Topical Proparacaine Eye Drops to Improve the Experience of Patients Undergoing Intravitreal Injections
Phase: NA
Conditions: Age-related Macular Degeneration, Diabetic Macular Edema, Injection Site, Injection Site Infection, Pain, Postoperative
Sponsor: Mayo Clinic

 
 
Topical Proparacaine Eye Drops 
to Improve the Experience of 
Patients Undergoing 
Intravitreal Injections 
 
NCT# 02951351 
 
September 07, 2016 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
 
INTRODUCTORY STATEMENT 
 
The specific aims of this study are to compare patient experience with and without a 
proparacaine drop after povidone iodine. To ensure the extra drop does not interfere with 
antisepsis, conjunctival cultures will be obtained from patients undergoing intravitreal injection 
before and after the application of the extra eye drop. 
A. Background information: 
1. Intravitreal injections 
Intravitreal injections are used to treat patients with many ocular conditions including: 
exudative age related macular degeneration, endophthalmitis, CMV retinitis, forms of choroidal 
neovascularization, e.g. diabetic retinopathy, and macular edema.   
2. A feared complication, endophthalmitis 
Endophthalmitis is a post-injection complication with great morbidity. A comprehensive 
review published in 2004 outlining the risk of endophthalmitis after intravitreous injection found 
a 0.2% prevalence per injection, which increased to 0.6% prevalence for injection with 
triamcinolone acetonide.  All other injected medications had a risk of 0.1% per injection.[1] A 
2011 study published in Retina reported that 1 out of every 4000 to 8000 injections of anti-VEGF 
medications results in endophthalmitis.[2] Finally, a study using a Medicare database found that 
of 41,000 injections, the rate of post-injection endophthalmitis was about 0.09% per injection.[3] 
The specific bacteria that cause post-injection endophthalmitis have been reported in a 
study by McCannel as most commonly coagulase-negative Staphylococcus species in 65.4% of 
cases where a bacterium was identified.  Streptococcus species were identified in 30.8% of 
endophthalmitis cases; most commonly viridans group streptococci (VGS), S. salivarius, and S. 
mitis. [4] 
3. Preventative measures 
To prevent endophthalmitis, sterilization is attempted before injections using 5% 
povidone-iodine (PI), Betadine, which has been demonstrated to be as effective as topical 
antibiotics. [5] Povidone iodine’s use prior to IVI is supported by a number of studies.[6, 7]  Apt 
et al. demonstrated that one drop of povidone iodine administered preoperatively reduced 
bacterial colonies in conjunctival cultures by 91% versus 33% for control eyes.[8]  Isenberg 
demonstrated that preoperative administration of povidone iodine was as effective as neomycin, 
polymyxin B, and gramicidin (Neosporin, Johnson & Johnson, New Brunswick, NJ) ophthalmic 
solution given three consecutive days prior to surgery in reducing conjunctival cultures. 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
Neosporin plus povidone iodine was more effective than either alone, leading to a 99.9% 
decreased colony count.[6]  Overall, povidone iodine is nontoxic to the eye in the appropriate 
concentrations, has a broad antimicrobial spectrum (including bacteria, fungi, protozoa, and 
viruses), has a low propensity to select for bacterial resistance, is inexpensive, and is widely 
available.[9]   
4. Antimicrobial properties of proparacaine  
The antibacterial properties of proparacaine have been previously reported.  A study on 
the effects of topical anesthetics on bacteria using a disk diffusion technique studied proparacaine 
and 0.5, 0.25, and 0.125% concentrations found that proparacaine inhibited the growth of 
Staphylococcus aureus at 1,250 µg/mL, and inhibited Pseudomonas aeruginosa growth at 2,500 
µg/mL. [10] Proparacaine has also been demonstrated to have antimicrobial properties against 
Staphylococcus epidermidis and viridans group streptococci (VGS).  It has been shown to reduce 
the number of culture-positive eyes, with 4 of 40 eyes being culture-positive after proparacaine, 
