290
Indian Journal of Ophthalmology
Mehdi Modarres, Asgari Rezanejad, Khalil Ghasemi Falavarjani
acetonide injection at the end of phacoemulsification surgery. Indian J Ophthalmol 2014;62:861‑4. 2. Jabs DA, Nussenblatt RB, Rosenbaum JT, Standardization of Uveitis Nomenclature (SUN) Working Group. Standardization of Uveitis Nomenclature for reporting clinical data. Results of the First International Workshop. Am J Ophthalmol 2005;140:509‑16. 3. Karalezli A, Borazan M, Akova YA. Intracameral triamcinolone acetonide to control postoperative inflammation following cataract surgery with phacoemulsification. Acta Ophthalmol 2008;86:183‑7. Access this article online Quick Response Code: Website: www.ijo.in
Vol. 63 No. 3
Department of Ophthalmology, Eye Research Center, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran Correspondence to: Dr. Khalil Ghasemi Falavarjani, Eye Research Center, Rassoul Akram Hospital, Sattarkhan‑Niayesh Street, Tehran 14455 ‑ 364, Iran. E‑mail: [email protected]
References 1. Modarres M, Rezanejad A, Falavarjani KG. Recurrence and massive extraocular extension of choroidal malignant melanoma after vitrectomy and endoresection. Indian J Ophthalmol 2014;62:731‑3. 2. Rice JC, Stannard C, Cook C, Lecuona K, Myer L, Scholtz RP. Brachytherapy and endoresection for choroidal melanoma: A cohort study. Br J Ophthalmol 2014;98:86‑91. 3. Kertes PJ, Johnson JC, Peyman GA. Internal resection of posterior uveal melanomas. Br J Ophthalmol 1998;82:1147‑53.
Respond to: Safe endoresection Dear Sir, We thank Dr. Seider and Damato for critically reviewing our recent paper.[1] Apparently, they have some misunderstanding about the management of our patient. We hereby elucidate further. The patient had previously been managed in another center and the information we presented about her initial management 11 years ago was extracted from her old file in that center, which unfortunately was not adequate. All the information we could obtain was that the tumor has been 15 disc diameters in size, located in nasal quadrant, and associated with exudative retinal detachment. Enucleation had been suggested to her, but she refused. Therefore, endoresection was performed as one of the few available options. We would have recommended brachytherapy in addition to endoresection had we been in charge of this patient then. We do not know whether this option was suggested at that time, but it was not performed anyway. Reportedly, she was followed for 5 years, free of recurrence, and then was lost to follow‑up. We first examined the patient a few months ago when she referred with huge enlargement of the eye with multiple protruding dark brown masses as described in our paper, and she was immediately referred for orbital exenteration after detailed explanation of the situation. Even then, she accepted the treatment after a 2 months delay.
Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156959 PMID: ***
Role of part muscle vertical rectus transposition following periosteal fixation of the lateral rectus in exotropic Duane’s retraction syndrome Dear Sir, We read with interest the article by Sharma et al.[1] Since Duane’s retraction syndrome (DRS) is not garden variety strabismus, certain observations are in order. DRS can only be alleviated, not eliminated.
We agree that endoresection is an acceptable modality of treatment for tumors up to 18 mm in basal diameter, especially when in close proximity to optic disc and macula.[2,3] However, this patient’s eye has had an entirely different picture and was not suitable for endoresection. The surgery was performed out of obligation due to her refusal of enucleation.
In exo DRS, abnormal with subnormal lateral rectus (LR) along with occasionally subnormal medial rectus (MR) innervation may occur. MR may be stretched out/elongated. Globe retraction and shoots may disappear in large Exo DRS, and both horizontals may be stiff in relatively immobile globes with marked limitation of adduction and abduction. Muscle function tests are core to DRS evaluation but find fleeting reference here. Needless to say that each case is unique and graded procedures are in order rather than un‑titrated ones, as has happened here. Control group is lacking, inferences like efficacy may not stand scrutiny of statistical analysis.
The aim of presentation of this patient was not to point out the dangers of a properly performed endoresection, but to report the unfortunate consequences of a large melanoma for which endoresection was performed as the only available option in a patient who refused enucleation and did not comply with a regular follow‑up schedule.
