Title of Invention	GRID SYSTEM FOR OBJECTIVELY ESTIMATING THE AREA OF RETINAL ISCHEMIA ON FUNDUS FLUORESCEIN ANGIOGRAPHY OF EYES
Abstract	Grid system for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes, comprises a pair of grids, one of the grids meant for inspection of the right eye and another, for inspection of the left eye, the said right eye grid and left eye grid are detachably attached by a fastening system and further held in position in a plastic pouch such that by super imposing one grid on the angiogram it is . possible to assess objevtively the area of non-perfusion in the eye.

Title of Invention

GRID SYSTEM FOR OBJECTIVELY ESTIMATING THE AREA OF RETINAL ISCHEMIA ON FUNDUS FLUORESCEIN ANGIOGRAPHY OF EYES

Abstract

Grid system for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes, comprises a pair of grids, one of the grids meant for inspection of the right eye and another, for inspection of the left eye, the said right eye grid and left eye grid are detachably attached by a fastening system and further held in position in a plastic pouch such that by super imposing one grid on the angiogram it is . possible to assess objevtively the area of non-perfusion in the eye.

Full Text	This invention in general relates to diagnostic instruments in the field of medical technology and science. This invention in particular relates to instruments accessories used for deducing or objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes. Fundus fluorescien angiography is a technique of evaluating blood circulation within the eye. To estimate of area of retinal no perfusion, (ischemia), the area which appears hypofluorescent is noted. Areas within the fundus of the eye are measured in disc diameters, the diameter of the optic disc. The device according to the invention has a pair of grids, one grid for deduction of retinal ischemia on fundus fluorescein angiography in the right eye and another grid for the deduction of the same in the left eye, the said grids are detachably attached, secured by means of a fastening device, the said grids and fastener being placed in a plastic pouch. The conventional method of estimating the area of retinal non perfusion is done subjectively by the ophthalmologist. The result of the aforesaid method is capable of being under/over estimated, the area being under/over estimated. The area of retinal non perfusion is, by convention, measured in disc diameters. The subjective process is by way of approximation and, being subjective, the method of measuring is prone to error. The main objective of the invention is to overcome the aforesaid problem. To this end, this novel grid was developed. The conventional method of estimating the area of retinal non perfusion is based on the visual impression of an ophthalmologist. As a result the area may be underestimated or overestimated. The area of retinal non perfusion is measured in disc diameters. As an analogy, one can estimate the length of an object visually, ie 10 cms, but to precisely say its length, one would have lo measure it.s length using a scale. So also, the grid according to the invention can help the ophthalmologist lo assess objectively the area of retinal ischemia, or the area which has lost its blood supply. This will enable the ophthalmologist to make a decision as to whether laser treatment is essential or not. The primary object of the invention is to invent a grid for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes. Another object of the invention is to invent a grid by virtue of which objective examination of the retina (the inner nervous layer of the eye) is possible. Other objects of the invention will be apparent from the ensuing description. Statement of invention : The present invention pertains to a grid system for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes, the said grid system comprising a pair of grids, one meant for inspection of the Right eye and another for inspection of the Left eye, the said Right eye grid and Left eye grid are detachably attached by a fastening system and placed in a plastic pouch such that by super imposing one grid on the angiogram of the fundus of the eye one can assess objectively the area of non-perfusion in the eye. Now the invention will be described in detail with reference to drawing, accompanying this specification wherein : Fig. 1 to 4 show various stages of construction of the grid for use in the right eye according to the invention. Fig. 5 to 8 show the stages of construction of the grid for use in the left eye. Fig. 9 shows the device according to the invention containing a left eye grid and right eye grid detachably secured and kept in a plastic pouch. This grid is a diagram within the outline/frame of the fluorescein angiographic field. In this case (Canon CF 60 U Fundus Camera) it was bounded by horizontal lines 1.9 cm long and separated by a distance of 2.1 cm. The widest area of the grid (1.05 cms from each of the two horizontal lines) measures 2.8 cms. The ends of the three lines are joined by an arc as shown in Fig. 1. By noting the exact size of the normal optic disc/optic nerve head on the normal angiographic field, a circle of diameter 0.3 cms is drawn on the widest line of the grid, as in Fig. 1 for Left eye and as in Fig. 5 for Right eye. The series of steps in the process of manufacturing each grid, one lor the left eye and another for the right eye, are shown together for clear understanding and clarity of the salient features of the invention. The entire frame is covered by circles of the same diameter by computer aided design, Fig. 2 for Left eye and Fig. 6 for Right Eye. To enable the viewer to accurately place the grid on the angiogram, the optic nerve head is shaded, as in Fig. 3 for Left eye and as in Fig. 7 for Right Eye. In order to simplify the grid the outline of the grid was omitted as in Fig. 4 for Left Eye, and Fig. 8 for Right Eye. By transferring the outline of the grid on to a transparent surface, it is possible to superimpose the grid on an angiogram and assess objectively the area of nonperfusion, in the eye. This is in effect the salient feature of the invention. It can also be used to measure distances on photographs of the retina (the inner nervous layer of the eye). The obvious advantage of the invention is to objectively estimate the area of retinal ischemia on fundus fluorescein angiography of eyes, measure distances on the retina. It is to be noted that the object of the description and illustration, by way of an embodiment of the invention is to illustrate the salient features of the invention. It is to be noted that the description in no way limits the scope and ambit of the invention, ^t is apparent that within the scope and ambit of the invention, various amendments and modifications are permissible. The scope of the invention is defined in the above description. I Claim 1. Grid system for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes, the said grid system comprising a pair of grids, one of the grids meant for inspection of the right eye and another for inspection of the left eye, the said right eye grid and left eye grid are detachably attached by a clip and placed in a transparant plastic pouch, such that by super imposing one grid on the angiogram of the fundus of the eye one can assess objectively the area of non- perfusion in the eye. 2. Grid system for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes, as described in this specification and as illustrated in the drawings accompanying the specification.