versus 12 of 36 eyes being culture-positive after receiving control solution, containing only 
preservative.[11]  The mechanism by which proparacaine acts as an antimicrobial has been 
studied; it is thought to disrupt bacterial cell membranes causing permeability and lysis.[12, 13]  
Finally, benzalkonium chloride, the preservative component of proparacaine, has been 
demonstrated to have antimicrobial effects, with an in vitro study showing that benzalkonium 
chloride inhibits S. aureus growth.[14]   
5. Background research (see attachment): 
We have previously conducted a study comparing the minimum inhibitory concentrations 
(MICs) of topical anesthetics utilized prior to intravitreal injection (proparacaine, tetracaine, 
lidocaine), preservative benzalkonium chloride, and antiseptic povidone iodine for bacteria 
causing endophthalmitis. Lidocaine (8.53x10-5mol/mL) had MICs of 4.27x10-5-8.53x10-5 mol/mL, 
and tetracaine (1.89x10-5mol/mL) had MICs of 9.45x10-6 mol/mL for all isolates. Proparacaine 
(1.7x10-5 mol/mL) had MICs of 1.32 to 5.3x10-7 mol/mL, 4.25x10-6 mol/mL for S. epidermidis, 
VGS, respectively).  Benzalkonium chloride (3.52x10-7 mol/mL) had MICs of 1.86x10-9-1.1x10-8 
mol/mL, 4.40x10-8 mol/mL for S. epidermidis, VGS, respectively.  Povidone iodine (1.37x10-4 
mol/mL) had MICs of 2.14x10-6-4.28x10-6 mol/mL, 8.56x10-6 mol/mL for S. epidermidis, VGS, 
respectively.   
Proparacaine was the anesthetic with lowest MICs, lower than that of povidone iodine.  
Benzalkonium chloride had a lower MIC than proparacaine. All tested topical anesthetics and 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
povidone iodine inhibited growth of S. epidermidis and VGS at commercially available 
concentrations.   
We also previously studied synergy and antagonism for all isolates using povidone iodine 
at 25% and 50% of its MIC.  Proparacaine with povidone iodine demonstrated synergy against all 
VGS studied and additivity or indifference against all strains of S. epidermidis. Benzalkonium 
chloride with povidone iodine demonstrated synergy against 80% of S. epidermidis isolates 
studied and additivity or indifference against all VGS.    
6. Significance  
Intravitreal injections are one of the most common procedures performed by 
ophthalmologists.  As its indications expand and the population with conditions treated with 
intravitreal injections grows, it is beneficial to know how to prevent complications such as 
endophthalmitis.  It is often the case that patients will have a painful injection and refuse 
additional vision-saving treatment.  A study to compare the timing of eye drops could help 
improve patient experience.  It will also be important to compare conjunctival cultures of patients 
treated with proparacaine alone and with povidone iodine may be informative from an 
antimicrobial standpoint.   
From the perspective of patient experience, recent studies have demonstrated great 
patient dissatisfaction with the application of povidone iodine.  In a study by van Asten et al., 
more patients (26%) reported povidone iodine application than intravitreal injection (10%) to be 
the most bothersome part of the intravitreal injection process. [15] The current expert guidelines 
for IVI stress the importance of 5.0% povidone iodine use.  The guidelines recommend that 
povidone iodine should be the last agent applied before performing injections, and physicians 
should be careful as the anesthetic may interfere with the contact of povidone iodine to the 
conjunctival surface.  Therefore, the guidelines recommend applying povidone iodine before and 
after topical anesthetic.  It is possible, though, that the antimicrobial effects of proparacaine allow 
it to be applied following the povidone iodine in patients who find PI unpleasant.  
It would also be useful to determine the impact of proparacaine and povidone iodine on 
each other.  In our preliminary studies, proparacaine with povidone iodine demonstrated synergy 
against all VGS studied.  Benzalkonium chloride with povidone iodine demonstrated synergy 
against 80% of S. epidermidis isolates studied.  These results may influence choice of topical 
anesthetic.  
 