Cohort is too diverse as both unilateral/bilateral cases have been included. Fixating eye in unilateral cases and whether bilateral cases are fusing or nonfusing DRS is not known. Fixation duress and deviation with either eye fixing are not known. Deviations in forced primary, abnormal head posture ( AHP) and shoots are not quantified, but inferences
March 2015
291
Letters to the Editor
are drawn. Type II DRS has only adduction limitation with normal abduction, authors are likely referring to type III DRS. Primary concerns in DRS are AHP, primary position (PP) deviation, globe retraction/narrowing of the palpebral fissure in adduction, shoots, A/V patterns, fixation duress, and decentration of binocular visual fields. Improvement in ductions/binocular visual fields is secondary as patients often suppress and do not complain of diplopia in side gazes. Lateral rectus periosteal fixation converts DRS into total 6th nerve palsy with attendant muscle sequaele. For aforesaid reasons, 33% patients (2 out of 6) developed an esotropia with rest having residual XT of 6 PD or greater. Authors have to throw some light as to how abduction improved in Group 1. In fact, it should worsen which is also evident in Fig. 1. In Group 2, most cases had undercorrected exotropia in PP, implying that ½ muscle vertical rectus transposition (VRT) adds to PP exotropia and may not have been indicated. Relearning of muscle function does not happen after transposition surgery as 3rd nerve nucleus is in the midbrain and 6th nerve nucleus in the pons, postulated innervational plasticity cannot occur.[2] Following VRT in LR palsy, vertical rectus muscles do not recruit in abduction and change in direction of vector forces was minimal.[3,4] Fig. 2 does not demonstrate improved abduction. Abducting force is generated in PP and improvement in abduction could only be due to relaxation of MR. VRT has been used in eso DRS with minimal abnormal LR innervation.[5] The claims of better abduction in Group 2 as compared to Group 1 are not supported by tests of statistical significance. Adduction improvement was not full in both groups implying that part of the problem lay with MR, which cannot be operated now, and surgery on the other eye is the only option. Under the circumstances, graded options other than periosteal fixation seem to be better.
Pramod Kumar Pandey, Vishaal Bhambhwani, Shagun Sood, Kartik Rana, Poonam Gupta, PC Ranjith Department of Ophthalmology, Guru Nanak Eye Centre and Maulana Azad Medical College, New Delhi, India Correspondence to: Dr. Pramod Kumar Pandey, Room No. 201, Guru Nanak Eye Centre, Maharaja Ranjit Singh Marg, New Delhi ‑ 110 002, India. E-mail: [email protected]
References 1. Sharma P, Tomar R, Menon V, Saxena R, Sharma A. Evaluation of periosteal fixation of lateral rectus and partial VRT for cases of exotropic Duane’s retraction syndrome. Indian J Ophthalmol 2014;62:204. 2. Metz HS, Scott AB. Innervational plasticity of the oculomotor system. Arch Ophthalmol 1970;84:86‑91. 3. Metz HS, Jampolsky A. Change in saccadic velocity following rectus muscle transposition. J Pediatr Ophthalmol Strabismus 1974;11:129. 4. Scott AB. Active force tests in lateral rectus paralysis. Arch Ophthalmol 1971;85:397‑404. 5. Molarte AB, Rosenbaum AL. Vertical rectus muscle transposition surgery for Duane’s syndrome. J Pediatr Ophthalmol Strabismus 1990;27:171‑7.
Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156965 PMID: ***
Respond to: Management of exotropic Duane retraction syndrome Dear Editor, We thank the authors for showing interest in our article Sharma et al.[1] For clinical management purpose, we have followed Jampolsky’s classification,[2] which would mostly comprise the Type II of Huber[3] and not Type III, herein considered as just exotropic Duane retraction syndrome (DRS). The esotropic DRS and Ortho DRS have to be tackled differently. One needs to clearly understand that the primary problem in all cases of DRS is paradoxic innervation of the lateral rectus (LR) during the adduction, and this cannot be eliminated by any procedure other than total extirpation or periosteal fixation of LR. In exotropic DRS, it is a good strategy to sacrifice the aberrant LR and convert the DRS into LR palsy and improve the abduction by transposition of the vertical recti. The adduction limitation in DRS is due to the co‑contraction of LR and medial rectus (MR) in adduction and improves on periosteal fixation of LR. No surgery on the ipsilateral MR is usually required. The MR is usually normal and should be confirmed by passive ductions, which are of paramount importance and have been mentioned as the first step in operative procedure in the methodology. Adduction improvement was not full in Group B due to the resting tone of partial vertical rectus transpositioning (pVRT) providing some resistance. The improved abduction, however, is minimal and is mainly due to the relaxed MR action during abduction. Following pVRT, the vertical vectors start working in synergy to aid the abduction tone with the inhibition of the tone of MR helps in abduction. The case A6 shown in picture had no improvement in abduction as shown in Table 1. However, it has been highlighted by Jampolsky, one should not be mistaking the degree of exodeviation as good abduction in exotropic DRS. Fig. 2 clearly demonstrates improved abduction. Statistical tests have not been claimed by us due to small numbers in this pilot study. Use of VRT in esotropic DRS with abnormal LR innervation can worsen retraction and upshoots and downshoots in adduction. In exotropic DRS, rather than graded recession of the aberrant LR, pVRT done as an adjustable procedure, along with the periosteal fixation seems to be better alternative and will be published soon. This study clearly establishes the role of periosteal fixation of LR to solve the paradoxic innervation and of the partial
292
Indian Journal of Ophthalmology
VRT to correct the esotropia thus created and also improves abduction as shown by the two groups. This strategy corrects the anomalous head posture, the deviation in the primary position, the retraction, narrowing of palpebral aperture and upshoots or downshoots in adduction, as well as improves the adduction and convergence, a vital function, as also improves the fields of binocular single vision. The improvement in abduction is minimal but a good value addition.
