4. Chung JL, Seo KY, Yong DE, et al. Antibiotic susceptibility ofconjunctival bacterial isolates from refractive surgery patients.Ophthalmology 2009;116(6):1067–1074.

5. Blanco AR, Sudano Roccaro A, Spoto CG, Papa V. Suscepti-bility of methicillin-resistant staphylococci clinical isolates tonetilmicin and other antibiotics commonly used in ophthalmictherapy. Curr Eye Res (forthcoming).

6. Yagupsky P. Selection of antibiotic-resistant pathogensin the community. Pediatr Infect Dis J 2006;25(10):974–976.

REPLY

WE APPRECIATE THE INTEREST OF GALVIS ANDASSOCIATES

in our study.1 We additionally applaud them for doinga surveillance of the local bacterial pathogens encounteredin their geographic area. The authors point out the resultsof the ESCRS endophthalmitis study, which supports theusage of intracameral cefuroxime for peri–cataract surgeryprophylaxis instead of topical antibiotics application.2

Additionally, we would like to point out a more recentreport from Northern California that additionally supportsthe use of intracameral antibiotics.3 However, our originalstudy is intended to only evaluate the ocular flora andtheir antibiotic susceptibility patterns in the Saint Louiscommunity and not to deeply discuss the pros and cons ofvarious methods of endophthalmitis prophylaxis. A discus-sion of endophthalmitis prophylaxis is likewise beyond thescope of the current correspondence.

The authors correctly point out that the results of ourstudy more closely match those from other investigatorsin the United States and differ more significantly withresults from other parts of the world, including their insti-tution. The authors emphasize that in other parts of theworld, staphylococcal resistance to aminoglycosides(specifically tobramycin) is markedly higher than whatwe encounter in Saint Louis. Whereas the resistance rateof gram-positive organisms to aminoglycosides (genta-micin) is 5% in Saint Louis, it is 85% (to tobramycin) inColombia. As a result, the authors voice their concernregarding our recommendation to cataract surgeons toconsider aminoglycosides for perioperative prophylaxis.

Throughout our original publication, we emphasizeseveral times that readers should extrapolate our findingswith caution as antibiotic resistance rates vary overgeographic areas as well as over time. As a result, surgeonsshould investigate and be aware of their local antibioticsusceptibility patterns. Again, we applaud the authors forhaving done just that at their institutions. Implicit in therecommendation and concluding statements from ourpublication is that they are intended for ophthalmologistsin the Saint Louis area as well as other communitiesthat share similar antibiotic susceptibility patterns—specifically, those areas that have high and growingfluoroquinolone resistance rates and relatively low levels

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of aminoglycoside resistance. Nonetheless, we appreciatethe authors for pointing out the need for clarification.Additionally, we would like to clarify and stress an impliedpoint made by the authors: Although aminoglycosides maybe a poor choice at their institutions and other parts of theworld where resistance rates are high, surgeons in parts ofthe world where aminoglycosides retain a favorable resis-tance pattern should not be dissuaded from utilizing thisclass of antibiotics.

HUGO Y. HSU

Los Angeles, CaliforniaJOHN T. LIND

Saint Louis, Missouri

CONFLICT OF INTEREST DISCLOSURES: SEE THE ORIGINALarticle1 for any disclosures of the authors.

REFERENCES

1. Hsu HY, Lind JT, Tseng L, Miller D. Ocular flora and theirantibiotic resistance patterns in the midwest: a prospectivestudy of patients undergoing cataract surgery. Am J Ophthalmol2013;155(1):36–44.

2. ESCRS Endophthalmitis Study Group. Prophylaxis of postop-erative endophthalmitis following cataract surgery: Results ofthe ESCRS multicenter study and identification of risk factors.J Cataract Refract Surg 2007;33(6):978–988.

3. Shorstein NH,Winthrop KL, Herrinton LJ. Decreased postop-erative endophthalmitis rate after institution of intracameralantibiotics in a Northern California eye department. J CataractRefract Surg 2013;39(1):8–14.

Short-Term External Buckling WithPneumatic Retinopexy for RetinalDetachment With Inferior RetinalBreaks

EDITOR:

THE STUDY BY CHENG AND ASSOCIATES ONE SHORT-TERM

external buckling with pneumatic retinopexy treatingretinal detachment with inferior retinal breaks givesus new insight.1 Rhegmatogenous retinal detachment(RRD) with inferior breaks usually is a contraindicationfor pneumatic retinopexy.2 Although the authors chal-lenged this restricted area and obtained good results (therate of successful retinal reattachment within 6 monthswas 87.9%), as some other vitreoretinal specialists did,3–5

the vitreous traction may persist after the removal of theexternal buckle and gas being absorbed. Does this meanvitreous traction is not an important issue for retinalreattachment, and intraoperative transconjunctivalcryopexy and supplementary laser photocoagulationapplied around the retinal breaks combined with

SEPTEMBER 2013OPHTHALMOLOGY

chorioretinal adhesive force are enough for long-termeffects in most cases of primary RRD? As a result, furtherobservation could be added to verify the hypothesis.Vitreous traction could be observed by some means suchas optical coherence tomography through the entirefollow-up period. Does vitreous traction persist, or is itreleased because of vitreous liquefaction, after cryopexyand laser photocoagulation?

