscos dispersive
Shellgan	Santen (Japan)	0.5	3	700	4	50	0.5	Medium viscos dispersive
Discovisc	Alcon (Switzerland)	1.1	1.65	1600	4	20	-	Viscos dispersive
HA/CS-A	Homemade	0.5	3	700	4	50	−	−
HA/CS-B	Homemade	0.5	3	700	4	50	0.5	−
HA/CS-C	Homemade	0.5	3	700	4	50	1.0	−

Abbreviations: OVD, ophthalmic viscosurgical devices; Mw, molecular weight; HA, hyaluronic acid; CS, chondroitin sulfate.

Figure 1 Instruments that evaluate the extrusion force of OVDs.

Notes: (A) Texture analyzer and (B) pinch sensor.

Abbreviation: OVD, ophthalmic viscosurgical devices.

Figure 2 The survey on OVD needle clogging. A1: Answer to the Q1 “During cataract surgery or vitreous surgery, when applying viscoelastic agent to the corneal surface, have you experienced needle clogging with storage of OVDs?”

; I do not store OVDs but have experienced needle clogging,

; I have experienced needle clogging due to storage,

; I sometimes store OVDs but have not experienced needle clogging, □; I have not experienced needle clogging because I do not store OVDs. A2: Answer to the Q2 “During cataract surgery or vitreous surgery, when applying viscoelastic agent to the corneal surface, how do you deal with needle clogging?”

; Immersed the needle tip in physiological saline,

; Immersed the needle tip in BSS,

; Others.

Abbreviations: OVD, ophthalmic viscosurgical devices; BSS, balanced salt solution.

Figure 3 Dependence of the extrusion force on the storage time of OVDs with different concentrations of D-sorbitol as measured by a texture analyzer. Effect of D-sorbitol addition on the extrusion force of OVD samples containing 3% HA and 4% CS with no D-sorbitol (A), 0.5% D-sorbitol (B), or 1.0% D-sorbitol (C). Effect of open-air exposure time on the extrusion force of OVDs (D):

; no D-sorbitol,

; 0.5% D-sorbitol, and

; 1.0% D-sorbitol. The relative extrusion force (%) is presented as the mean ± standard deviation (n = 3). Effect of soaking the needle in PBS on the extrusion force of HA/CS-A exposed to the open air for 60 mins (E). Treatment: the needle tip was soaked in PBS after exposure to the open air for 60 mins. Non-treatment: the needle tip was not soaked in PBS. The relative extrusion force (%) is presented as the mean ± standard deviation (n = 5).

Abbreviations: OVD, ophthalmic viscosurgical devices; HA, hyaluronic acid; CS, chondroitin sulfate; kgf, kilogram-force; PBS, phosphate-buffered saline.

Table 2 Extrusion Forces-p Dependence On Exposure Time Of The HA/CS-A Measured By Pinch Sensor

		Initial	30 mins	60 mins	120 mins	Pinch Strength (kgf)
Men (age: 34.6 ± 5.0)	Extrusion force-p (kgf)	1.8 ± 0.2	3.4 ±1.0	4.5 ± 1.8	5.0 ± 0.4	10.4 ± 1.8
	Score	–	1.8 ± 0.8	2.8 ± 0.8	3.2 ± 0.5
Women (age: 34.6 ± 10.1)	Extrusion force-p (kgf)	1.5 ± 0.4	2.5 ± 1.5	3.4 ± 1.0	3.9 ± 0.4	7.0 ± 1.3
	Score	–	1.6 ± 0.9	3.2 ± 1.1	3.6 ± 0.6

Notes: Score: 1) No difference from the initial extrusion. 2) Felt more resistance compared to the initial extrusion, but the viscoelastic agent could be extruded without effort. 3) Felt considerably more resistance compared to the initial extrusion; it was difficult to discharge the viscoelastic agent but eventually the entire volume was released. 4) When pushed, the viscoelastic agent was not discharged at all.

Abbreviations: HA, hyaluronic acid; CS, chondroitin sulfate.

Table 3 Extrusion Forces After Storing OVDs For 30 Mins

OVD	Classification^Citation1,Citation20	Initial (kgf)	30 mins (kgf)
Opegan	Very low viscos dispersive	1.51±0.090	4.16±1.451
Viscoat	Medium viscos dispersive	1.86±0.013	4.61±0.830
Shellgan	Medium viscos dispersive	2.36±0.003	2.35±0.067
Discovisc	Viscos dispersive	2.37±0.023	3.18±0.831

Abbreviations: OVD, ophthalmic viscosurgical devices; kgf, kilogram-force.

Arshinoff SA, Jafari M. New classification of ophthalmic viscosurgical devices – 2005. J Cataract Refract Surg. 2005;31(11):2167–2171. doi:10.1016/j.jcrs.2005.08.056

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