Pradeep Sharma, Ruchi Tomer, Vimla Menon, Rohit Saxena, Anudeepa Sharma Division of Strabismus and Neuro‑ophthalmology, R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India Correspondence to: Dr. Pradeep Sharma, Division of Strabismus, R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi - 110 029, India. E-mail: [email protected]
Table 1: Profile of patients with long‑term follow‑up Gender Eye
M M M F M M M F
References 1. Sharma P, Tomer R, Menon V, Saxena R, Sharma A. Evaluation of periosteal fixation of lateral rectus and partial VRT for cases of exotropic Duane retraction syndrome. Indian J Ophthalmol 2014;62:204‑8. 2. Jampolsky A. Duane syndrome. In: Rosenbaum AL, Santiago AP, editors. Clinical Strabismus Management. Philadelphia: WB Saunders; 1999. p. 325‑46. 3. Von Noorden GK. Binocular Vision and Ocular Motility: Theory and Management of Strabismus. 5th ed. St. Louis, Missouri: Mosby; 1996. p. 462. Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156970 PMID: ***
Comment on: Long‑term results after primary intraocular lens implantation in children operated less than 2 years of age for congenital cataract Dear Editor, We have read with great interest the article by Sukhija et al. published in the December 2014 edition.[1] We appreciate the sincere efforts of the authors. We very well understand the fact being a retrospective study, there are few limitations regarding data recording. However, there are a few short comings in the article that we would like to bring to notice. • In Table 1: Profile of patients with long‑term follow‑up, 4th female patient having preoperative axial length (AL)
Vol. 63 No. 3
M M F M M
Age at AL PO Final Final IOP Final surgery (mm) Ret. Refr. VA (mmHg) AL (months) (mm)
R
3
17.94
4
L
5
17.86
4
6/9
14
19.4
3.25 6/12
3
17
18.82
R
5
18.2
7
4
L
6
18.4
8
6.5
6/12
16
20.25
6/9
12
R
21
22.45 0.75
19.35
−1.5
6/9
17
L
22
22.55
23.19
0
0
6/9
19
R
22
21.9
23
4.5
3
6/9
13
20.04
L
23
22
R
23
20.3
2
0.75
6/9
15
19.96
−2.5 −3.25 6/12
12
L
16
19.04
3
−5
23.95
6/9
17
R
12
19.6
−1
23.93
−5
6/12
11
L
12
19.8
2
22.39
−3
6/12
13
R
16
20.7
0
21.86
0.25 6/12
12
L
17
20
2
22.15
6/12
12
22.22
R L
15
22.2 −2.75 −6.75 6/18
14
24.92
16
22.31
0
−3.5 6/12
12
23.63
R
17
20.6
1
0.25 6/12
17
22.4
L
18
20.7
0.5
6/12
17
22.6
R
13
20.95
1
−2.25 6/18
18
22.4
L
15
20.72
0
−3.75 6/18
32
22.89
R
12
19.5
3.5
6/18
17
21.23
L
13
19
5
1.75 6/12
16
21.66
R
12
18
0.5
6/18
16
22
L
15
17
0.25 −2.25 6/12
20
22.4
R L
13 16
17 17
24.45 25.46
−3
0
3.5 −4
18 −0.75 −9 18.5 −1.5 −11
6/36 6/36
AL: Axial length (in mm), PO: Postoperative, Ret.: Retinoscopy, Refr.: Refraction, VA: Visual acuity, IOP: Intraocular pressure
in right and left eye 21.9 mm and 22 mm, decreased to 20.04 mm and 19.96 mm respectively at last follow‑up. We are unable able to understand the cause of decrease AL on follow‑up • Method of AL measurement was not mentioned in detail? Whether AL was measured with contact technique or with immersion technique? The AL measured by contact A‑scan ultrasound can introduce the error because of the thinner and softer eye wall in children that is prone to deformation under pressure.[2] Previous study by Trivedi and Wilson had concluded that contact A‑scan measurements yielded shorter AL than immersion A‑scan measurements.[2] During intraocular lens (IOL) power calculation, if AL measured by contact technique is used, it will result in the use of an average 1D stronger IOL power than is actually required. This can lead to induced myopia in the postoperative refraction.[2] Out of 26 eyes, 5 eyes showed postoperative retinoscopy in negative (myopia), was it due to an error of measurement? They had not mentioned in detail why patients had first postoperative retinoscopy in minus • Which formula was used for IOL power calculation? Is the same IOL formula for all AL range (17–22.55 mm). Though they had aimed for a hypermetropic predictive postoperative retinoscopy, there were many eyes that were
March 2015
• •
•
•
Letters to the Editor
either myopic or emmetropic. This resulted in a larger myopic shift than expected in these eyes They had 5 patients with final refraction of myopia (−3 to − 11D). They had not discussed in details regarding various factors responsible for such high myopic shift[3] In Table 1, 3rd male patient with age at surgery 22 months, had postoperative retinoscopy 0. At last follow‑up, his refraction was also 0. Though there was an increase in AL by 0.5 mm there was no change in postoperative refraction after 8 years follow‑up Posterior capsule opacification (PCO) seen in two eyes. Which IOL was implanted in these eyes? Hydrophobic acrylic or single piece square edge polymethyl methacrylate. Previous studies had reported less PCO formation with hydrophobic acrylic IOL than with PMMA IOL[4] One patient had IOP 32 mmHg. Is IOP corrected for corneal thickness? As tonometry results may be influenced by the increased corneal thickness seen in aphakic and pseudophakic children so correction factor should be considered.