Full Text

This invention in general relates to diagnostic instruments in the field of medical technology and science. This invention in particular relates to instruments accessories used for deducing or objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes.
Fundus fluorescien angiography is a technique of evaluating blood circulation within the eye. To estimate of area of retinal no perfusion, (ischemia), the area which appears hypofluorescent is noted. Areas within the fundus of the eye are measured in disc diameters, the diameter of the optic disc.
The device according to the invention has a pair of grids, one grid for deduction of retinal ischemia on fundus fluorescein angiography in the right eye and another grid for the deduction of the same in the left eye, the said grids are detachably attached, secured by means of a fastening device, the said grids and fastener being placed in a plastic pouch.
The conventional method of estimating the area of retinal non perfusion is done subjectively by the ophthalmologist. The result of the aforesaid method is capable of being under/over estimated, the area being under/over estimated. The area of retinal non perfusion is, by convention, measured in disc diameters. The subjective process is by way of approximation and, being subjective, the method of measuring is prone to error. The main objective of the invention is to overcome the aforesaid problem. To this end, this novel grid was developed. The conventional method of estimating the area of retinal non perfusion is based on the visual impression of an ophthalmologist. As a result the area may be underestimated or overestimated. The area of retinal non perfusion is measured in disc diameters.

As an analogy, one can estimate the length of an object visually, ie 10 cms, but to precisely say its length, one would have lo measure it.s length using a scale. So also, the grid according to the invention can help the ophthalmologist lo assess objectively the area of retinal ischemia, or the area which has lost its blood supply. This will enable the ophthalmologist to make a decision as to whether laser treatment is essential or not.
The primary object of the invention is to invent a grid for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes.
Another object of the invention is to invent a grid by virtue of which objective examination of the retina (the inner nervous layer of the eye) is possible.
Other objects of the invention will be apparent from the ensuing description. Statement of invention :
The present invention pertains to a grid system for objectively estimating the area of retinal ischemia on fundus fluorescein angiography of eyes, the said grid system comprising a pair of grids, one meant for inspection of the Right eye and another for inspection of the Left eye, the said Right eye grid and Left eye grid are detachably attached by a fastening system and placed in a plastic pouch such that by super imposing one grid on the angiogram of the fundus of the eye one can assess objectively the area of non-perfusion in the eye.