 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
Proparacaine 
(http://www.micromedexsolutions.com/micromedex2/librarian/PFDefaultActionId/eviden
cexpert.DoIntegratedSearch#)  is a topical anesthetic commonly used prior to 
intravitreal injections. This proposal recommends deviating from the usual protocol of 
one drop of proparacaine prior to povidone iodine to adding an addition drop of 
proparacaine after the povidone iodine as proparacaine has been demonstrated to have 
antimicrobial properties and assist with patient comfort.  
 
GENERAL INVESTIGATIONAL PLAN 
 
Study rationale- Intravitreal injections are one of the most common procedures performed 
by ophthalmologists. The study endpoints are to improve the patient experience while minimizing 
negative outcomes, one of the most worrisome of these outcomes is endophthalmitis.  The study 
will address first patient experience and ensure that the treatment is not detrimental to antisepsis.  
Indication- To compare the effects of proparacaine before and after povidone iodine 
application on patient experience, and to compare bacterial colonies in conjunctival cultures 
obtained from patients undergoing intravitreal injection to ensure adequate antisepsis.  
General approach/Treatment plan (See figure 1)- The study will take place during 
intravitreal injections.  The anticipated study is as follows: After a procedural time out to 
verify patient, agent, and laterality, proparacaine will be applied to the ocular surface.  A 
conjunctival culture will then be obtained followed by the application of povidone-iodine 
to the eyelashes and eyelid margins.  The eyelids will then be retracted away from the 
intended injection site for the duration of the procedure.  At this point, half of the patients 
will be randomized to receive 5% povidone-iodine drop to the conjunctival surface 
followed by conjunctival culture then re-application of 5% povidone-iodine drop to the 
conjunctival surface. A needle will then be inserted perpendicular to the sclera, 3.5-4.0 
mm posterior to the limbus between the vertical and horizontal rectus muscles.  The other 
half of patients will undergo application of another drop of topical anesthetic followed by 
conjunctival culture.  After the culture, this group of patients will have 5% povidone 
iodine applied to the conjunctival surface. A needle will then be inserted perpendicular to 
the sclera, 3.5-4.0 mm posterior to the limbus between the vertical and horizontal rectus 
muscles. 
 
 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
Figure 1 
** the circles highlight deviations from the typical protocol 
Human subjects  
Sixty patients (male and female) undergoing intravitreal injection who do not have active eye 
infections will be enrolled after undergoing informed consent.   
Exclusion criteria: 1. Age less than 18. 2. Patients with active eye infections 
The main risk encountered by human subjects would be infection given extra manipulation 
prior to intravitreal injection.  These risks will be minimized by using sterile culture techniques.  
All cultures will be followed by application of povidone iodine to comply with current 
recommendations to sterilize conjunctiva prior to intravitreal injection.  It is also possible that 
patients will experience increased discomfort due to the conjunctival cultures.  Per the protocol, 
cultures will follow topical anesthetic application.  
Data collection: 
Conjunctival cultures will be incorporated into the current intravitreal injection procedure 
Take a procedural time-out to verify patient, agent, and laterality 
Apply liquid anesthetic drops to the ocular surface 
Culture patient conjunctiva 
Apply povidone–iodine to the eyelashes and eyelid margins 
Retract the eyelids away from the intended injection site for the duration 
of the procedure 
1/2 of patients: Apply 5% povidone–iodine to the 
conjunctival surface, including the intended injection 
site 
conjunctival culture 
Apply 5% povidone–iodine to the conjunctival 
surface, including the intended injection site, at least 
30 seconds before injection 
Insert the needle perpendicular to the sclera, 
3.5 to 4.0 mm posterior to the limbus 
between the vertical and horizontal rectus 
muscles. 
1/2 of patients: Apply another drop of 
topical anesthetic 
conjuntival culture 
Apply 5% povidone–iodine to the conjunctival 
surface, including the intended injection site, at 
least 30 seconds before injection 
Insert the needle perpendicular to the sclera, 3.5 
to 4.0 mm posterior to the limbus between the 
vertical and horizontal rectus muscles. 
patients are randomized 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
followed by Mayo Clinic.: 
 
a. Conjunctival cultures  
Bacterial cultures will be performed from conjunctival samples.  Bacterial speciation will be 
performed on any bacteria that grows using the usual procedure to determine the bacterial species 
collected by the study.  
  