Khushbu Ramesh Bhattad, Amit Yadav, Ayesha F Shaikh, Pradhnya A Sen Department of Pediatric Ophthalmology, Sadguru Netra Chikitsalaya, Chitrakoot, Uttar Pradesh, India Correspondence to: Dr. Khushbu Ramesh Bhattad, Department of Pediatric Ophthalmology, Sadguru Netra Chikitsalaya, Jankikund, Chitrakoot, Uttar Pradesh, India. E‑mail: [email protected]
References 1. Sukhija J, Ram J, Gupta N, Sawhney A, Kaur S. Long‑term results after primary intraocular lens implantation in children operated less than 2 years of age for congenital cataract. Indian J Ophthalmol 2014;62:1132‑5. 2. Trivedi RH, Wilson ME. Axial length measurements by contact and immersion techniques in pediatric eyes with cataract. Ophthalmology 2011;118:498‑502. 3. Lam DS, Fan DS, Lam RF, Rao SK, Chong KS, Lau JT, et al. The effect of parental history of myopia on children’s eye size and growth: Results of a longitudinal study. Invest Ophthalmol Vis Sci 2008;49:873‑6. 4. Panahi‑Bazaz MR, Zamani M, Abazar B. Hydrophilic Acrylic versus PMMA Intraocular Lens Implantation in Pediatric Cataract Surgery. J Ophthalmic Vis Res 2009;4:201‑7. Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156972 PMID: ***
Conventional manual small-incision cataract surgery Sir, We read with interest the article by Yang et al.[1] describing good visual outcomes in manual cataract extraction via a
293
subconjunctival limbus oblique incision (SCOLI) for mature cataracts. Although the authors’ results are impressive, we would like to highlight that conventional manual small‑incision cataract surgery (MSICS) can also produce very good visual and refractive outcomes. Several studies have demonstrated that MSICS is safe and effective, even in advanced or complicated cataracts. Venkatesh et al.[2] described excellent visual outcomes of MSICS performed on a group of patients with brown and brunescent cataracts, with 97.1% achieving visual acuity (VA) of 6/18 or better with low complication rates. Another paper, also reported excellent outcomes in white cataracts,[3] with 98.2% achieving corrected distance VA of 6/18 or better. MSICS has also been shown to be safe in patients with phacolytic glaucoma,[4] demonstrating good visual outcomes with 87.9% of patients achieving good visual outcomes of 20/60 or better, while intraocular pressure was controlled without the need for long‑term anti‑glaucoma medications. Although the authors reported SCOLI induces less iatrogenic astigmatism due to its supero‑oblique incision,[1] Ruit et al.[5] had demonstrated that conventional MSICS can similarly reduce induced astigmatism by adopting a temporal approach. A recent Cochrane review[6] further suggests that conventional MSICS results in less surgically‑induced astigmatism compared to extra‑capsular cataract extraction. In summary, we congratulate the authors in promoting and teaching alternative techniques of cataract surgery that are safe, efficacious, and cost‑effective. In conjunction with the International Agency for the Prevention of Blindness and the World Health Organization Programme for Blindness and Deafness, this is part of a strategy to reduce cataract blindness globally. We feel that it is important for clinicians to consider the option of MSICS as part of their surgical repertoire.
Milton C Chew1, Colin S Tan1,2 Department of Ophthalmology, National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 2Fundus Image Reading Center, National Healthcare Group Eye Institute, Singapore 1
Correspondence to: Dr. Colin S Tan, National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433. E-mail: [email protected]
References 1. Yang J, Lai P, Wu D, Long Z. Manual cataract extraction via a subconjunctival limbus oblique incision for mature cataracts. Indian J Ophthalmol 2014;62:274‑8. 2. Venkatesh R, Tan CS, Singh GP, Veena K, Krishnan KT, Ravindran RD. Safety and efficacy of manual small incision cataract surgery for brunescent and black cataracts. Eye (Lond) 2009;23:1155‑7. 3. Venkatesh R, Tan CS, Sengupta S, Ravindran RD, Krishnan KT, Chang DF. Phacoemulsification versus manual small‑incision cataract surgery for white cataract. J Cataract Refract Surg 2010;36:1849‑54. 4. Venkatesh R, Tan CS, Kumar TT, Ravindran RD. Safety and efficacy of manual small incision cataract surgery for phacolytic glaucoma. Br J Ophthalmol 2007;91:279‑81.