Now the invention will be described in detail with reference to drawing, accompanying this specification wherein :
Fig. 1 to 4 show various stages of construction of the grid for use in the right eye according to the invention.
Fig. 5 to 8 show the stages of construction of the grid for use in the left eye.
Fig. 9 shows the device according to the invention containing a left eye grid and right eye grid detachably secured and kept in a plastic pouch.
This grid is a diagram within the outline/frame of the fluorescein angiographic field. In this case (Canon CF 60 U Fundus Camera) it was bounded by horizontal lines 1.9 cm long and separated by a distance of 2.1 cm. The widest area of the grid (1.05 cms from each of the two horizontal lines) measures 2.8 cms. The ends of the three lines are joined by an arc as shown in Fig. 1. By noting the exact size of the normal optic disc/optic nerve head on the normal angiographic field, a circle of diameter 0.3 cms is drawn on the widest line of the grid, as in Fig. 1 for Left eye and as in Fig. 5 for Right eye.
The series of steps in the process of manufacturing each grid, one lor the left eye and another for the right eye, are shown together for clear understanding and clarity of the salient features of the invention.

The entire frame is covered by circles of the same diameter by computer aided design, Fig. 2 for Left eye and Fig. 6 for Right Eye. To enable the viewer to accurately place the grid on the angiogram, the optic nerve head is shaded, as in Fig. 3 for Left eye and as in Fig. 7 for Right Eye. In order to simplify the grid the outline of the grid was omitted as in Fig. 4 for Left Eye, and Fig. 8 for Right Eye. By transferring the outline of the grid on to a transparent surface, it is possible to superimpose the grid on an angiogram and assess objectively the area of nonperfusion, in the eye. This is in effect the salient feature of the invention. It can also be used to measure distances on photographs of the retina (the inner nervous layer of the eye).
The obvious advantage of the invention is to objectively estimate the area of retinal ischemia on fundus fluorescein angiography of eyes, measure distances on the retina.
It is to be noted that the object of the description and illustration, by way of an embodiment of the invention is to illustrate the salient features of the invention. It is to be noted that the description in no way limits the scope and ambit of the invention, ^t is apparent that within the scope and ambit of the invention, various amendments and modifications are permissible. The scope of the invention is defined in the above description.

I Claim
1. Grid system for objectively estimating the area of retinal ischemia on fundus
fluorescein angiography of eyes, the said grid system comprising a pair of grids, one
of the grids meant for inspection of the right eye and another for inspection of the left
eye, the said right eye grid and left eye grid are detachably attached by a clip and
placed in a transparant plastic pouch, such that by super imposing one grid on the
angiogram of the fundus of the eye one can assess objectively the area of non-
perfusion in the eye.
2. Grid system for objectively estimating the area of retinal ischemia on fundus
fluorescein angiography of eyes, as described in this specification and as illustrated in
the drawings accompanying the specification.

Documents:

1665-mas-1998 abstract.pdf

1665-mas-1998 claims-duplicate.pdf

1665-mas-1998 claims.pdf

1665-mas-1998 correspondence-others.pdf

1665-mas-1998 correspondence-po.pdf

1665-mas-1998 description(complete)-duplicate.pdf

1665-mas-1998 description(complete).pdf

1665-mas-1998 drawings.pdf

1665-mas-1998 form-1.pdf

1665-mas-1998 form-19.pdf

1665-mas-1998 form-26.pdf

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Patent Number

217251

Indian Patent Application Number

1665/MAS/1998

PG Journal Number

21/2008

Publication Date

23-May-2008

Grant Date

26-Mar-2008

Date of Filing

27-Jul-1998

Name of Patentee

IRVATHUR VITTAL NAYAK

Applicant Address

HARI-OM, 1656, 10TH MAIN, HAL 3RD STAGE, BANGALORE - 560 075,

Inventors:

#	Inventor's Name	Inventor's Address
1	IRVATHUR VITTAL NAYAK	HARI-OM, 1656, 10TH MAIN, HAL 3RD STAGE, BANGALORE - 560 075,

PCT International Classification Number

G02C 007/16

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA