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Letters to the Editor
705 gluing’, the present system is readily implemented with little bottle modification. The soft plastic nature of the dispensing tips minimizes the risk of eye injury due to improper drop administration. Moreover, the 0.5-inch dispensing tip provides an extension of the drop delivery orifice such that ease in positioning the tip to just within the lower lid margin is facilitated, thus improving efficiency in drop administration.
Bruce I Gaynes PharmD Department of Ophthalmology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA Received 30 December 2013; accepted 7 January 2014.
REFERENCES Figure 1. Far left, commercial ophthalmic bottle with dispenser tip removed. Near left, screw on Luer adapter. Centre, colour-coded dispensing tips of various bore sizes with Luer lock hubs. Far right, slip on protective cover.
advantage of reduced drop volume in terms of enhanced bioavailability and reduced toxicity; however, the mechanism by which tip size was altered was complex.4 In contrast to the system suggested by Brown et al.4 that utilized modification of tips by ’cutting, lathing, drilling and
1. Lang J. Ocular drug delivery conventional ocular formulations. Adv Drug Deliv Rev 1995; 16: 39–43. 2. Olejnik O. Conventional Systems in Ophthalmic Drug Delivery. Basel, Switzerland: Marcel Dekker, 1993; 177– 98. 3. Gaynes BI, Singa RM, Cao Y. Dosage variability of topical ocular hypotensive products: a densitometric assessment. J Glaucoma 2009; 18: 149–52. 4. Brown RH, Hotchkiss ML, Davis EB. Creating smaller eye drops by reducing eyedropper tip dimensions. Am J Ophthalmol 1985; 99: 460–4.
Measured tetracaine drop volume (mean, SD) versus tip bore 40
Crystalline lens malignancy
35
Unfortunately, Ullrich and Casson1,2 and Walland and Thomas3 have missed the mark in their well-intentioned, earnest but misguided discussion about crystalline lens epithelial malignancies. As has been resoundingly demonstrated, various cell lines display a wide spectrum of malignant potential.4 There is nothing particularly surprising that epithelial cells quietly growing and happily denucleating should demonstrate an absence of malignant intent or effect. Even if such cells were to transform unnaturally, current phakoemulsification techniques do not remove them all. Akin to prostate cancer, where transurethral resection for benign prostatic hypertrophy confers no protection against subsequent malignancies,5 anything other than a complete intracapsular lens extraction should not do so either. Should lens epithelial cells have proven capable of evil, by embracing extra-capsular techniques, ophthalmologists may have forsaken their proactive responsibility to their patients. As a profession, we would seem to have much for which to be grateful.
Microlitres
30 25 20 15 10 5
er ci al Co m m
n) ro w (b m m 1.3 70
m 84 0 0.
0.
32 0
m
m
m
(p i
(g re en )
nk )
0
Figure 2. Drop volume versus internal bore diameter of dispensing tip. The increase in bore diameter is well correlated to drop volume. SD, standard deviation.
Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
706
Letters to the Editor Ivan Goldberg FRANZCO1,2,3 Glaucoma Unit, Sydney Eye Hospital, 2 Eye Associates, and 3University of Sydney, Sydney, New South Wales, Australia 1
Received 26 December 2013; accepted 7 January 2014.
REFERENCES 1. Ullrich K, Casson RJ. Does anybody care that the crystalline lens never gets cancer? Clin Experiment Ophthalmol 2013; 41: 812. 2. Ullrich K, Casson RJ. Ophthalmologists’ success in cancer prevention: response. Clin Experiment Ophthalmol 2013; 41: 816.
3. Walland MJ, Thomas R. Ophthalmologists’ success in cancer prevention. Clin Experiment Ophthalmol 2013; 41: 815–16. 4. Albini A, Iwamoto Y, Kleinman HK et al. A rapid in vitro assay for quantitating the invasive potential of tumor cells. Cancer Res 1987; 47: 3239–45. 5. Holman CDJ, Wisniewski ZS, Semmens JB, Rouse IL, Bass AJ. Mortality and prostate cancer risk in 19 598 men after surgery for benign prostatic hyperplasia. BJU Int 1999; 84: 37–42.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
Letters to the Editor
705 gluing’, the present system is readily implemented with little bottle modification. The soft plastic nature of the dispensing tips minimizes the risk of eye injury due to improper drop administration. Moreover, the 0.5-inch dispensing tip provides an extension of the drop delivery orifice such that ease in positioning the tip to just within the lower lid margin is facilitated, thus improving efficiency in drop administration.