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Indian Journal of Ophthalmology
Mehdi Modarres, Asgari Rezanejad, Khalil Ghasemi Falavarjani
acetonide injection at the end of phacoemulsification surgery. Indian J Ophthalmol 2014;62:861‑4. 2. Jabs DA, Nussenblatt RB, Rosenbaum JT, Standardization of Uveitis Nomenclature (SUN) Working Group. Standardization of Uveitis Nomenclature for reporting clinical data. Results of the First International Workshop. Am J Ophthalmol 2005;140:509‑16. 3. Karalezli A, Borazan M, Akova YA. Intracameral triamcinolone acetonide to control postoperative inflammation following cataract surgery with phacoemulsification. Acta Ophthalmol 2008;86:183‑7. Access this article online Quick Response Code: Website: www.ijo.in
Vol. 63 No. 3
Department of Ophthalmology, Eye Research Center, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran Correspondence to: Dr. Khalil Ghasemi Falavarjani, Eye Research Center, Rassoul Akram Hospital, Sattarkhan‑Niayesh Street, Tehran 14455 ‑ 364, Iran. E‑mail: [email protected]
References 1. Modarres M, Rezanejad A, Falavarjani KG. Recurrence and massive extraocular extension of choroidal malignant melanoma after vitrectomy and endoresection. Indian J Ophthalmol 2014;62:731‑3. 2. Rice JC, Stannard C, Cook C, Lecuona K, Myer L, Scholtz RP. Brachytherapy and endoresection for choroidal melanoma: A cohort study. Br J Ophthalmol 2014;98:86‑91. 3. Kertes PJ, Johnson JC, Peyman GA. Internal resection of posterior uveal melanomas. Br J Ophthalmol 1998;82:1147‑53.
Respond to: Safe endoresection Dear Sir, We thank Dr. Seider and Damato for critically reviewing our recent paper.[1] Apparently, they have some misunderstanding about the management of our patient. We hereby elucidate further. The patient had previously been managed in another center and the information we presented about her initial management 11 years ago was extracted from her old file in that center, which unfortunately was not adequate. All the information we could obtain was that the tumor has been 15 disc diameters in size, located in nasal quadrant, and associated with exudative retinal detachment. Enucleation had been suggested to her, but she refused. Therefore, endoresection was performed as one of the few available options. We would have recommended brachytherapy in addition to endoresection had we been in charge of this patient then. We do not know whether this option was suggested at that time, but it was not performed anyway. Reportedly, she was followed for 5 years, free of recurrence, and then was lost to follow‑up. We first examined the patient a few months ago when she referred with huge enlargement of the eye with multiple protruding dark brown masses as described in our paper, and she was immediately referred for orbital exenteration after detailed explanation of the situation. Even then, she accepted the treatment after a 2 months delay.
Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156959 PMID: ***
Role of part muscle vertical rectus transposition following periosteal fixation of the lateral rectus in exotropic Duane’s retraction syndrome Dear Sir, We read with interest the article by Sharma et al.[1] Since Duane’s retraction syndrome (DRS) is not garden variety strabismus, certain observations are in order. DRS can only be alleviated, not eliminated.
We agree that endoresection is an acceptable modality of treatment for tumors up to 18 mm in basal diameter, especially when in close proximity to optic disc and macula.[2,3] However, this patient’s eye has had an entirely different picture and was not suitable for endoresection. The surgery was performed out of obligation due to her refusal of enucleation.
In exo DRS, abnormal with subnormal lateral rectus (LR) along with occasionally subnormal medial rectus (MR) innervation may occur. MR may be stretched out/elongated. Globe retraction and shoots may disappear in large Exo DRS, and both horizontals may be stiff in relatively immobile globes with marked limitation of adduction and abduction. Muscle function tests are core to DRS evaluation but find fleeting reference here. Needless to say that each case is unique and graded procedures are in order rather than un‑titrated ones, as has happened here. Control group is lacking, inferences like efficacy may not stand scrutiny of statistical analysis.
The aim of presentation of this patient was not to point out the dangers of a properly performed endoresection, but to report the unfortunate consequences of a large melanoma for which endoresection was performed as the only available option in a patient who refused enucleation and did not comply with a regular follow‑up schedule.