In addition, is pneumatic retinopexy really needed?Pneumatic retinopexy often has been used for primaryRRD surgery with superior breaks (a break located betweenthe 8-o’clock and 4-o’clock positions), but seldom has beenrecommended for those with inferior breaks because thesurface tension of gas is weakened for closing the inferiorretinal breaks as a result of the position in the eyeball.More-over, it could cause some complications such as large intra-ocular pressure rise, cataract, new retinal breaks, and soforth.6 If short-term external buckling is enough for retinalreattachment, an invasive procedure could be avoided.

We hope the authors offer more convincing evidence inthe future. If vitreous traction is not important and pneu-matic retinopexy is not needed, RRD surgery would besimplified, which would be a real innovation for RRDsurgery. A conjunctival incision no longer would be neededand the primary RRD surgery would become a minimallyinvasive external eye surgery. It would be enjoyed notonly by surgeons, but also by patients.

JIANHE XIAO

Jinan, ChinaCAIHUI JIANG

Beijing, ChinaHUA JIANG

Jinan, China

CONFLICT OF INTEREST DISCLOSURES: ALL AUTHORShave completed and submitted the ICMJE Form for Disclosure of PotentialConflicts of Interest and none were reported.

REFERENCES

1. Cheng HC, Lee SM, Lee FL, Liu JH, Kuan CH, Lin PK. Short-term external buckling with pneumatic retinopexy for retinaldetachment with inferior retinal breaks. Am J Ophthalmol2013;155(4):750–756.

2. Hilton GF, Das T, Majji AB, Jalali S. Pneumatic retinopexy:principles and practice. Indian J Ophthalmol 1996;44(3):131–143.

3. Hwang JF, Chen SN, Lin CJ. Treatment of inferior rhegmatog-enous retinal detachment by pneumatic retinopexy technique.Retina 2011;31(2):257–261.

4. Mansour AM. Pneumatic retinopexy for inferior retinal breaks.Ophthalmology 2005;112(10):1771–1776.

5. Chang TS, Pelzek CD, Nguyen RL, Purohit SS, Scott GR,Hay D. Inverted pneumatic retinopexy: a method of treatingretinal detachments associated with inferior retinal breaks.Ophthalmology 2003;110(3):589–594.

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6. Hilton GF, Tornambe PE, Brinton DA, et al. The complica-tion of pneumatic retinopexy. Trans Am Ophthalmol Soc1990;88:191–207; discussion 207–210.

REPLY

WE HAD PROPOSED THE SHORT-TERM EXTERNAL BUCKLING

with pneumatic retinopexy as a novel and effective treat-ment for rhegmatogenous retinal detachment (RRD)with inferior retinal breaks, with a comparable successrate to other treatment methods.1

Xiao and associates had questioned the role of vitreoustraction and the need for pneumatic retinopexy for thesepatients. Surely vitreous traction is an important and majorcausative factor of RRD. The concern about the possiblypersistent vitreous traction after the removal of theexternal buckle had also been mentioned in our study.Will vitreous traction be released after pneumatic reti-

nopexy? Will it be further lessened after external buckling,though transient in our study?Lincoff and associates reported that the cortical vitreous

of the normal cynomolgus monkey eyes appeared to bea lamellar structure composed of sheets of collagen mesh.But in the perfluorocarbon gas–treated eyes, there wasshrinking and tearing of the lamellae.2 Hikichi and associ-ates reported, in eyes with retinopathy of prematurity(ROP) that underwent retinal cryopexy and/or photocoag-ulation, that the extensive vitreous liquefaction thataffected a large segment of the vitreous was present in allthe eyes.3 It was also reported that intraocular gas injection,such as intravitreal injection of perfluoropropane gas(C3F8) in our study, may result in vitreous dissection andenhance posterior vitreous detachment during the daysimmediately after gas injection, which had been shownon optical coherence tomography (OCT).4,5

From the clinical observation, most of the vitreous trac-tion was released after the processing in our study; however,we did not have OCT results for proof currently. Actually,it is still difficult to perform an OCT investigation for farperipheral vitreoretina. The vitreous conformation is alsodifficult to describe without vitreous window enhancementby commercially available OCT. Thus, we suggested thatthe patients should be followed up closely during thecritical period between the removal of the buckle andthe formation of stable chorioretinal adhesion for theuncertainty.Though it is known that the buckle itself can provoke

reabsorption of subretinal fluid in RRD, the role of intraoc-ular gas injection is essential. As mentioned in our study,gas provides a further tamponading force from inside andhelps to seal the breaks.4 The contact surface betweengas and retina may be increased with the aid of the externalbuckling and the face-down position with 5 to 10 degrees ofneck flexion.1 Transconjunctival cryopexy and laserretinopexy were also important to provide a secure

625DENCE