b. Proparacaine Eye drops  
Proparacaine 0.5% with preservative benzalkonium chloride 0.01% (Akorn) will be analyzed for 
its effect on bacterial growth in vivo with and without povidone iodine.  
c. Data analysis and interpretation 
Whether cultures are positive or negative will be compared between groups.  Outcomes will also 
be measured by comparing the semiquantitative number of bacterial cultures (the microbiology 
lab will report cultures as 1+ through 4+) according to the Mayo Clinic Microbiology laboratory 
protocol.  Patients who have positive cultures will have specific bacterial species determined 
which will also be analyzed. Demographic characteristics will be recorded including date of 
Take a procedural time-out to verify patient, agent, and laterality 
Apply liquid anesthetic drops to the ocular surface 
Culture patient conjunctiva 
Apply povidone–iodine to the eyelashes and eyelid margins 
Retract the eyelids away from the intended injection site for the duration 
of the procedure 
1/2 of patients: Apply 5% povidone–iodine to the 
conjunctival surface, including the intended injection 
site 
conjunctival culture 
Apply 5% povidone–iodine to the conjunctival 
surface, including the intended injection site, at least 
30 seconds before injection 
Insert the needle perpendicular to the sclera, 
3.5 to 4.0 mm posterior to the limbus 
between the vertical and horizontal rectus 
muscles. 
1/2 of patients: Apply another drop of 
topical anesthetic 
conjuntival culture 
Apply 5% povidone–iodine to the conjunctival 
surface, including the intended injection site, at 
least 30 seconds before injection 
Insert the needle perpendicular to the sclera, 3.5 
to 4.0 mm posterior to the limbus between the 
vertical and horizontal rectus muscles. 
patients are randomized 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
birth and sex. Information surrounding the indication for injection will also be obtained 
as well as type of medication injected and number of previous injections. Finally, 
medication data will be included with specific focus on antibiotics—topical or systemic 
and eye drops.  
In addition, patients will complete the previously detailed survey regarding their 
experience. Patient experience will be compared between groups and to existing data 
from this previously utilized survey described in PMID: 25901838. 
Human subjects  
Sixty patients (male and female) undergoing intravitreal injection who do not have active eye 
infections will be enrolled after undergoing informed consent.   
Exclusion criteria: 1. Age less than 18. 2. Patients with active eye infections 
The main risk encountered by human subjects would be infection given extra manipulation 
prior to intravitreal injection.  These risks will be minimized by using sterile culture techniques.  
All cultures will be followed by application of povidone iodine to comply with current 
recommendations to sterilize conjunctiva prior to intravitreal injection.  It is also possible that 
patients will experience increased discomfort due to the conjunctival cultures.  Per the protocol, 
cultures will follow topical anesthetic application.  
Treatment plan: 
After a procedural time out to verify patient, agent, and laterality, proparacaine will be 
applied to the ocular surface.  A conjunctival culture will then be obtained followed by 
the application of povidone-iodine to the eyelashes and eyelid margins.  The eyelids will 
then be retracted away from the intended injection site for the duration of the procedure.  
At this point, half of the patients will be randomized to receive 5% povidone-iodine drop 
to the conjunctival surface followed by conjunctival culture then re-application of 5% 
povidone-iodine drop to the conjunctival surface. A needle will then be inserted 
perpendicular to the sclera, 3.5-4.0 mm posterior to the limbus between the vertical and 
horizontal rectus muscles.  The other half of patients will undergo application of another 
drop of topical anesthetic followed by conjunctival culture.  After the culture, this group 
of patients will have 5% povidone iodine applied to the conjunctival surface. A needle 
will then be inserted perpendicular to the sclera, 3.5-4.0 mm posterior to the limbus 
between the vertical and horizontal rectus muscles.   

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
Safety 
The current protocol for intravitreal injections requires that patients be treated with 
povidone iodine immediately prior to intravitreal injection for antisepsis.  The protocol 
for this study will not deviate from the standard protocol in that way.  The safety of the 
study will be monitored by the PI. If more than 4 patients are noted post-procedurally to 
require additional return visits for conjunctival irritation or infection, the study will be 
discontinued. 
1. Leavitt JA, Singer W, Brown WL, Pulido JS, Brodsky MC.  Retinal and Pontine 
Striations: Neurodiagnostic Signs of Autosomal Recessive Spastic Ataxia of 
Charlevoix-Saguenay.  J Neuroophthalmol. 2014 Sep 18. [Epub ahead of print]. 
 
2. Gardner FP, Serie DJ, Salomao DR, Wu KJ, Markovic SN, Pulido JS, Joseph 
RW.  c-MET expression in primary and liver metastases in uveal melanoma.  
Melanoma Res. 2014 Sep 10. [Epub ahead of print] 
 
3. Turan KE, Pulido JS, Brodsky MC.  Incipient white dot fovea syndrome in a 
child.  J AAPOS. 2014 Aug;18(4):391-3. doi: 10.1016/j.jaapos.2014.02.007. Epub 2014 Jun 7. 
 
4. Liu CY, Francis JH, Brodie SE, Marr B, Pulido JS, Marmor MF, Abramson DH. 
Retinal toxicities of cancer therapy drugs: biologics, small molecule inhibitors, 
and chemotherapies.  Retina. 2014 Jul;34(7):1261-80. doi: 10.1097/IAE.0000000000000242. 
 