Cohort is too diverse as both unilateral/bilateral cases have been included. Fixating eye in unilateral cases and whether bilateral cases are fusing or nonfusing DRS is not known. Fixation duress and deviation with either eye fixing are not known. Deviations in forced primary, abnormal head posture ( AHP) and shoots are not quantified, but inferences
March 2015
291
Letters to the Editor
are drawn. Type II DRS has only adduction limitation with normal abduction, authors are likely referring to type III DRS. Primary concerns in DRS are AHP, primary position (PP) deviation, globe retraction/narrowing of the palpebral fissure in adduction, shoots, A/V patterns, fixation duress, and decentration of binocular visual fields. Improvement in ductions/binocular visual fields is secondary as patients often suppress and do not complain of diplopia in side gazes. Lateral rectus periosteal fixation converts DRS into total 6th nerve palsy with attendant muscle sequaele. For aforesaid reasons, 33% patients (2 out of 6) developed an esotropia with rest having residual XT of 6 PD or greater. Authors have to throw some light as to how abduction improved in Group 1. In fact, it should worsen which is also evident in Fig. 1. In Group 2, most cases had undercorrected exotropia in PP, implying that ½ muscle vertical rectus transposition (VRT) adds to PP exotropia and may not have been indicated. Relearning of muscle function does not happen after transposition surgery as 3rd nerve nucleus is in the midbrain and 6th nerve nucleus in the pons, postulated innervational plasticity cannot occur.[2] Following VRT in LR palsy, vertical rectus muscles do not recruit in abduction and change in direction of vector forces was minimal.[3,4] Fig. 2 does not demonstrate improved abduction. Abducting force is generated in PP and improvement in abduction could only be due to relaxation of MR. VRT has been used in eso DRS with minimal abnormal LR innervation.[5] The claims of better abduction in Group 2 as compared to Group 1 are not supported by tests of statistical significance. Adduction improvement was not full in both groups implying that part of the problem lay with MR, which cannot be operated now, and surgery on the other eye is the only option. Under the circumstances, graded options other than periosteal fixation seem to be better.
Pramod Kumar Pandey, Vishaal Bhambhwani, Shagun Sood, Kartik Rana, Poonam Gupta, PC Ranjith Department of Ophthalmology, Guru Nanak Eye Centre and Maulana Azad Medical College, New Delhi, India Correspondence to: Dr. Pramod Kumar Pandey, Room No. 201, Guru Nanak Eye Centre, Maharaja Ranjit Singh Marg, New Delhi ‑ 110 002, India. E-mail: [email protected]
References 1. Sharma P, Tomar R, Menon V, Saxena R, Sharma A. Evaluation of periosteal fixation of lateral rectus and partial VRT for cases of exotropic Duane’s retraction syndrome. Indian J Ophthalmol 2014;62:204. 2. Metz HS, Scott AB. Innervational plasticity of the oculomotor system. Arch Ophthalmol 1970;84:86‑91. 3. Metz HS, Jampolsky A. Change in saccadic velocity following rectus muscle transposition. J Pediatr Ophthalmol Strabismus 1974;11:129. 4. Scott AB. Active force tests in lateral rectus paralysis. Arch Ophthalmol 1971;85:397‑404. 5. Molarte AB, Rosenbaum AL. Vertical rectus muscle transposition surgery for Duane’s syndrome. J Pediatr Ophthalmol Strabismus 1990;27:171‑7.
Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156965 PMID: ***
Respond to: Management of exotropic Duane retraction syndrome Dear Editor, We thank the authors for showing interest in our article Sharma et al.[1] For clinical management purpose, we have followed Jampolsky’s classification,[2] which would mostly comprise the Type II of Huber[3] and not Type III, herein considered as just exotropic Duane retraction syndrome (DRS). The esotropic DRS and Ortho DRS have to be tackled differently. One needs to clearly understand that the primary problem in all cases of DRS is paradoxic innervation of the lateral rectus (LR) during the adduction, and this cannot be eliminated by any procedure other than total extirpation or periosteal fixation of LR. In exotropic DRS, it is a good strategy to sacrifice the aberrant LR and convert the DRS into LR palsy and improve the abduction by transposition of the vertical recti. The adduction limitation in DRS is due to the co‑contraction of LR and medial rectus (MR) in adduction and improves on periosteal fixation of LR. No surgery on the ipsilateral MR is usually required. The MR is usually normal and should be confirmed by passive ductions, which are of paramount importance and have been mentioned as the first step in operative procedure in the methodology. Adduction improvement was not full in Group B due to the resting tone of partial vertical rectus transpositioning (pVRT) providing some resistance. The improved abduction, however, is minimal and is mainly due to the relaxed MR action during abduction. Following pVRT, the vertical vectors start working in synergy to aid the abduction tone with the inhibition of the tone of MR helps in abduction. The case A6 shown in picture had no improvement in abduction as shown in Table 1. However, it has been highlighted by Jampolsky, one should not be mistaking the degree of exodeviation as good abduction in exotropic DRS. Fig. 2 clearly demonstrates improved abduction. Statistical tests have not been claimed by us due to small numbers in this pilot study. Use of VRT in esotropic DRS with abnormal LR innervation can worsen retraction and upshoots and downshoots in adduction. In exotropic DRS, rather than graded recession of the aberrant LR, pVRT done as an adjustable procedure, along with the periosteal fixation seems to be better alternative and will be published soon. This study clearly establishes the role of periosteal fixation of LR to solve the paradoxic innervation and of the partial
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VRT to correct the esotropia thus created and also improves abduction as shown by the two groups. This strategy corrects the anomalous head posture, the deviation in the primary position, the retraction, narrowing of palpebral aperture and upshoots or downshoots in adduction, as well as improves the adduction and convergence, a vital function, as also improves the fields of binocular single vision. The improvement in abduction is minimal but a good value addition.