Bruce I Gaynes PharmD Department of Ophthalmology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois, USA Received 30 December 2013; accepted 7 January 2014.
REFERENCES Figure 1. Far left, commercial ophthalmic bottle with dispenser tip removed. Near left, screw on Luer adapter. Centre, colour-coded dispensing tips of various bore sizes with Luer lock hubs. Far right, slip on protective cover.
advantage of reduced drop volume in terms of enhanced bioavailability and reduced toxicity; however, the mechanism by which tip size was altered was complex.4 In contrast to the system suggested by Brown et al.4 that utilized modification of tips by ’cutting, lathing, drilling and
1. Lang J. Ocular drug delivery conventional ocular formulations. Adv Drug Deliv Rev 1995; 16: 39–43. 2. Olejnik O. Conventional Systems in Ophthalmic Drug Delivery. Basel, Switzerland: Marcel Dekker, 1993; 177– 98. 3. Gaynes BI, Singa RM, Cao Y. Dosage variability of topical ocular hypotensive products: a densitometric assessment. J Glaucoma 2009; 18: 149–52. 4. Brown RH, Hotchkiss ML, Davis EB. Creating smaller eye drops by reducing eyedropper tip dimensions. Am J Ophthalmol 1985; 99: 460–4.
Measured tetracaine drop volume (mean, SD) versus tip bore 40
Crystalline lens malignancy
35
Unfortunately, Ullrich and Casson1,2 and Walland and Thomas3 have missed the mark in their well-intentioned, earnest but misguided discussion about crystalline lens epithelial malignancies. As has been resoundingly demonstrated, various cell lines display a wide spectrum of malignant potential.4 There is nothing particularly surprising that epithelial cells quietly growing and happily denucleating should demonstrate an absence of malignant intent or effect. Even if such cells were to transform unnaturally, current phakoemulsification techniques do not remove them all. Akin to prostate cancer, where transurethral resection for benign prostatic hypertrophy confers no protection against subsequent malignancies,5 anything other than a complete intracapsular lens extraction should not do so either. Should lens epithelial cells have proven capable of evil, by embracing extra-capsular techniques, ophthalmologists may have forsaken their proactive responsibility to their patients. As a profession, we would seem to have much for which to be grateful.
Microlitres
30 25 20 15 10 5
er ci al Co m m
n) ro w (b m m 1.3 70
m 84 0 0.
0.
32 0
m
m
m
(p i
(g re en )
nk )
0
Figure 2. Drop volume versus internal bore diameter of dispensing tip. The increase in bore diameter is well correlated to drop volume. SD, standard deviation.
Competing/conflicts of interest: No stated conflict of interest. Funding sources: No stated funding sources.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
706
Letters to the Editor Ivan Goldberg FRANZCO1,2,3 Glaucoma Unit, Sydney Eye Hospital, 2 Eye Associates, and 3University of Sydney, Sydney, New South Wales, Australia 1
Received 26 December 2013; accepted 7 January 2014.
REFERENCES 1. Ullrich K, Casson RJ. Does anybody care that the crystalline lens never gets cancer? Clin Experiment Ophthalmol 2013; 41: 812. 2. Ullrich K, Casson RJ. Ophthalmologists’ success in cancer prevention: response. Clin Experiment Ophthalmol 2013; 41: 816.
3. Walland MJ, Thomas R. Ophthalmologists’ success in cancer prevention. Clin Experiment Ophthalmol 2013; 41: 815–16. 4. Albini A, Iwamoto Y, Kleinman HK et al. A rapid in vitro assay for quantitating the invasive potential of tumor cells. Cancer Res 1987; 47: 3239–45. 5. Holman CDJ, Wisniewski ZS, Semmens JB, Rouse IL, Bass AJ. Mortality and prostate cancer risk in 19 598 men after surgery for benign prostatic hyperplasia. BJU Int 1999; 84: 37–42.
© 2014 Royal Australian and New Zealand College of Ophthalmologists