5. Alonso-Camino V, Rajani K, Kottke T, Rommelfanger-Konkol D, Zaidi S, 
Thompson J, Pulido J, Ilett E, Donnelly O, Selby P, Pandha H, Melcher A, 
Harrington K, Diaz RM, Vile R.  The Profile of Tumor Antigens Which Can be 
Targeted by Immunotherapy Depends Upon the Tumor's Anatomical Site.  Mol 
Ther. 2014 Jul 25. doi: 10.1038/mt.2014.134. [Epub ahead of print] 
 
6. Mansour AM, Arevalo JF, Al Kahtani E, Zegarra H, Abboud E, Anand R, 
Ahmadieh H, Sisk RA, Mirza S, Tuncer S, Navea Tejerina A, Mataix J, Ascaso 
FJ, Pulido JS, Guthoff R, Goebel W, Roh YJ, Banker AS, Gentile RC, Martinez 
IA, Morris R, Panday N, Min PJ, Mercé E, Lai TY, Massoud V, Ghazi NG.  Role 
of Intravitreal Antivascular Endothelial Growth Factor Injections for Choroidal 
Neovascularization due to Choroidal Osteoma.J Ophthalmol. 2014;2014:210458. doi: 
10.1155/2014/210458. Epub 2014 Jul 23. 
 
7. Wang J, Pulido JS, O'Neill BP, Johnston PB.  Second malignancies in patients 
with primary central nervous system lymphoma.Neuro Oncol. 2014 Jun 19. pii: nou105. 
[Epub ahead of print] 
 
8. Mansour AM, Arevalo JF, Badal J, Moorthy RS, Shah GK, Zegarra H, Pulido JS, 
Charbaji A, Amselem L, Lavaque AJ, Casella A, Ahmad B, Paschall JG, Caimi 
A, Staurenghi G. Paraproteinemic Maculopathy.Ophthalmology. 2014 Jun 17. pii: S0161-
6420(14)00343-1. doi: 10.1016/j.ophtha.2014.04.007. [Epub ahead of print] 
 

 
Protocol IRB#16-004063 
 
STUDY NAME 
 
9. Caraballo JN, Snyder MR, Johnston PB, O Neill BP, Raja H, Balsanek JG, Peters 
BE, Pulido JS.  Vitreoretinal lymphoma versus uveitis: cytokine profile and 
correlations. Ocul Immunol Inflamm. 2014 Feb;22(1):34-41. doi: 10.3109/09273948.2012.752507. 
 
10. Kottke T, Boisgerault N, Diaz RM, Donnelly O, Rommelfanger-Konkol D, Pulido J, Thompson J, 
Mukhopadhyay D, Kaspar R, Coffey M, Pandha H, Melcher A, Harrington K, Selby P, Vile R. 
Detecting and targeting tumor relapse by its resistance to innate effectors at early recurrence.  Nat 
Med. 2013 Dec;19(12):1625-31. doi: 10.1038/nm.3397. Epub 2013 Nov 17. 
 
11. Pulido JS, Flotte TJ, Raja H, Miles S, Winters JL, Niles R, Jaben EA, Markovic SN, Davies J, 
Kalli KR, Vile RG, Garcia JJ, Salomao DR. Dermal and conjunctival melanocytic proliferations in 
diffuse uveal melanocytic proliferation.  Eye (Lond). 2013 Sep;27(9):1058-62. doi: 
10.1038/eye.2013.131. Epub 2013 Jun 21. 
 
12. Boisgerault N, Kottke T, Pulido J, Thompson J, Diaz RM, Rommelfanger-Konkol D, Embry A, 
Saenz D, Poeschla E, Pandha H, Harrington K, Melcher A, Selby P, Vile R. Functional cloning of 
recurrence-specific antigens identifies molecular targets to treat tumor relapse. Mol Ther. 2013 
Aug;21(8):1507-16. doi: 10.1038/mt.2013.116. Epub 2013 Jun 11. 
 
13. Donnelly OG, Melcher AA, Vile RG, Pulido J. What new immunotherapeutic techniques are 
currently being investigated for the treatment of melanoma?  Immunotherapy. 2012 Aug;4(8):749-
51. doi: 10.2217/imt.12.65. No abstract available.