Pradeep Sharma, Ruchi Tomer, Vimla Menon, Rohit Saxena, Anudeepa Sharma Division of Strabismus and Neuro‑ophthalmology, R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India Correspondence to: Dr. Pradeep Sharma, Division of Strabismus, R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi - 110 029, India. E-mail: [email protected]
Table 1: Profile of patients with long‑term follow‑up Gender Eye
M M M F M M M F
References 1. Sharma P, Tomer R, Menon V, Saxena R, Sharma A. Evaluation of periosteal fixation of lateral rectus and partial VRT for cases of exotropic Duane retraction syndrome. Indian J Ophthalmol 2014;62:204‑8. 2. Jampolsky A. Duane syndrome. In: Rosenbaum AL, Santiago AP, editors. Clinical Strabismus Management. Philadelphia: WB Saunders; 1999. p. 325‑46. 3. Von Noorden GK. Binocular Vision and Ocular Motility: Theory and Management of Strabismus. 5th ed. St. Louis, Missouri: Mosby; 1996. p. 462. Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156970 PMID: ***
Comment on: Long‑term results after primary intraocular lens implantation in children operated less than 2 years of age for congenital cataract Dear Editor, We have read with great interest the article by Sukhija et al. published in the December 2014 edition.[1] We appreciate the sincere efforts of the authors. We very well understand the fact being a retrospective study, there are few limitations regarding data recording. However, there are a few short comings in the article that we would like to bring to notice. • In Table 1: Profile of patients with long‑term follow‑up, 4th female patient having preoperative axial length (AL)
Vol. 63 No. 3
M M F M M
Age at AL PO Final Final IOP Final surgery (mm) Ret. Refr. VA (mmHg) AL (months) (mm)
R
3
17.94
4
L
5
17.86
4
6/9
14
19.4
3.25 6/12
3
17
18.82
R
5
18.2
7
4
L
6
18.4
8
6.5
6/12
16
20.25
6/9
12
R
21
22.45 0.75
19.35
−1.5
6/9
17
L
22
22.55
23.19
0
0
6/9
19
R
22
21.9
23
4.5
3
6/9
13
20.04
L
23
22
R
23
20.3
2
0.75
6/9
15
19.96
−2.5 −3.25 6/12
12
L
16
19.04
3
−5
23.95
6/9
17
R
12
19.6
−1
23.93
−5
6/12
11
L
12
19.8
2
22.39
−3
6/12
13
R
16
20.7
0
21.86
0.25 6/12
12
L
17
20
2
22.15
6/12
12
22.22
R L
15
22.2 −2.75 −6.75 6/18
14
24.92
16
22.31
0
−3.5 6/12
12
23.63
R
17
20.6
1
0.25 6/12
17
22.4
L
18
20.7
0.5
6/12
17
22.6
R
13
20.95
1
−2.25 6/18
18
22.4
L
15
20.72
0
−3.75 6/18
32
22.89
R
12
19.5
3.5
6/18
17
21.23
L
13
19
5
1.75 6/12
16
21.66
R
12
18
0.5
6/18
16
22
L
15
17
0.25 −2.25 6/12
20
22.4
R L
13 16
17 17
24.45 25.46
−3
0
3.5 −4
18 −0.75 −9 18.5 −1.5 −11
6/36 6/36
AL: Axial length (in mm), PO: Postoperative, Ret.: Retinoscopy, Refr.: Refraction, VA: Visual acuity, IOP: Intraocular pressure
in right and left eye 21.9 mm and 22 mm, decreased to 20.04 mm and 19.96 mm respectively at last follow‑up. We are unable able to understand the cause of decrease AL on follow‑up • Method of AL measurement was not mentioned in detail? Whether AL was measured with contact technique or with immersion technique? The AL measured by contact A‑scan ultrasound can introduce the error because of the thinner and softer eye wall in children that is prone to deformation under pressure.[2] Previous study by Trivedi and Wilson had concluded that contact A‑scan measurements yielded shorter AL than immersion A‑scan measurements.[2] During intraocular lens (IOL) power calculation, if AL measured by contact technique is used, it will result in the use of an average 1D stronger IOL power than is actually required. This can lead to induced myopia in the postoperative refraction.[2] Out of 26 eyes, 5 eyes showed postoperative retinoscopy in negative (myopia), was it due to an error of measurement? They had not mentioned in detail why patients had first postoperative retinoscopy in minus • Which formula was used for IOL power calculation? Is the same IOL formula for all AL range (17–22.55 mm). Though they had aimed for a hypermetropic predictive postoperative retinoscopy, there were many eyes that were
March 2015
• •
•
•
Letters to the Editor
either myopic or emmetropic. This resulted in a larger myopic shift than expected in these eyes They had 5 patients with final refraction of myopia (−3 to − 11D). They had not discussed in details regarding various factors responsible for such high myopic shift[3] In Table 1, 3rd male patient with age at surgery 22 months, had postoperative retinoscopy 0. At last follow‑up, his refraction was also 0. Though there was an increase in AL by 0.5 mm there was no change in postoperative refraction after 8 years follow‑up Posterior capsule opacification (PCO) seen in two eyes. Which IOL was implanted in these eyes? Hydrophobic acrylic or single piece square edge polymethyl methacrylate. Previous studies had reported less PCO formation with hydrophobic acrylic IOL than with PMMA IOL[4] One patient had IOP 32 mmHg. Is IOP corrected for corneal thickness? As tonometry results may be influenced by the increased corneal thickness seen in aphakic and pseudophakic children so correction factor should be considered.
