RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, KARNATAKA, BANGALORE.
PROFORMA FOR REGISTRATION OF TOPIC FOR DISSERTATION
1. NAME OF CANDIDATE – Dr DivyaRaju
ADDRESS OF CANDIDATE – 802’ A’ VaswaniPinnacle ,
Whitefield main road, Bangalore 560066
2. NAME OF THE INSTITUTE – Vydehi Institute of Medical sciences and research centre, Bangalore 560066
3. COURSE OF STUDY AND SUBJECT- MS in Ophthalmology
4. DATE OF ADMISSION TO COURSE – 19 May 2010
5. TITLE OF TOPIC –A study of association between incidence of pterygium and morphology of horizontal rectus muscle insertion.
6. BRIEF RESUME OF INTENDED WORK
6.1 NEED FOR STUDY
Pterygium is a common ocular problem in tropical countries, thought
to be due to increased exposure to UV-B radiation, dry, hot, windy,
dusty conditions.(1)
Pterygia occur in the palpebral aperture- nasal and temporal limbus.
The horizontal recti- medial and lateral are inserted on the sclera 5.5mm (medial rectus) and 6.9 mm (lateral rectus) away from the limbus,
parallel to it, at the 3o’clock and 9o’clock meridia. The width of insertion
of medial and lateral recti tendons are, 10.3mm and 9.2mm respectively. (2)
Recurrence is a common complication following surgery, due to
reexposure to the etiological factors.
The incidence ofpterygium in India is on an average 5.2%
(range0.75% to 10.42%)(3).
An observation has been made by the Ophthalmologydepartment,
VIMS&RC, that occurrence of pterygium is more common when the insertion
of the horizontal recti muscles are more anterior than normal/ have abnormalmorphology.
These observations, have not been documented, nor have there been any previous studies done on this topic.
In view of the observations made, we would like to conduct this study to give documentary evidence of whether or not the anterior insertion/ abnormal morphology of horizontal recti muscles have any association with occurrence
ofpterygium.
6.2 REVIEW OF LITERATURE
Prevalence of pterygium is seen to be as high as 22% in the equatorial
area and less than 2% in areas above 40° latitudes according to the global
survey of pterygium conducted in Springfield, Illinois, in 1965, by
Cameron.(4)
The prevalence of pterygium, in India, ranges from as low as 0.75% to
as high as 10.42% in different states, and an overall average in prevalence being 5.2%, according to studies conducted by PGIME, Chandigarh, India, 1997.(3)
Studies at theNational University, Singapore in 1999(1), showed that the
risk factors for development of pterygium are dry, hot, windy and dusty environments. According to the Barbados eye study, 2001,pterygium is
2.5-3 times more common in black population and is almost twice as
common in people who work outdoors(5).
The Blue mountain eye study at the University of Sydney, Australia,
in 1997, found significant association between pterygium and increased pigmentation,and sun related skin damage.(6)
Recurrence rates are highly variable, based on type of excision done (with
or without graft), type of graft, and postoperative treatment given.
Recurrence rates vary from 40-90% according to several studies done at Princess Alexandra Hospital, Australia in 1991, and Rabin Medical
Centre, Haife, Israel in 2001.(7) (8)
6.3 OBJECTIVE OF THE STUDY
To establish an association between the incidence of primary and
recurrentpterygium and the following factors:-
1.Anterior insertion of the horizontal recti muscles:-
2.Width of the insertion.
3.Morphology of insertion- shape and vascularity
.
7. MATERIAL AND METHODS
7.1 SOURCE OF DATA
Cohort study in which all patients undergoing pterygium surgery in VIMS&RC will be considered.
7.2 METHOD OF COLLECTION OF DATA
· Informed written consent of the participating patients will be taken
· A pre structured proforma shall be used to collect the baseline data
· Detailed history will be taken and clinical/ ocular examination done.
· Routine pre operative investigations will be done.
· Distance between insertion of horizontal recti and the limbus will be measured (9 and 3 o’clock position for the medial and lateral recti muscles respectively) during the procedure using a Castroviejo
measuringcaliper.
· Width of insertion will be measured using the Castroviejo measuring caliper.
· The shape of insertion as well as the vascularity will be noted.
· Procedure: Pterygium excision with or without conjunctival auto graft.
STATISTICAL ANALYSIS:
It is a time bound study from December 2010 to April 2012.
Data will be analyzed using:Z- test , Mean , Standard deviation,
andPercentage.
INCLUSION CRITERIA
· All subjects with pterygium, presenting to Ophthalmology OPD,
and undergoing surgical treatment for the same.
EXCLUSION CRITERIA
· Subjects with severe dry eye. (Schirmers test 2 less than 4mm)
· Subjects with Grade 4 allergic conjunctivitis. (Biomicroscopy shows cobble stone appearance on the palpebral conjunctiva)
· Subjects with strabismus/ those who underwent strabismus surgery
7.3 REQUIRED INVESTIGATIONS AND INTERVENTIONS
· Routine investigations for pterygium surgery – complete blood count, FBS, PPBS, Bl. Urea &Creatinin, urine routine, ECG.
· Tests to exclude dry eye – Schirmer’s test 1, Schirmer’s test 2, Tear film breakup time, Flourescein dye disappearance test, Rose Bengal staining.
7.4 ETHICAL CLEARANCE
Yes.
8. LIST OF REFERENCES
1. Saw SM, Banerjee K, Tan D. Risk factors for development of
pterygium in Singapore: a hospital based study. Ophthalmic Epidemol
1999; 6(3): 219-28.
2. Roper-Hall, M.J, Stallard’s eye surgery, Bombay: Varghese
publishing House, 1989, 164, Fig.5.1.
3. MM Singh, GV Murthy, R Venkataraman. A study of ocular
morbidity among elderly population in rural central India. IJO 1997;
45(1): 61-65.
4. Cameron ME. Geographic distribution of Pterygia, Trans
Ophthalmolo Soc Aust 1962; 22: 67-81.
5. Luthra R et al. Frequency and risk factors for pterygium in the
Barbados Eye Study. Arch Ophthalmol 2001;119(12): 1827-32.
6. Panchapakesan J, Haurihan F, Mitchell P. Prevalence of pterygium
andpingencula: the Blue Mountain Eye Study, Aust NZJ Ophthalmol
1998; 26(1): 2-5.
7. Hirst LW, Sebban A, Chant D. Pterygium recurrence time, Ophthalmology 1994; 101(4): 755-8.
8. AvisarRahanim, AronAharon, AvisarErez. Primary pterygium recurrence time, IMAJ 2001; 3: 836-37.
9.SIGNATURE OF THE CANDIDATE
10.REMARKS OF THE GUIDE
The topic investigates a very common clinical problem; and will
definitely aid in practical surgical management of pterygium, both
primary and recurrent.
The study is feasible and recommended.
11. 1 GUIDE-
Dr I VittalNayak,
MS Ophthalmology
Professor & HOD,
Dept of Ophthalmology,
VIMS&RC
11.2 SIGNATURE OF GUIDE –
11.3 HEAD OF DEPARMENT
Dr I VittalNayak,
MS Ophthalmology,
Professor & HOD,
Dept of Ophthalmology,
VIMS&RC
11.4 SIGNATURE OF HOD
12.1 REMARKS OF PRINCIPAL
12.2 SIGNATURE OF PRINCIPAL