Khushbu Ramesh Bhattad, Amit Yadav, Ayesha F Shaikh, Pradhnya A Sen Department of Pediatric Ophthalmology, Sadguru Netra Chikitsalaya, Chitrakoot, Uttar Pradesh, India Correspondence to: Dr. Khushbu Ramesh Bhattad, Department of Pediatric Ophthalmology, Sadguru Netra Chikitsalaya, Jankikund, Chitrakoot, Uttar Pradesh, India. E‑mail: [email protected]
References 1. Sukhija J, Ram J, Gupta N, Sawhney A, Kaur S. Long‑term results after primary intraocular lens implantation in children operated less than 2 years of age for congenital cataract. Indian J Ophthalmol 2014;62:1132‑5. 2. Trivedi RH, Wilson ME. Axial length measurements by contact and immersion techniques in pediatric eyes with cataract. Ophthalmology 2011;118:498‑502. 3. Lam DS, Fan DS, Lam RF, Rao SK, Chong KS, Lau JT, et al. The effect of parental history of myopia on children’s eye size and growth: Results of a longitudinal study. Invest Ophthalmol Vis Sci 2008;49:873‑6. 4. Panahi‑Bazaz MR, Zamani M, Abazar B. Hydrophilic Acrylic versus PMMA Intraocular Lens Implantation in Pediatric Cataract Surgery. J Ophthalmic Vis Res 2009;4:201‑7. Access this article online Quick Response Code:
Website: www.ijo.in DOI: 10.4103/0301-4738.156972 PMID: ***
Conventional manual small-incision cataract surgery Sir, We read with interest the article by Yang et al.[1] describing good visual outcomes in manual cataract extraction via a
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subconjunctival limbus oblique incision (SCOLI) for mature cataracts. Although the authors’ results are impressive, we would like to highlight that conventional manual small‑incision cataract surgery (MSICS) can also produce very good visual and refractive outcomes. Several studies have demonstrated that MSICS is safe and effective, even in advanced or complicated cataracts. Venkatesh et al.[2] described excellent visual outcomes of MSICS performed on a group of patients with brown and brunescent cataracts, with 97.1% achieving visual acuity (VA) of 6/18 or better with low complication rates. Another paper, also reported excellent outcomes in white cataracts,[3] with 98.2% achieving corrected distance VA of 6/18 or better. MSICS has also been shown to be safe in patients with phacolytic glaucoma,[4] demonstrating good visual outcomes with 87.9% of patients achieving good visual outcomes of 20/60 or better, while intraocular pressure was controlled without the need for long‑term anti‑glaucoma medications. Although the authors reported SCOLI induces less iatrogenic astigmatism due to its supero‑oblique incision,[1] Ruit et al.[5] had demonstrated that conventional MSICS can similarly reduce induced astigmatism by adopting a temporal approach. A recent Cochrane review[6] further suggests that conventional MSICS results in less surgically‑induced astigmatism compared to extra‑capsular cataract extraction. In summary, we congratulate the authors in promoting and teaching alternative techniques of cataract surgery that are safe, efficacious, and cost‑effective. In conjunction with the International Agency for the Prevention of Blindness and the World Health Organization Programme for Blindness and Deafness, this is part of a strategy to reduce cataract blindness globally. We feel that it is important for clinicians to consider the option of MSICS as part of their surgical repertoire.
Milton C Chew1, Colin S Tan1,2 Department of Ophthalmology, National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 2Fundus Image Reading Center, National Healthcare Group Eye Institute, Singapore 1
Correspondence to: Dr. Colin S Tan, National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433. E-mail: [email protected]
References 1. Yang J, Lai P, Wu D, Long Z. Manual cataract extraction via a subconjunctival limbus oblique incision for mature cataracts. Indian J Ophthalmol 2014;62:274‑8. 2. Venkatesh R, Tan CS, Singh GP, Veena K, Krishnan KT, Ravindran RD. Safety and efficacy of manual small incision cataract surgery for brunescent and black cataracts. Eye (Lond) 2009;23:1155‑7. 3. Venkatesh R, Tan CS, Sengupta S, Ravindran RD, Krishnan KT, Chang DF. Phacoemulsification versus manual small‑incision cataract surgery for white cataract. J Cataract Refract Surg 2010;36:1849‑54. 4. Venkatesh R, Tan CS, Kumar TT, Ravindran RD. Safety and efficacy of manual small incision cataract surgery for phacolytic glaucoma. Br J Ophthalmol 2007;91:279‑81.
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